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Emergency And Acute Medicine – Congenital Heart Disease, Cyanotic
Description
Cyanotic congenital heart disease results from abnormal embryologic cardiac development that allows mixing of deoxygenated and oxygenated blood into the systemic circulation. This occurs through right-to-left intracardiac shunting or anatomic defects involving the great vessels. Classic subtypes include the “five Ts,” the “two Es,” and single-ventricle physiology. These conditions include tetralogy of Fallot, transposition of the great arteries, tricuspid atresia, truncus arteriosus, total anomalous pulmonary venous return, Ebstein anomaly of the tricuspid valve, Eisenmenger syndrome, and single-ventricle physiology. All lead to varying degrees of systemic hypoxemia.
Etiology
For most cyanotic congenital heart defects, the precise cause is unknown. Genetic and environmental contributions may play a role, but no single unifying etiology is identified in the majority of cases.
Emergency Presentation
The most common initial emergency department presentations include central cyanosis, congestive heart failure, and circulatory collapse. In older children with known cyanotic heart disease, physiologic stress such as fever, dehydration, pulmonary disease, decreased systemic vascular resistance, or obstruction of a cardiac shunt can precipitate worsening cyanosis.
Clinical Features
Central cyanosis is typically visible in the lips, nail beds, and mucous membranes and worsens with crying or agitation, with minimal improvement on administration of 100% oxygen. Signs of congestive heart failure include rales, gallop rhythm, hepatomegaly, and scalp edema. Hypercyanotic spells, or “Tet spells,” present with restlessness, hyperpnea, progressive cyanosis, and possible syncope, often triggered by feeding, crying, or exertion. Older children may instinctively squat to improve symptoms.
History
A family history of congenital heart disease increases risk, especially if a parent or sibling is affected. Prenatal history may reveal teratogen exposure or abnormal fetal ultrasound findings. Tetralogy of Fallot is often asymptomatic at birth, with symptoms developing as right ventricular outflow obstruction worsens. Tricuspid atresia usually presents with cyanosis from birth. Ebstein anomaly may present later in adolescence with dysrhythmias. Transposition of the great arteries often presents within the first hours to days of life. Total anomalous pulmonary venous return may present with severe neonatal illness or later with heart failure if unobstructed. Truncus arteriosus causes mild neonatal cyanosis with progressive heart failure in infancy.
Physical Examination
Tetralogy of Fallot is characterized by a loud systolic murmur along the left sternal border, a single loud second heart sound, and right ventricular prominence. Chronic disease leads to clubbing and retinal engorgement. Tricuspid atresia presents with tachypnea, a regurgitant murmur from an associated ventricular septal defect, a single second heart sound, and a prominent left ventricular impulse. Ebstein anomaly produces holosystolic tricuspid regurgitation murmurs and may include gallop rhythms. Transposition of the great arteries is notable for severe hypoxemia with a single loud second heart sound. Total anomalous pulmonary venous return presents with tachypnea, murmurs, fixed split second heart sound, and hepatomegaly. Truncus arteriosus causes bounding pulses, wide pulse pressure, a loud single second heart sound, and systolic and diastolic murmurs.
Essential Diagnostic Evaluation
Initial evaluation includes pulse oximetry, arterial blood gas analysis, complete blood count, glucose testing, and a full sepsis evaluation. Chest radiography assesses pulmonary blood flow, while electrocardiography evaluates chamber hypertrophy and axis deviation. Early cardiology consultation is essential.
Diagnostic Tests And Interpretation
Arterial blood gases show reduced oxygen saturation on room air. The hyperoxia test helps differentiate pulmonary disease from cyanotic congenital heart disease, with a PaO₂ less than 100 mm Hg after 100% oxygen strongly suggesting intracardiac shunting. Chronic cyanosis leads to erythrocytosis on complete blood count. Chest radiography may show decreased pulmonary blood flow in tetralogy of Fallot or tricuspid atresia and increased flow in transposition, total anomalous pulmonary venous return, and truncus arteriosus. Classic radiographic signs include the boot-shaped heart of tetralogy of Fallot, the egg-on-a-string appearance of transposition of the great arteries, and the snowman sign in supracardiac total anomalous pulmonary venous return. Electrocardiography demonstrates characteristic patterns of axis deviation and ventricular hypertrophy depending on the lesion.
Differential Diagnosis
The differential includes pulmonary causes such as pneumothorax, pulmonary hypertension, pneumonia, bronchiolitis, and diaphragmatic hernia; cardiac causes such as congestive heart failure and cardiogenic shock; infectious causes including sepsis; neurologic causes such as seizures; and metabolic or hematologic conditions including hypoglycemia, dehydration, polycythemia, and methemoglobinemia.
Initial Stabilization And Therapy
Management focuses on maintaining warmth, correcting hypoglycemia and acidosis, ensuring adequate oxygenation, establishing intravenous access, and preparing for airway support. Excessive oxygen should be avoided because high oxygen tension promotes ductal closure. Air filters should be placed on intravenous lines to prevent paradoxical emboli.
Emergency Department Management
Prostaglandin E1 infusion should be initiated in duct-dependent lesions to maintain or reopen the ductus arteriosus, typically at 0.05–0.1 μg/kg/min. Complications include apnea, bradycardia, hypotension, and seizures, so airway readiness is essential. Prostaglandin is ineffective in obstructed total anomalous pulmonary venous return, which may require extracorporeal support. Fluid resuscitation should be performed cautiously in 10 mL/kg increments. Hypercyanotic spells are managed with a calm environment, knee-chest positioning, supplemental oxygen if tolerated, and morphine. Severe cases may require bicarbonate, phenylephrine to increase systemic vascular resistance, or propranolol for beta-blockade. Circulatory collapse requires aggressive resuscitation with fluids, inotropes, and correction of acidosis.
Medications
Commonly used medications include prostaglandin E1, morphine, phenylephrine, propranolol, dopamine, dobutamine, milrinone, antibiotics such as ampicillin and gentamicin, antipyretics, and sodium bicarbonate when indicated.
Disposition And Follow-Up
All newborns with suspected cyanotic congenital heart disease require admission to a pediatric intensive care unit. Admission is also indicated for acute worsening of cyanosis, heart failure, or respiratory infection. Discharge decisions should be made in consultation with pediatric cardiology and reserved for carefully selected, stable patients with ensured close follow-up.
Referral And Follow-Up Recommendations
Care should be coordinated among primary care providers, pediatric cardiologists, and cardiothoracic surgeons. Clear follow-up plans and return precautions are essential, as physiologic stress can rapidly worsen clinical status.
Clinical Pearls And Pitfalls
Visible cyanosis requires significant levels of deoxygenated hemoglobin. Duct-dependent lesions often present at two to three weeks of age with sudden cyanosis or cardiovascular collapse. Prostaglandin E1 can be lifesaving but requires close monitoring for apnea and hypotension.
Description
Cyanotic congenital heart disease results from abnormal embryologic cardiac development that allows mixing of deoxygenated and oxygenated blood into the systemic circulation. This occurs through right-to-left intracardiac shunting or anatomic defects involving the great vessels. Classic subtypes include the “five Ts,” the “two Es,” and single-ventricle physiology. These conditions include tetralogy of Fallot, transposition of the great arteries, tricuspid atresia, truncus arteriosus, total anomalous pulmonary venous return, Ebstein anomaly of the tricuspid valve, Eisenmenger syndrome, and single-ventricle physiology. All lead to varying degrees of systemic hypoxemia.
Etiology
For most cyanotic congenital heart defects, the precise cause is unknown. Genetic and environmental contributions may play a role, but no single unifying etiology is identified in the majority of cases.
Emergency Presentation
The most common initial emergency department presentations include central cyanosis, congestive heart failure, and circulatory collapse. In older children with known cyanotic heart disease, physiologic stress such as fever, dehydration, pulmonary disease, decreased systemic vascular resistance, or obstruction of a cardiac shunt can precipitate worsening cyanosis.
Clinical Features
Central cyanosis is typically visible in the lips, nail beds, and mucous membranes and worsens with crying or agitation, with minimal improvement on administration of 100% oxygen. Signs of congestive heart failure include rales, gallop rhythm, hepatomegaly, and scalp edema. Hypercyanotic spells, or “Tet spells,” present with restlessness, hyperpnea, progressive cyanosis, and possible syncope, often triggered by feeding, crying, or exertion. Older children may instinctively squat to improve symptoms.
History
A family history of congenital heart disease increases risk, especially if a parent or sibling is affected. Prenatal history may reveal teratogen exposure or abnormal fetal ultrasound findings. Tetralogy of Fallot is often asymptomatic at birth, with symptoms developing as right ventricular outflow obstruction worsens. Tricuspid atresia usually presents with cyanosis from birth. Ebstein anomaly may present later in adolescence with dysrhythmias. Transposition of the great arteries often presents within the first hours to days of life. Total anomalous pulmonary venous return may present with severe neonatal illness or later with heart failure if unobstructed. Truncus arteriosus causes mild neonatal cyanosis with progressive heart failure in infancy.
Physical Examination
Tetralogy of Fallot is characterized by a loud systolic murmur along the left sternal border, a single loud second heart sound, and right ventricular prominence. Chronic disease leads to clubbing and retinal engorgement. Tricuspid atresia presents with tachypnea, a regurgitant murmur from an associated ventricular septal defect, a single second heart sound, and a prominent left ventricular impulse. Ebstein anomaly produces holosystolic tricuspid regurgitation murmurs and may include gallop rhythms. Transposition of the great arteries is notable for severe hypoxemia with a single loud second heart sound. Total anomalous pulmonary venous return presents with tachypnea, murmurs, fixed split second heart sound, and hepatomegaly. Truncus arteriosus causes bounding pulses, wide pulse pressure, a loud single second heart sound, and systolic and diastolic murmurs.
Essential Diagnostic Evaluation
Initial evaluation includes pulse oximetry, arterial blood gas analysis, complete blood count, glucose testing, and a full sepsis evaluation. Chest radiography assesses pulmonary blood flow, while electrocardiography evaluates chamber hypertrophy and axis deviation. Early cardiology consultation is essential.
Diagnostic Tests And Interpretation
Arterial blood gases show reduced oxygen saturation on room air. The hyperoxia test helps differentiate pulmonary disease from cyanotic congenital heart disease, with a PaO₂ less than 100 mm Hg after 100% oxygen strongly suggesting intracardiac shunting. Chronic cyanosis leads to erythrocytosis on complete blood count. Chest radiography may show decreased pulmonary blood flow in tetralogy of Fallot or tricuspid atresia and increased flow in transposition, total anomalous pulmonary venous return, and truncus arteriosus. Classic radiographic signs include the boot-shaped heart of tetralogy of Fallot, the egg-on-a-string appearance of transposition of the great arteries, and the snowman sign in supracardiac total anomalous pulmonary venous return. Electrocardiography demonstrates characteristic patterns of axis deviation and ventricular hypertrophy depending on the lesion.
Differential Diagnosis
The differential includes pulmonary causes such as pneumothorax, pulmonary hypertension, pneumonia, bronchiolitis, and diaphragmatic hernia; cardiac causes such as congestive heart failure and cardiogenic shock; infectious causes including sepsis; neurologic causes such as seizures; and metabolic or hematologic conditions including hypoglycemia, dehydration, polycythemia, and methemoglobinemia.
Initial Stabilization And Therapy
Management focuses on maintaining warmth, correcting hypoglycemia and acidosis, ensuring adequate oxygenation, establishing intravenous access, and preparing for airway support. Excessive oxygen should be avoided because high oxygen tension promotes ductal closure. Air filters should be placed on intravenous lines to prevent paradoxical emboli.
Emergency Department Management
Prostaglandin E1 infusion should be initiated in duct-dependent lesions to maintain or reopen the ductus arteriosus, typically at 0.05–0.1 μg/kg/min. Complications include apnea, bradycardia, hypotension, and seizures, so airway readiness is essential. Prostaglandin is ineffective in obstructed total anomalous pulmonary venous return, which may require extracorporeal support. Fluid resuscitation should be performed cautiously in 10 mL/kg increments. Hypercyanotic spells are managed with a calm environment, knee-chest positioning, supplemental oxygen if tolerated, and morphine. Severe cases may require bicarbonate, phenylephrine to increase systemic vascular resistance, or propranolol for beta-blockade. Circulatory collapse requires aggressive resuscitation with fluids, inotropes, and correction of acidosis.
Medications
Commonly used medications include prostaglandin E1, morphine, phenylephrine, propranolol, dopamine, dobutamine, milrinone, antibiotics such as ampicillin and gentamicin, antipyretics, and sodium bicarbonate when indicated.
Disposition And Follow-Up
All newborns with suspected cyanotic congenital heart disease require admission to a pediatric intensive care unit. Admission is also indicated for acute worsening of cyanosis, heart failure, or respiratory infection. Discharge decisions should be made in consultation with pediatric cardiology and reserved for carefully selected, stable patients with ensured close follow-up.
Referral And Follow-Up Recommendations
Care should be coordinated among primary care providers, pediatric cardiologists, and cardiothoracic surgeons. Clear follow-up plans and return precautions are essential, as physiologic stress can rapidly worsen clinical status.
Clinical Pearls And Pitfalls
Visible cyanosis requires significant levels of deoxygenated hemoglobin. Duct-dependent lesions often present at two to three weeks of age with sudden cyanosis or cardiovascular collapse. Prostaglandin E1 can be lifesaving but requires close monitoring for apnea and hypotension.
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Emergency And Acute Medicine – Conjunctivitis
Description
Conjunctivitis is inflammation of the conjunctiva caused by a wide range of infectious and noninfectious etiologies. It is commonly referred to as “pink eye” and is a frequent reason for emergency and primary care visits.
Etiology
Bacterial causes include Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae. Gonococcal conjunctivitis is an ophthalmic emergency because of rapid corneal invasion and risk of blindness. Chlamydial conjunctivitis occurs through autoinoculation from genital secretions and is common in newborns. Viral conjunctivitis is most often due to adenovirus, including epidemic keratoconjunctivitis, and is frequently associated with upper respiratory infections. Herpes simplex virus may cause recurrent ocular disease, and corticosteroids are contraindicated. Allergic conjunctivitis is associated with atopy and nasal symptoms. Contact-related conjunctivitis may result from chemical irritation or hypersensitivity, with Pseudomonas species commonly implicated in contact lens users.
Clinical Features
Patients typically present with red eye, burning or gritty sensation, foreign body sensation, discharge, eyelid sticking on awakening, chemosis, eyelid edema, tearing, and itching. Bacterial conjunctivitis produces mucopurulent discharge. Gonococcal infection causes hyperacute, copious purulent discharge within 12 hours, severe chemosis, and eyelid swelling. Chlamydial conjunctivitis presents with lacrimation, mucopurulent discharge, photophobia, and frequent concomitant genital infection. Viral conjunctivitis often causes watery discharge, preauricular lymphadenopathy, and spreads to the other eye within 24–48 hours. Epidemic keratoconjunctivitis may reduce vision due to corneal infiltrates. Allergic conjunctivitis is marked by intense itching and watery discharge. Contact-related disease may present acutely with corneal ulceration but normal visual acuity and intraocular pressure.
Essential Evaluation
History should assess onset, exposures, sick contacts, sexual history, medication or cosmetic use, and systemic disease. A careful eye examination including slit-lamp evaluation and fluorescein staining is essential.
Diagnostic Tests And Interpretation
Routine cultures are not required in uncomplicated cases. Indications for bacteriologic studies include ophthalmia neonatorum, suspected gonococcal infection, immunocompromised patients, systemic illness, or lack of improvement within 48–72 hours. Identification of gram-negative intracellular diplococci on Gram stain is sufficient to initiate gonococcal therapy. Serologic testing such as rapid plasma reagin may be indicated when sexually transmitted infection is suspected.
Differential Diagnosis
Conditions to exclude include acute angle-closure glaucoma, anterior uveitis, keratitis, corneal abrasion, foreign body, dry eye, scleritis, episcleritis, nasolacrimal obstruction, and subconjunctival hemorrhage.
Initial Management
Empiric treatment with broad-spectrum topical antibiotics is appropriate for most suspected bacterial cases. Systemic therapy is mandatory for gonococcal, chlamydial, meningococcal infections, ophthalmia neonatorum, and severe disease. Herpetic infections require ophthalmology consultation.
Emergency Department Management
Discharge should be gently cleaned from the eye, and contact lens wearers must discontinue lens use and discard contaminated lenses. Emphasize hand hygiene and avoidance of shared towels or cosmetics. Warm soaks help remove debris. Bacterial conjunctivitis is treated with topical antibiotics continued for 48 hours after symptom resolution. Failure to improve within 48–72 hours warrants culture and reevaluation. Viral conjunctivitis requires supportive care only. Allergic conjunctivitis is treated with antihistamine or mast cell stabilizer drops, artificial tears, and avoidance of triggers. Noninfectious irritation is managed with lubricating drops or ointments.
Medications
All contact lens wearers require antipseudomonal coverage. Common topical agents include ciprofloxacin, gentamicin, tobramycin, erythromycin, and sulfacetamide. Chlamydial infection requires systemic therapy with doxycycline or erythromycin. Gonococcal conjunctivitis requires parenteral ceftriaxone plus topical antibiotics. Viral conjunctivitis is managed with artificial tears and topical antihistamines. Herpetic disease is treated with antiviral ophthalmic agents. Allergic conjunctivitis responds to antihistamine, mast cell stabilizer, or NSAID drops.
Pediatric Considerations
In neonates, conjunctivitis often reflects systemic infection acquired during birth. Chemical conjunctivitis occurs within the first 36 hours of life. Ophthalmia neonatorum occurs within the first four weeks and is commonly caused by gonococcal, chlamydial, or herpetic infection. Ointments are preferred over drops in infants.
Disposition And Follow-Up
Hospital admission is required for known or suspected gonococcal infection at any age. Most patients can be discharged with close follow-up.
Follow-Up Recommendations
Ophthalmology follow-up is recommended for all bacterial conjunctivitis cases and is mandatory for epidemic keratoconjunctivitis or severe disease.
Key Clinical Insights And Common Errors
Conjunctivitis is highly contagious, particularly viral forms and epidemic keratoconjunctivitis, which may remain transmissible for up to two weeks. Strict hand hygiene and meticulous disinfection of examination equipment are essential to prevent spread. Corticosteroids should be used with extreme caution, as they can exacerbate unrecognized herpes simplex infection and worsen outcomes.
Description
Conjunctivitis is inflammation of the conjunctiva caused by a wide range of infectious and noninfectious etiologies. It is commonly referred to as “pink eye” and is a frequent reason for emergency and primary care visits.
Etiology
Bacterial causes include Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae. Gonococcal conjunctivitis is an ophthalmic emergency because of rapid corneal invasion and risk of blindness. Chlamydial conjunctivitis occurs through autoinoculation from genital secretions and is common in newborns. Viral conjunctivitis is most often due to adenovirus, including epidemic keratoconjunctivitis, and is frequently associated with upper respiratory infections. Herpes simplex virus may cause recurrent ocular disease, and corticosteroids are contraindicated. Allergic conjunctivitis is associated with atopy and nasal symptoms. Contact-related conjunctivitis may result from chemical irritation or hypersensitivity, with Pseudomonas species commonly implicated in contact lens users.
Clinical Features
Patients typically present with red eye, burning or gritty sensation, foreign body sensation, discharge, eyelid sticking on awakening, chemosis, eyelid edema, tearing, and itching. Bacterial conjunctivitis produces mucopurulent discharge. Gonococcal infection causes hyperacute, copious purulent discharge within 12 hours, severe chemosis, and eyelid swelling. Chlamydial conjunctivitis presents with lacrimation, mucopurulent discharge, photophobia, and frequent concomitant genital infection. Viral conjunctivitis often causes watery discharge, preauricular lymphadenopathy, and spreads to the other eye within 24–48 hours. Epidemic keratoconjunctivitis may reduce vision due to corneal infiltrates. Allergic conjunctivitis is marked by intense itching and watery discharge. Contact-related disease may present acutely with corneal ulceration but normal visual acuity and intraocular pressure.
Essential Evaluation
History should assess onset, exposures, sick contacts, sexual history, medication or cosmetic use, and systemic disease. A careful eye examination including slit-lamp evaluation and fluorescein staining is essential.
Diagnostic Tests And Interpretation
Routine cultures are not required in uncomplicated cases. Indications for bacteriologic studies include ophthalmia neonatorum, suspected gonococcal infection, immunocompromised patients, systemic illness, or lack of improvement within 48–72 hours. Identification of gram-negative intracellular diplococci on Gram stain is sufficient to initiate gonococcal therapy. Serologic testing such as rapid plasma reagin may be indicated when sexually transmitted infection is suspected.
Differential Diagnosis
Conditions to exclude include acute angle-closure glaucoma, anterior uveitis, keratitis, corneal abrasion, foreign body, dry eye, scleritis, episcleritis, nasolacrimal obstruction, and subconjunctival hemorrhage.
Initial Management
Empiric treatment with broad-spectrum topical antibiotics is appropriate for most suspected bacterial cases. Systemic therapy is mandatory for gonococcal, chlamydial, meningococcal infections, ophthalmia neonatorum, and severe disease. Herpetic infections require ophthalmology consultation.
Emergency Department Management
Discharge should be gently cleaned from the eye, and contact lens wearers must discontinue lens use and discard contaminated lenses. Emphasize hand hygiene and avoidance of shared towels or cosmetics. Warm soaks help remove debris. Bacterial conjunctivitis is treated with topical antibiotics continued for 48 hours after symptom resolution. Failure to improve within 48–72 hours warrants culture and reevaluation. Viral conjunctivitis requires supportive care only. Allergic conjunctivitis is treated with antihistamine or mast cell stabilizer drops, artificial tears, and avoidance of triggers. Noninfectious irritation is managed with lubricating drops or ointments.
Medications
All contact lens wearers require antipseudomonal coverage. Common topical agents include ciprofloxacin, gentamicin, tobramycin, erythromycin, and sulfacetamide. Chlamydial infection requires systemic therapy with doxycycline or erythromycin. Gonococcal conjunctivitis requires parenteral ceftriaxone plus topical antibiotics. Viral conjunctivitis is managed with artificial tears and topical antihistamines. Herpetic disease is treated with antiviral ophthalmic agents. Allergic conjunctivitis responds to antihistamine, mast cell stabilizer, or NSAID drops.
Pediatric Considerations
In neonates, conjunctivitis often reflects systemic infection acquired during birth. Chemical conjunctivitis occurs within the first 36 hours of life. Ophthalmia neonatorum occurs within the first four weeks and is commonly caused by gonococcal, chlamydial, or herpetic infection. Ointments are preferred over drops in infants.
Disposition And Follow-Up
Hospital admission is required for known or suspected gonococcal infection at any age. Most patients can be discharged with close follow-up.
Follow-Up Recommendations
Ophthalmology follow-up is recommended for all bacterial conjunctivitis cases and is mandatory for epidemic keratoconjunctivitis or severe disease.
Key Clinical Insights And Common Errors
Conjunctivitis is highly contagious, particularly viral forms and epidemic keratoconjunctivitis, which may remain transmissible for up to two weeks. Strict hand hygiene and meticulous disinfection of examination equipment are essential to prevent spread. Corticosteroids should be used with extreme caution, as they can exacerbate unrecognized herpes simplex infection and worsen outcomes.
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Emergency And Acute Medicine – Constipation
Description
Constipation is defined clinically using the Rome criteria, which require at least two of the following symptoms for a minimum of three months: straining during more than 25% of bowel movements, hard stools in more than 25% of bowel movements, a sensation of incomplete evacuation in more than 25% of bowel movements, or two or fewer bowel movements per week.
Pediatric Considerations
Defecation disorders account for approximately 3% of pediatric outpatient visits. Children with cerebral palsy are at increased risk of functional constipation. Pediatric constipation may be classified into anatomic causes, colonic neuromuscular disease such as Hirschsprung disease, and defecation disorders including functional constipation and nonretentive fecal soiling. Functional fecal retention is the most common cause and is often related to fear or pain with defecation, leading to irritability, abdominal cramping, decreased appetite, and early satiety.
Etiology
Metabolic and endocrine causes include diabetes, uremia, porphyria, hypothyroidism, hypercalcemia, pheochromocytoma, panhypopituitarism, and pregnancy. Functional and idiopathic causes include irritable bowel syndrome, diverticular disease, colonic inertia, megacolon or megarectum, pelvic intussusception, nonrelaxing puborectalis, rectocele, posthysterectomy syndrome, and descending perineum. Pharmacologic causes include analgesics, antacids, anticholinergics, anticonvulsants, antidepressants, antihypertensives, calcium channel blockers, diuretics, iron supplements, laxative abuse, monoamine oxidase inhibitors, opioids, paralytics, parasympatholytics, phenothiazines, and psychotropic medications. Neurologic causes include Parkinson disease, multiple sclerosis, cerebrovascular accidents, spinal cord injury, Hirschsprung disease, Chagas disease, neurofibromatosis, and autonomic neuropathy. Mechanical obstruction may result from neoplasm, stricture, hernia, or volvulus.
Clinical Features
Constipation represents a symptom rather than a primary diagnosis. Patients may report infrequent bowel movements, passage of hard stools, straining, abdominal distention or bloating, and difficulty with defecation. Liquid stool may pass around impacted feces, presenting as paradoxical diarrhea. Digital rectal examination may reveal firm stool or an empty rectal vault. History should include age at symptom onset, diet, exercise habits, stool characteristics, medication use, prior surgeries, use of laxatives or enemas, and symptoms suggestive of pelvic floor dysfunction. Physical examination may demonstrate abdominal masses from fecal loading and should include a focused rectal examination assessing sphincter tone, relaxation, stool consistency, and the presence of rectocele or cystocele.
Essential Evaluation
A detailed medical, surgical, and psychiatric history with careful physical examination is central to evaluation. The anorectal examination should assess for fissures, stenosis, neoplasm, sphincter tone abnormalities, perineal descent, tenderness, or spasm.
Diagnostic Tests And Interpretation
Laboratory testing is reserved for suspected metabolic or endocrine causes and may include a complete blood count, electrolytes, calcium, and thyroid function tests. Imaging is rarely required unless obstruction or other pathology is suspected. Abdominal radiographs may show fecal loading or colonic dilation. Computed tomography is indicated in elderly patients with abdominal pain or fever to exclude perforation. Contrast enemas may identify diverticulosis, megacolon, megarectum, Hirschsprung disease, or strictures.
Differential Diagnosis
The differential diagnosis includes bowel obstruction and secondary causes listed under etiology.
Initial Management
Intravenous access should be established in patients with significant abdominal pain or dehydration, and intravenous fluids administered as indicated.
Emergency Department Management
Initial treatment focuses on colonic evacuation using enemas, suppositories, or manual disimpaction when necessary. A long-term bowel regimen should be initiated, including increased noncaffeinated fluid intake, increased dietary fiber, regular exercise, stool softeners, and discontinuation or adjustment of constipating medications when possible.
Medications
Rectal therapies include sodium phosphate, mineral oil, and tap water enemas, as well as glycerin suppositories. Fiber supplements such as methylcellulose and psyllium may be used. Osmotic laxatives include lactulose, polyethylene glycol, and magnesium hydroxide. Stimulant laxatives include bisacodyl and senna. Stool softeners include docusate sodium and oral mineral oil.
Disposition And Follow-Up
Hospital admission is indicated for patients with severe abdominal pain, vomiting, bowel obstruction, peritonitis, or those unable to be adequately treated in the emergency department or home setting, particularly elderly or neurologically impaired patients. Patients may be discharged if pain free, adequately relieved of fecal burden, and without comorbid conditions requiring admission.
Follow-Up Recommendations
Primary care or gastroenterology follow-up is recommended for patients with chronic or recurrent constipation.
Practice Points And Common Errors
Patients should be counseled on dietary, fluid, and lifestyle modifications to reduce recurrence. A comprehensive history and physical examination are essential to avoid missing serious medical or surgical causes of constipation. Failure to consider secondary etiologies or medication-related causes is a common source of mismanagement.
Description
Constipation is defined clinically using the Rome criteria, which require at least two of the following symptoms for a minimum of three months: straining during more than 25% of bowel movements, hard stools in more than 25% of bowel movements, a sensation of incomplete evacuation in more than 25% of bowel movements, or two or fewer bowel movements per week.
Pediatric Considerations
Defecation disorders account for approximately 3% of pediatric outpatient visits. Children with cerebral palsy are at increased risk of functional constipation. Pediatric constipation may be classified into anatomic causes, colonic neuromuscular disease such as Hirschsprung disease, and defecation disorders including functional constipation and nonretentive fecal soiling. Functional fecal retention is the most common cause and is often related to fear or pain with defecation, leading to irritability, abdominal cramping, decreased appetite, and early satiety.
Etiology
Metabolic and endocrine causes include diabetes, uremia, porphyria, hypothyroidism, hypercalcemia, pheochromocytoma, panhypopituitarism, and pregnancy. Functional and idiopathic causes include irritable bowel syndrome, diverticular disease, colonic inertia, megacolon or megarectum, pelvic intussusception, nonrelaxing puborectalis, rectocele, posthysterectomy syndrome, and descending perineum. Pharmacologic causes include analgesics, antacids, anticholinergics, anticonvulsants, antidepressants, antihypertensives, calcium channel blockers, diuretics, iron supplements, laxative abuse, monoamine oxidase inhibitors, opioids, paralytics, parasympatholytics, phenothiazines, and psychotropic medications. Neurologic causes include Parkinson disease, multiple sclerosis, cerebrovascular accidents, spinal cord injury, Hirschsprung disease, Chagas disease, neurofibromatosis, and autonomic neuropathy. Mechanical obstruction may result from neoplasm, stricture, hernia, or volvulus.
Clinical Features
Constipation represents a symptom rather than a primary diagnosis. Patients may report infrequent bowel movements, passage of hard stools, straining, abdominal distention or bloating, and difficulty with defecation. Liquid stool may pass around impacted feces, presenting as paradoxical diarrhea. Digital rectal examination may reveal firm stool or an empty rectal vault. History should include age at symptom onset, diet, exercise habits, stool characteristics, medication use, prior surgeries, use of laxatives or enemas, and symptoms suggestive of pelvic floor dysfunction. Physical examination may demonstrate abdominal masses from fecal loading and should include a focused rectal examination assessing sphincter tone, relaxation, stool consistency, and the presence of rectocele or cystocele.
Essential Evaluation
A detailed medical, surgical, and psychiatric history with careful physical examination is central to evaluation. The anorectal examination should assess for fissures, stenosis, neoplasm, sphincter tone abnormalities, perineal descent, tenderness, or spasm.
Diagnostic Tests And Interpretation
Laboratory testing is reserved for suspected metabolic or endocrine causes and may include a complete blood count, electrolytes, calcium, and thyroid function tests. Imaging is rarely required unless obstruction or other pathology is suspected. Abdominal radiographs may show fecal loading or colonic dilation. Computed tomography is indicated in elderly patients with abdominal pain or fever to exclude perforation. Contrast enemas may identify diverticulosis, megacolon, megarectum, Hirschsprung disease, or strictures.
Differential Diagnosis
The differential diagnosis includes bowel obstruction and secondary causes listed under etiology.
Initial Management
Intravenous access should be established in patients with significant abdominal pain or dehydration, and intravenous fluids administered as indicated.
Emergency Department Management
Initial treatment focuses on colonic evacuation using enemas, suppositories, or manual disimpaction when necessary. A long-term bowel regimen should be initiated, including increased noncaffeinated fluid intake, increased dietary fiber, regular exercise, stool softeners, and discontinuation or adjustment of constipating medications when possible.
Medications
Rectal therapies include sodium phosphate, mineral oil, and tap water enemas, as well as glycerin suppositories. Fiber supplements such as methylcellulose and psyllium may be used. Osmotic laxatives include lactulose, polyethylene glycol, and magnesium hydroxide. Stimulant laxatives include bisacodyl and senna. Stool softeners include docusate sodium and oral mineral oil.
Disposition And Follow-Up
Hospital admission is indicated for patients with severe abdominal pain, vomiting, bowel obstruction, peritonitis, or those unable to be adequately treated in the emergency department or home setting, particularly elderly or neurologically impaired patients. Patients may be discharged if pain free, adequately relieved of fecal burden, and without comorbid conditions requiring admission.
Follow-Up Recommendations
Primary care or gastroenterology follow-up is recommended for patients with chronic or recurrent constipation.
Practice Points And Common Errors
Patients should be counseled on dietary, fluid, and lifestyle modifications to reduce recurrence. A comprehensive history and physical examination are essential to avoid missing serious medical or surgical causes of constipation. Failure to consider secondary etiologies or medication-related causes is a common source of mismanagement.
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Emergency and Acute Medicine – Contact Dermatitis
Overview and Basic Description
Contact dermatitis is an inflammatory skin condition caused by direct exposure to external substances and is broadly classified into irritant, allergic, and photocontact forms. Irritant contact dermatitis is the most common type and presents as an immediate eczematous eruption resulting from a superficial inflammatory process that primarily involves the epidermis. In this condition, the triggering substance directly damages the skin, producing a non-immunologic inflammatory reaction manifested by erythema, dryness, cracking, or fissuring. It typically occurs due to repeated exposure to mild irritants such as water, soaps, heat, or friction. Symptoms often develop gradually and include itching or burning sensations, with lesions that have indistinct borders. The hands are most commonly affected, and the skin may appear dry, red, rough, and occasionally vesiculated or fissured. Frequent irritants include cement, hair dyes, wet diapers, rubber gloves, shampoos, and repeated handwashing.
Allergic contact dermatitis is a delayed type IV hypersensitivity reaction that requires prior sensitization. In this form, exposure to an allergen triggers an immune-mediated response, leading to localized edema, erythema, vesicles, pruritus, or burning. Lesions usually correspond exactly to the area of contact, such as beneath a watchband. In previously sensitized individuals, symptoms typically appear within 12–48 hours, whereas primary exposure may require 14–21 days before clinical manifestations develop. Common allergens include nickel, gold, neomycin, bacitracin, preservatives, fragrances, dyes, and poison ivy.
Photocontact dermatitis occurs when an otherwise harmless substance on the skin interacts with ultraviolet light, producing an inflammatory reaction. This type of dermatitis does not occur without sunlight exposure and is commonly associated with shaving lotions, sunscreens, sulfa-containing ointments, and perfumes.
Pediatric Considerations
Allergic contact dermatitis is less common in children, particularly infants, compared with adults. In pediatric patients, the major sources of contact allergy include metals, shoes, preservatives, and fragrances found in cosmetics, topical medications, and plants. Diaper dermatitis represents the prototype of irritant contact dermatitis in children and results from prolonged exposure to urine and feces. Circumoral dermatitis is seen in infants and young children and may be triggered by certain foods through either irritant or allergic mechanisms.
Etiology and Risk Factors
Irritant contact dermatitis accounts for approximately 80% of all cases and may be caused by soaps, solvents, chemicals, certain foods, urine, feces, diapers, and continuous or repeated exposure to moisture such as frequent handwashing. Physical irritants including coarse paper, glass fibers, and wool may also provoke dermatitis. Shoe dermatitis is a common presentation and is typically identified by lesions limited to the distal dorsal surface of the foot while sparing the interdigital spaces.
Allergic contact dermatitis may result from exposure to plants such as poison ivy, poison oak, and poison sumac, collectively referred to as rhus dermatitis, which is the most common form of allergic contact dermatitis in North America. The reaction is caused by oleoresin urushiol and may occur through direct contact with the plant or indirectly via contaminated pets, clothing, or smoke from burning leaves. Lesions may appear up to three days after exposure in sensitized individuals and may persist for as long as three weeks. The fluid contained within vesicles is not contagious and does not produce new lesions; however, urushiol oil on clothing or animal fur remains contagious until removed. Other allergic causes include cement, which may result in severe alkali burns with prolonged exposure, metals—especially nickel—solvents, epoxy, chemicals in rubber or leather, lotions, cosmetics, topical medications such as neomycin, hydrocortisone, benzocaine, and parabens, and certain foods. The ability to respond to specific antigens is likely influenced by genetic factors.
Photodermatitis represents an inflammatory reaction caused by exposure to an irritant, often plant sap, in combination with sunlight and typically does not occur in the absence of ultraviolet exposure.
Clinical Features and Diagnostic Evaluation
Assessment begins with a detailed history focusing on the date of onset, time course, pattern and distribution of lesions, relationship to occupational or work exposures, presence or absence of pruritus, mucosal involvement, and recent exposure to new products such as soaps, lotions, cosmetics, foods, medications, or jewelry. Physical examination should emphasize the morphology and distribution of the rash. Acute lesions are characterized by erythema and pruritus and may be accompanied by edema, papules, vesicles, bullae, serous discharge, or crusting. Subacute lesions demonstrate less prominent vesiculation, while chronic lesions may present with scaling, lichenification, pigmentation changes, or fissuring, often with little or no vesiculation and a characteristic distribution pattern.
There are no specific laboratory studies or imaging modalities that are routinely helpful in the emergency department for diagnosing contact dermatitis. Patch testing is generally not performed acutely and should be arranged through referral to an allergist or immunologist. When a fungal infection is suspected, a Wood lamp examination may be used to assess for fluorescence suggestive of tinea.
Differential Diagnosis
Conditions that may mimic contact dermatitis include atopic dermatitis, often associated with a family history of atopy; seborrheic dermatitis with greasy, scaly lesions; nummular dermatitis characterized by coin-shaped plaques; and intertrigo involving areas where skin surfaces are in apposition such as the axillae and groin. Other considerations include infectious eczematous dermatitis with secondary bacterial infection, usually due to Staphylococcus aureus; cellulitis presenting as a warm, painful, blanching lesion; impetigo with yellow crusting; scabies with intensely pruritic interdigital tracks; psoriasis with well-demarcated silvery plaques affecting extensor surfaces, scalp, or genital region; herpes simplex infection with painful grouped vesicles; herpes zoster following a dermatomal distribution; bullous pemphigoid with diffuse bullae; tinea with maximal involvement at the margins and Wood lamp fluorescence; pityriasis alba with asymptomatic hypopigmented lesions; urticaria with pruritic wheals and surrounding erythema; acrodermatitis enteropathica due to zinc deficiency, associated with failure to thrive, diarrhea, and alopecia; dyshidrotic eczema; drug-induced rashes; Stevens–Johnson syndrome; toxic epidermal necrolysis; and erythema nodosum.
Management in the Emergency Department
Initial stabilization is rarely required unless there is significant concomitant pathology. Treatment is primarily symptomatic and includes gentle cleansing of the affected area with mild soap and water, removal and avoidance of the offending agent, and washing of contaminated clothing. Cool, wet compresses are particularly effective during the acute blistering phase. Antipruritic therapy may include topical agents such as calamine lotion and topical corticosteroids, although corticosteroids do not penetrate intact blisters and benzocaine- or hydrocortisone-containing products should be avoided due to the risk of further sensitization. Systemic therapy may include antihistamines and corticosteroids when indicated. Aluminum acetate (Burrow solution) may be applied to weeping surfaces.
For irritant contact dermatitis, management focuses on removal of the offending agent, thorough washing with soap and warm water, reduction of wet–dry cycles such as frequent handwashing, and use of alcohol-based cleansers to decrease repetitive trauma. Bland emollients are recommended, and topical corticosteroids of medium to high potency, preferably in ointment form, may be used for severe cases on the hands twice daily for several weeks.
Allergic contact dermatitis is treated with topical corticosteroids applied twice daily for two to three weeks, with potency adjusted by location: low potency for the face, medium potency for the arms, legs, and trunk, and high potency for the hands and feet. Oral corticosteroids may be required for severe reactions. In rhus dermatitis, additional measures include washing all clothing and pets that may have come into contact with the plant, as the oil remains contagious. Oatmeal baths may provide symptomatic relief, and aseptic aspiration of tense bullae can reduce discomfort. Severe reactions involving more than 10% of total body surface area require systemic corticosteroids for two to three weeks with a gradual taper, as premature discontinuation may result in rapid rebound of symptoms. Shoe dermatitis management includes wearing open-toe, canvas, or vinyl shoes, controlling perspiration through frequent sock changes, and using absorbent powders. Diaper dermatitis management includes topical zinc oxide, petrolatum, or aquaphor and frequent diaper changes after each soiling.
Medications
Systemic therapy may include H1-receptor antagonists from both first- and second-generation antihistamines. Cetirizine may be given at 5–10 mg orally daily in adults and children older than six years, with pediatric dosing of 2.5 mg once or twice daily for ages two to six years. Diphenhydramine may be administered at 25–50 mg intravenously, intramuscularly, or orally every six hours as needed, with pediatric dosing of 5 mg/kg per 24 hours divided every six hours. Fexofenadine may be used at 60 mg orally twice daily or 180 mg once daily in adults, with pediatric dosing of 30 mg twice daily for children aged six to twelve years. Hydroxyzine may be given at 25–50 mg orally or intramuscularly up to four times daily, with weight-based pediatric dosing. Loratadine may be administered at 10 mg orally twice daily. For refractory pruritus, doxepin 75 mg orally daily may be effective.
Systemic corticosteroid therapy includes prednisone at 40–60 mg orally daily in adults, with pediatric dosing of 1–2 mg/kg per day to a maximum of 80 mg, administered once or divided twice daily. Topical therapies include aluminum acetate solution applied for 20 minutes three times daily until the skin is dry, calamine lotion every six hours as needed, and topical corticosteroids such as triamcinolone ointment, cream, or lotion at concentrations of 0.025% or 0.1% applied three to four times daily. Topical corticosteroids should not be applied to the face or eyelids. First-line therapy consists of topical corticosteroids and oral antihistamines, while oral corticosteroids are considered second-line treatment.
Disposition and Follow-Up
Hospital admission is rarely indicated and is generally reserved for patients with severe systemic reactions or significant secondary infections. Patients may be discharged once symptomatic relief is achieved and adequate outpatient follow-up is arranged. Follow-up with a primary care physician is recommended within two to three days for reassessment. Patients should be instructed to return to the emergency department if they develop facial swelling, difficulty breathing, or mucosal involvement that limits oral intake.
Clinical Pearls and Pitfalls
Effective management requires prompt removal of the offending agent. Clinicians should remain vigilant for progression to systemic anaphylaxis, particularly in cases involving latex exposure, and should monitor for concurrent bacterial infections. In rhus dermatitis, lesions are no longer contagious after washing with soap and water; however, all clothing and animals that may have been exposed must be thoroughly cleaned, as the oil remains contagious until removed.
Overview and Basic Description
Contact dermatitis is an inflammatory skin condition caused by direct exposure to external substances and is broadly classified into irritant, allergic, and photocontact forms. Irritant contact dermatitis is the most common type and presents as an immediate eczematous eruption resulting from a superficial inflammatory process that primarily involves the epidermis. In this condition, the triggering substance directly damages the skin, producing a non-immunologic inflammatory reaction manifested by erythema, dryness, cracking, or fissuring. It typically occurs due to repeated exposure to mild irritants such as water, soaps, heat, or friction. Symptoms often develop gradually and include itching or burning sensations, with lesions that have indistinct borders. The hands are most commonly affected, and the skin may appear dry, red, rough, and occasionally vesiculated or fissured. Frequent irritants include cement, hair dyes, wet diapers, rubber gloves, shampoos, and repeated handwashing.
Allergic contact dermatitis is a delayed type IV hypersensitivity reaction that requires prior sensitization. In this form, exposure to an allergen triggers an immune-mediated response, leading to localized edema, erythema, vesicles, pruritus, or burning. Lesions usually correspond exactly to the area of contact, such as beneath a watchband. In previously sensitized individuals, symptoms typically appear within 12–48 hours, whereas primary exposure may require 14–21 days before clinical manifestations develop. Common allergens include nickel, gold, neomycin, bacitracin, preservatives, fragrances, dyes, and poison ivy.
Photocontact dermatitis occurs when an otherwise harmless substance on the skin interacts with ultraviolet light, producing an inflammatory reaction. This type of dermatitis does not occur without sunlight exposure and is commonly associated with shaving lotions, sunscreens, sulfa-containing ointments, and perfumes.
Pediatric Considerations
Allergic contact dermatitis is less common in children, particularly infants, compared with adults. In pediatric patients, the major sources of contact allergy include metals, shoes, preservatives, and fragrances found in cosmetics, topical medications, and plants. Diaper dermatitis represents the prototype of irritant contact dermatitis in children and results from prolonged exposure to urine and feces. Circumoral dermatitis is seen in infants and young children and may be triggered by certain foods through either irritant or allergic mechanisms.
Etiology and Risk Factors
Irritant contact dermatitis accounts for approximately 80% of all cases and may be caused by soaps, solvents, chemicals, certain foods, urine, feces, diapers, and continuous or repeated exposure to moisture such as frequent handwashing. Physical irritants including coarse paper, glass fibers, and wool may also provoke dermatitis. Shoe dermatitis is a common presentation and is typically identified by lesions limited to the distal dorsal surface of the foot while sparing the interdigital spaces.
Allergic contact dermatitis may result from exposure to plants such as poison ivy, poison oak, and poison sumac, collectively referred to as rhus dermatitis, which is the most common form of allergic contact dermatitis in North America. The reaction is caused by oleoresin urushiol and may occur through direct contact with the plant or indirectly via contaminated pets, clothing, or smoke from burning leaves. Lesions may appear up to three days after exposure in sensitized individuals and may persist for as long as three weeks. The fluid contained within vesicles is not contagious and does not produce new lesions; however, urushiol oil on clothing or animal fur remains contagious until removed. Other allergic causes include cement, which may result in severe alkali burns with prolonged exposure, metals—especially nickel—solvents, epoxy, chemicals in rubber or leather, lotions, cosmetics, topical medications such as neomycin, hydrocortisone, benzocaine, and parabens, and certain foods. The ability to respond to specific antigens is likely influenced by genetic factors.
Photodermatitis represents an inflammatory reaction caused by exposure to an irritant, often plant sap, in combination with sunlight and typically does not occur in the absence of ultraviolet exposure.
Clinical Features and Diagnostic Evaluation
Assessment begins with a detailed history focusing on the date of onset, time course, pattern and distribution of lesions, relationship to occupational or work exposures, presence or absence of pruritus, mucosal involvement, and recent exposure to new products such as soaps, lotions, cosmetics, foods, medications, or jewelry. Physical examination should emphasize the morphology and distribution of the rash. Acute lesions are characterized by erythema and pruritus and may be accompanied by edema, papules, vesicles, bullae, serous discharge, or crusting. Subacute lesions demonstrate less prominent vesiculation, while chronic lesions may present with scaling, lichenification, pigmentation changes, or fissuring, often with little or no vesiculation and a characteristic distribution pattern.
There are no specific laboratory studies or imaging modalities that are routinely helpful in the emergency department for diagnosing contact dermatitis. Patch testing is generally not performed acutely and should be arranged through referral to an allergist or immunologist. When a fungal infection is suspected, a Wood lamp examination may be used to assess for fluorescence suggestive of tinea.
Differential Diagnosis
Conditions that may mimic contact dermatitis include atopic dermatitis, often associated with a family history of atopy; seborrheic dermatitis with greasy, scaly lesions; nummular dermatitis characterized by coin-shaped plaques; and intertrigo involving areas where skin surfaces are in apposition such as the axillae and groin. Other considerations include infectious eczematous dermatitis with secondary bacterial infection, usually due to Staphylococcus aureus; cellulitis presenting as a warm, painful, blanching lesion; impetigo with yellow crusting; scabies with intensely pruritic interdigital tracks; psoriasis with well-demarcated silvery plaques affecting extensor surfaces, scalp, or genital region; herpes simplex infection with painful grouped vesicles; herpes zoster following a dermatomal distribution; bullous pemphigoid with diffuse bullae; tinea with maximal involvement at the margins and Wood lamp fluorescence; pityriasis alba with asymptomatic hypopigmented lesions; urticaria with pruritic wheals and surrounding erythema; acrodermatitis enteropathica due to zinc deficiency, associated with failure to thrive, diarrhea, and alopecia; dyshidrotic eczema; drug-induced rashes; Stevens–Johnson syndrome; toxic epidermal necrolysis; and erythema nodosum.
Management in the Emergency Department
Initial stabilization is rarely required unless there is significant concomitant pathology. Treatment is primarily symptomatic and includes gentle cleansing of the affected area with mild soap and water, removal and avoidance of the offending agent, and washing of contaminated clothing. Cool, wet compresses are particularly effective during the acute blistering phase. Antipruritic therapy may include topical agents such as calamine lotion and topical corticosteroids, although corticosteroids do not penetrate intact blisters and benzocaine- or hydrocortisone-containing products should be avoided due to the risk of further sensitization. Systemic therapy may include antihistamines and corticosteroids when indicated. Aluminum acetate (Burrow solution) may be applied to weeping surfaces.
For irritant contact dermatitis, management focuses on removal of the offending agent, thorough washing with soap and warm water, reduction of wet–dry cycles such as frequent handwashing, and use of alcohol-based cleansers to decrease repetitive trauma. Bland emollients are recommended, and topical corticosteroids of medium to high potency, preferably in ointment form, may be used for severe cases on the hands twice daily for several weeks.
Allergic contact dermatitis is treated with topical corticosteroids applied twice daily for two to three weeks, with potency adjusted by location: low potency for the face, medium potency for the arms, legs, and trunk, and high potency for the hands and feet. Oral corticosteroids may be required for severe reactions. In rhus dermatitis, additional measures include washing all clothing and pets that may have come into contact with the plant, as the oil remains contagious. Oatmeal baths may provide symptomatic relief, and aseptic aspiration of tense bullae can reduce discomfort. Severe reactions involving more than 10% of total body surface area require systemic corticosteroids for two to three weeks with a gradual taper, as premature discontinuation may result in rapid rebound of symptoms. Shoe dermatitis management includes wearing open-toe, canvas, or vinyl shoes, controlling perspiration through frequent sock changes, and using absorbent powders. Diaper dermatitis management includes topical zinc oxide, petrolatum, or aquaphor and frequent diaper changes after each soiling.
Medications
Systemic therapy may include H1-receptor antagonists from both first- and second-generation antihistamines. Cetirizine may be given at 5–10 mg orally daily in adults and children older than six years, with pediatric dosing of 2.5 mg once or twice daily for ages two to six years. Diphenhydramine may be administered at 25–50 mg intravenously, intramuscularly, or orally every six hours as needed, with pediatric dosing of 5 mg/kg per 24 hours divided every six hours. Fexofenadine may be used at 60 mg orally twice daily or 180 mg once daily in adults, with pediatric dosing of 30 mg twice daily for children aged six to twelve years. Hydroxyzine may be given at 25–50 mg orally or intramuscularly up to four times daily, with weight-based pediatric dosing. Loratadine may be administered at 10 mg orally twice daily. For refractory pruritus, doxepin 75 mg orally daily may be effective.
Systemic corticosteroid therapy includes prednisone at 40–60 mg orally daily in adults, with pediatric dosing of 1–2 mg/kg per day to a maximum of 80 mg, administered once or divided twice daily. Topical therapies include aluminum acetate solution applied for 20 minutes three times daily until the skin is dry, calamine lotion every six hours as needed, and topical corticosteroids such as triamcinolone ointment, cream, or lotion at concentrations of 0.025% or 0.1% applied three to four times daily. Topical corticosteroids should not be applied to the face or eyelids. First-line therapy consists of topical corticosteroids and oral antihistamines, while oral corticosteroids are considered second-line treatment.
Disposition and Follow-Up
Hospital admission is rarely indicated and is generally reserved for patients with severe systemic reactions or significant secondary infections. Patients may be discharged once symptomatic relief is achieved and adequate outpatient follow-up is arranged. Follow-up with a primary care physician is recommended within two to three days for reassessment. Patients should be instructed to return to the emergency department if they develop facial swelling, difficulty breathing, or mucosal involvement that limits oral intake.
Clinical Pearls and Pitfalls
Effective management requires prompt removal of the offending agent. Clinicians should remain vigilant for progression to systemic anaphylaxis, particularly in cases involving latex exposure, and should monitor for concurrent bacterial infections. In rhus dermatitis, lesions are no longer contagious after washing with soap and water; however, all clothing and animals that may have been exposed must be thoroughly cleaned, as the oil remains contagious until removed.
- Published on
Emergency and Acute Medicine – Cor Pulmonale
Definition and Pathophysiologic Overview
Cor pulmonale refers to right ventricular hypertrophy or dilation caused by elevated pulmonary artery pressure. Right ventricular hypertrophy resulting from primary left-sided heart disease or congenital cardiac abnormalities is not classified as cor pulmonale. The disorder may be acute or chronic, depending on the rapidity and duration of pulmonary hypertension and the adaptive capacity of the right ventricle.
Acute cor pulmonale is marked by sudden right ventricular dilation with thinning and stretching of the ventricular wall, caused by an abrupt increase in right ventricular afterload due to acute pulmonary hypertension. The most common cause is a massive pulmonary embolism. Chronic cor pulmonale develops from long-standing pulmonary hypertension and is characterized initially by right ventricular hypertrophy, followed by dilation and eventual right-sided heart failure. This chronic form most often results from persistent alveolar hypoxia and represents an adaptive response to sustained elevation in pulmonary vascular resistance.
The pulmonary circulation is normally a low-pressure, low-resistance system with thin-walled, distensible arteries. Mean pulmonary arterial pressure typically ranges from 12 to 15 mm Hg, while normal left atrial pressure is approximately 6 to 10 mm Hg, resulting in a small pressure gradient of 6 to 9 mm Hg to drive pulmonary blood flow. Pulmonary arterial pressure is determined by cardiac output, pulmonary venous pressure, and pulmonary vascular resistance. Pulmonary hypertension may arise from markedly increased cardiac output, left-to-right shunts due to congenital heart disease, or most commonly hypoxia. Hypoxic pulmonary vasoconstriction is an adaptive response to alveolar hypoxia that preserves ventilation–perfusion matching by increasing pulmonary arterial pressure to maintain flow through the pulmonary vascular bed. Pulmonary embolism produces a similar effect by increasing resistance to pulmonary blood flow, while increased blood viscosity or elevated intrathoracic pressure can further impair pulmonary circulation.
Pulmonary hypertension is categorized into five groups. Group 1 includes pulmonary arterial hypertension. Group 2 consists of pulmonary hypertension due to left-sided heart disease, in which associated right ventricular dysfunction is not considered cor pulmonale. Group 3 includes pulmonary hypertension due to lung disease and/or hypoxia. Group 4 encompasses chronic thromboembolic pulmonary hypertension. Group 5 includes pulmonary hypertension with unclear or multifactorial mechanisms.
Epidemiology
Approximately 86,000 deaths occur annually from chronic obstructive pulmonary disease, with associated right ventricular failure contributing significantly in many cases. Cor pulmonale accounts for 10–30% of heart failure admissions in the United States. Among patients older than 50 years with COPD, about half develop pulmonary hypertension and are therefore at risk for cor pulmonale. Disease progression is closely tied to the severity of the underlying pulmonary disorder, and once cor pulmonale develops, the estimated five-year survival rate is approximately 30%.
Etiology
Chronic hypoxia is the most frequent cause of cor pulmonale and may result from COPD, residence at high altitude, obstructive sleep apnea, or chest wall deformities such as kyphoscoliosis. Other causes include pulmonary embolism and interstitial lung diseases such as scleroderma, systemic lupus erythematosus, mixed connective tissue disease, sarcoidosis, pulmonary Langerhans cell histiocytosis, neurofibromatosis, lymphangioleiomyomatosis, and cystic fibrosis. Additional contributing factors include severe anemia, obesity, pulmonary veno-occlusive disease, pulmonary vascular obstruction from tumors or lymphadenopathy, increased blood viscosity as seen in polycythemia vera or leukemia, and elevated intrathoracic pressure due to mechanical ventilation with positive end-expiratory pressure. Idiopathic primary pulmonary hypertension is a less common cause.
Clinical Manifestations
Patients frequently present with exertional dyspnea, easy fatigability, weakness, and reduced exercise tolerance. Additional symptoms include exertional syncope, cough, hemoptysis, and exertional angina even in the absence of coronary artery disease. Anorexia, right upper quadrant discomfort, wheezing, hoarseness, and weight gain may occur as right-sided heart failure progresses. Signs of volume overload include hepatomegaly, ascites, and peripheral edema. In advanced disease, cardiogenic shock may develop, manifested by oliguria, cool extremities, and pulmonary edema resulting from interventricular septal displacement that impairs left ventricular diastolic filling.
History commonly reveals exercise intolerance, palpitations, chest pain, lightheadedness, syncope, and lower extremity swelling. Physical examination may show jugular venous distention with prominent A and V waves, increased chest diameter, crackles or wheezes on lung auscultation, and a left parasternal heave. Splitting of the second heart sound or murmurs related to pulmonary vasculature abnormalities may be present. A hepatojugular reflex, pulsatile liver, and pitting edema of the lower extremities are typical findings in advanced cases.
Diagnostic Evaluation
Pulse oximetry or arterial blood gas analysis typically demonstrates resting hypoxemia with arterial oxygen tensions of 40–60 mm Hg and resting carbon dioxide levels often between 40 and 70 mm Hg. Hematocrit is frequently elevated due to secondary polycythemia. Elevated B-type natriuretic peptide levels are sensitive for moderate to severe pulmonary hypertension and may independently predict mortality, although elevation alone is insufficient to establish the diagnosis of cor pulmonale. Other laboratory tests are generally of limited diagnostic value.
Chest radiography often reveals signs of pulmonary hypertension, including enlarged pulmonary arteries greater than 16–18 mm and an enlarged right ventricular silhouette. Although abnormalities are seen in more than 90% of patients, chest radiographs do not reliably indicate disease severity. Pleural effusions are not a feature of isolated cor pulmonale. Electrocardiography may demonstrate right-axis deviation, right bundle branch block, right ventricular hypertrophy with dominant R waves in leads V1 and V2, prominent S waves in leads V5 and V6, small R waves with deep S waves across the precordium, and right atrial enlargement with tall, peaked P waves consistent with P pulmonale. Acute cor pulmonale may show an S1Q3 pattern, transient hypoxia-related changes, and right precordial T-wave flattening.
Echocardiography is the preferred noninvasive diagnostic modality and may demonstrate right ventricular hypertrophy or dilation, tricuspid regurgitation, and Doppler-based estimation of pulmonary artery pressure and right ventricular ejection fraction. Chest computed tomography, ventilation–perfusion scanning, or pulmonary angiography are useful when acute cor pulmonale is suspected, particularly in cases of pulmonary embolism. Magnetic resonance imaging offers superior assessment of right ventricular size and function compared with echocardiography. Pulmonary function testing may reveal reduced diffusion capacity associated with pulmonary hypertension. Right-heart catheterization remains the most accurate method for assessing pulmonary vascular hemodynamics and provides precise measurements of pulmonary arterial and pulmonary capillary wedge pressures.
Differential Diagnosis
The differential diagnosis includes primary left-sided heart disease such as mitral stenosis, congenital heart disease including Eisenmenger syndrome with left-to-right shunting, hypothyroidism, and cirrhosis.
Management and Prehospital Care
Prehospital treatment is supportive and includes supplemental oxygen titrated to achieve arterial oxygen saturation of approximately 90%, establishment of intravenous access, continuous cardiac monitoring, and pulse oximetry. Bronchospasm related to underlying respiratory disease should be treated with beta-agonist nebulizers. Vasodilators and diuretics have no role in the prehospital setting. Patients with severe hypoxia may require endotracheal intubation.
Emergency Department Treatment
Management in the emergency department is directed at treating the underlying disease process and reducing pulmonary hypertension. Supplemental oxygen should be administered to raise arterial oxygen saturation to 90%, thereby reducing pulmonary vasoconstriction and right ventricular afterload while improving cardiac output and promoting diuresis. Careful monitoring of ventilation and carbon dioxide levels is essential, as hypercapnia may suppress respiratory drive and worsen acidosis. Diuretics such as furosemide may be used cautiously to reduce circulating blood volume and pulmonary artery pressure, with close attention to avoiding hypovolemia and electrolyte disturbances. Patients should be maintained on salt and fluid restriction. Digoxin has no role in the treatment of cor pulmonale.
Bronchodilator therapy is particularly beneficial in patients with COPD, as it reduces ventricular afterload and improves airflow. Selective beta-adrenergic agents such as subcutaneous terbutaline may be administered, and theophylline may be considered to enhance diaphragmatic contractility and reduce muscle fatigue. Anticoagulation should be considered in patients at high risk for thromboembolic disease. In acutely decompensated COPD, early initiation of corticosteroids and antibiotics is indicated. Improvement of the underlying respiratory disorder typically results in improved right ventricular function.
Medications
Furosemide may be administered at doses of 20–60 mg intravenously in adults, with pediatric dosing starting at 1 mg/kg and titrated as needed to a maximum of 6 mg/kg. Terbutaline may be administered at a dose of 0.25 mg subcutaneously.
Disposition and Follow-Up
Hospital admission is indicated for patients with new-onset hypoxia, anasarca, severe respiratory failure, or when required by the severity of the underlying disease. Patients without hypoxia or with stable oxygen requirements may be considered for discharge. Close outpatient follow-up is essential once the underlying etiology has responded to acute management, and evaluation for sleep apnea with a sleep study should be coordinated by the patient’s physician when indicated. Home oxygen therapy should be ensured for patients with chronic hypoxia.
Key Clinical Insights and Common Management Errors
Physical examination findings may be unreliable in patients with COPD because chest hyperinflation often obscures classic signs of cor pulmonale. Vasodilator therapy should be reserved for cases in which conventional management and adequate oxygenation have failed and should be used with caution.
Definition and Pathophysiologic Overview
Cor pulmonale refers to right ventricular hypertrophy or dilation caused by elevated pulmonary artery pressure. Right ventricular hypertrophy resulting from primary left-sided heart disease or congenital cardiac abnormalities is not classified as cor pulmonale. The disorder may be acute or chronic, depending on the rapidity and duration of pulmonary hypertension and the adaptive capacity of the right ventricle.
Acute cor pulmonale is marked by sudden right ventricular dilation with thinning and stretching of the ventricular wall, caused by an abrupt increase in right ventricular afterload due to acute pulmonary hypertension. The most common cause is a massive pulmonary embolism. Chronic cor pulmonale develops from long-standing pulmonary hypertension and is characterized initially by right ventricular hypertrophy, followed by dilation and eventual right-sided heart failure. This chronic form most often results from persistent alveolar hypoxia and represents an adaptive response to sustained elevation in pulmonary vascular resistance.
The pulmonary circulation is normally a low-pressure, low-resistance system with thin-walled, distensible arteries. Mean pulmonary arterial pressure typically ranges from 12 to 15 mm Hg, while normal left atrial pressure is approximately 6 to 10 mm Hg, resulting in a small pressure gradient of 6 to 9 mm Hg to drive pulmonary blood flow. Pulmonary arterial pressure is determined by cardiac output, pulmonary venous pressure, and pulmonary vascular resistance. Pulmonary hypertension may arise from markedly increased cardiac output, left-to-right shunts due to congenital heart disease, or most commonly hypoxia. Hypoxic pulmonary vasoconstriction is an adaptive response to alveolar hypoxia that preserves ventilation–perfusion matching by increasing pulmonary arterial pressure to maintain flow through the pulmonary vascular bed. Pulmonary embolism produces a similar effect by increasing resistance to pulmonary blood flow, while increased blood viscosity or elevated intrathoracic pressure can further impair pulmonary circulation.
Pulmonary hypertension is categorized into five groups. Group 1 includes pulmonary arterial hypertension. Group 2 consists of pulmonary hypertension due to left-sided heart disease, in which associated right ventricular dysfunction is not considered cor pulmonale. Group 3 includes pulmonary hypertension due to lung disease and/or hypoxia. Group 4 encompasses chronic thromboembolic pulmonary hypertension. Group 5 includes pulmonary hypertension with unclear or multifactorial mechanisms.
Epidemiology
Approximately 86,000 deaths occur annually from chronic obstructive pulmonary disease, with associated right ventricular failure contributing significantly in many cases. Cor pulmonale accounts for 10–30% of heart failure admissions in the United States. Among patients older than 50 years with COPD, about half develop pulmonary hypertension and are therefore at risk for cor pulmonale. Disease progression is closely tied to the severity of the underlying pulmonary disorder, and once cor pulmonale develops, the estimated five-year survival rate is approximately 30%.
Etiology
Chronic hypoxia is the most frequent cause of cor pulmonale and may result from COPD, residence at high altitude, obstructive sleep apnea, or chest wall deformities such as kyphoscoliosis. Other causes include pulmonary embolism and interstitial lung diseases such as scleroderma, systemic lupus erythematosus, mixed connective tissue disease, sarcoidosis, pulmonary Langerhans cell histiocytosis, neurofibromatosis, lymphangioleiomyomatosis, and cystic fibrosis. Additional contributing factors include severe anemia, obesity, pulmonary veno-occlusive disease, pulmonary vascular obstruction from tumors or lymphadenopathy, increased blood viscosity as seen in polycythemia vera or leukemia, and elevated intrathoracic pressure due to mechanical ventilation with positive end-expiratory pressure. Idiopathic primary pulmonary hypertension is a less common cause.
Clinical Manifestations
Patients frequently present with exertional dyspnea, easy fatigability, weakness, and reduced exercise tolerance. Additional symptoms include exertional syncope, cough, hemoptysis, and exertional angina even in the absence of coronary artery disease. Anorexia, right upper quadrant discomfort, wheezing, hoarseness, and weight gain may occur as right-sided heart failure progresses. Signs of volume overload include hepatomegaly, ascites, and peripheral edema. In advanced disease, cardiogenic shock may develop, manifested by oliguria, cool extremities, and pulmonary edema resulting from interventricular septal displacement that impairs left ventricular diastolic filling.
History commonly reveals exercise intolerance, palpitations, chest pain, lightheadedness, syncope, and lower extremity swelling. Physical examination may show jugular venous distention with prominent A and V waves, increased chest diameter, crackles or wheezes on lung auscultation, and a left parasternal heave. Splitting of the second heart sound or murmurs related to pulmonary vasculature abnormalities may be present. A hepatojugular reflex, pulsatile liver, and pitting edema of the lower extremities are typical findings in advanced cases.
Diagnostic Evaluation
Pulse oximetry or arterial blood gas analysis typically demonstrates resting hypoxemia with arterial oxygen tensions of 40–60 mm Hg and resting carbon dioxide levels often between 40 and 70 mm Hg. Hematocrit is frequently elevated due to secondary polycythemia. Elevated B-type natriuretic peptide levels are sensitive for moderate to severe pulmonary hypertension and may independently predict mortality, although elevation alone is insufficient to establish the diagnosis of cor pulmonale. Other laboratory tests are generally of limited diagnostic value.
Chest radiography often reveals signs of pulmonary hypertension, including enlarged pulmonary arteries greater than 16–18 mm and an enlarged right ventricular silhouette. Although abnormalities are seen in more than 90% of patients, chest radiographs do not reliably indicate disease severity. Pleural effusions are not a feature of isolated cor pulmonale. Electrocardiography may demonstrate right-axis deviation, right bundle branch block, right ventricular hypertrophy with dominant R waves in leads V1 and V2, prominent S waves in leads V5 and V6, small R waves with deep S waves across the precordium, and right atrial enlargement with tall, peaked P waves consistent with P pulmonale. Acute cor pulmonale may show an S1Q3 pattern, transient hypoxia-related changes, and right precordial T-wave flattening.
Echocardiography is the preferred noninvasive diagnostic modality and may demonstrate right ventricular hypertrophy or dilation, tricuspid regurgitation, and Doppler-based estimation of pulmonary artery pressure and right ventricular ejection fraction. Chest computed tomography, ventilation–perfusion scanning, or pulmonary angiography are useful when acute cor pulmonale is suspected, particularly in cases of pulmonary embolism. Magnetic resonance imaging offers superior assessment of right ventricular size and function compared with echocardiography. Pulmonary function testing may reveal reduced diffusion capacity associated with pulmonary hypertension. Right-heart catheterization remains the most accurate method for assessing pulmonary vascular hemodynamics and provides precise measurements of pulmonary arterial and pulmonary capillary wedge pressures.
Differential Diagnosis
The differential diagnosis includes primary left-sided heart disease such as mitral stenosis, congenital heart disease including Eisenmenger syndrome with left-to-right shunting, hypothyroidism, and cirrhosis.
Management and Prehospital Care
Prehospital treatment is supportive and includes supplemental oxygen titrated to achieve arterial oxygen saturation of approximately 90%, establishment of intravenous access, continuous cardiac monitoring, and pulse oximetry. Bronchospasm related to underlying respiratory disease should be treated with beta-agonist nebulizers. Vasodilators and diuretics have no role in the prehospital setting. Patients with severe hypoxia may require endotracheal intubation.
Emergency Department Treatment
Management in the emergency department is directed at treating the underlying disease process and reducing pulmonary hypertension. Supplemental oxygen should be administered to raise arterial oxygen saturation to 90%, thereby reducing pulmonary vasoconstriction and right ventricular afterload while improving cardiac output and promoting diuresis. Careful monitoring of ventilation and carbon dioxide levels is essential, as hypercapnia may suppress respiratory drive and worsen acidosis. Diuretics such as furosemide may be used cautiously to reduce circulating blood volume and pulmonary artery pressure, with close attention to avoiding hypovolemia and electrolyte disturbances. Patients should be maintained on salt and fluid restriction. Digoxin has no role in the treatment of cor pulmonale.
Bronchodilator therapy is particularly beneficial in patients with COPD, as it reduces ventricular afterload and improves airflow. Selective beta-adrenergic agents such as subcutaneous terbutaline may be administered, and theophylline may be considered to enhance diaphragmatic contractility and reduce muscle fatigue. Anticoagulation should be considered in patients at high risk for thromboembolic disease. In acutely decompensated COPD, early initiation of corticosteroids and antibiotics is indicated. Improvement of the underlying respiratory disorder typically results in improved right ventricular function.
Medications
Furosemide may be administered at doses of 20–60 mg intravenously in adults, with pediatric dosing starting at 1 mg/kg and titrated as needed to a maximum of 6 mg/kg. Terbutaline may be administered at a dose of 0.25 mg subcutaneously.
Disposition and Follow-Up
Hospital admission is indicated for patients with new-onset hypoxia, anasarca, severe respiratory failure, or when required by the severity of the underlying disease. Patients without hypoxia or with stable oxygen requirements may be considered for discharge. Close outpatient follow-up is essential once the underlying etiology has responded to acute management, and evaluation for sleep apnea with a sleep study should be coordinated by the patient’s physician when indicated. Home oxygen therapy should be ensured for patients with chronic hypoxia.
Key Clinical Insights and Common Management Errors
Physical examination findings may be unreliable in patients with COPD because chest hyperinflation often obscures classic signs of cor pulmonale. Vasodilator therapy should be reserved for cases in which conventional management and adequate oxygenation have failed and should be used with caution.
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Emergency And Acute Medicine – Cyanosis
Overview
Cyanosis is an abnormal bluish discoloration of the skin or mucous membranes caused by increased concentrations of deoxygenated hemoglobin or abnormal hemoglobin derivatives within capillary blood. Clinically significant levels include deoxygenated hemoglobin greater than 5 g/dL, methemoglobin greater than 1.5 g/dL, or sulfhemoglobin greater than 0.5 g/dL. The absolute amount of deoxygenated hemoglobin determines the blue coloration, not the oxyhemoglobin concentration. Cyanosis is more apparent in patients with polycythemia and may be difficult to detect in anemic patients. Skin thickness and pigmentation influence visibility. Cyanosis may be central, reflecting systemic hypoxemia or abnormal hemoglobin, or peripheral, reflecting increased oxygen extraction or impaired blood flow.
Pathophysiologic Types
Central cyanosis results from hypoxemia, right-to-left cardiac shunting, or abnormal hemoglobin species. Peripheral cyanosis occurs when tissues extract excessive oxygen due to hypoperfusion, vasoconstriction from cold exposure, or arterial or venous insufficiency. Acrocyanosis is a painless, symmetric bluish discoloration of distal extremities with an unclear underlying mechanism.
Causes
Central causes include impaired pulmonary function from hypoventilation, ventilation–perfusion mismatch, or diffusion defects; intracardiac or intrapulmonary shunts; high-altitude exposure; and abnormal hemoglobins. Peripheral causes include shock, cold exposure, arterial insufficiency, venous insufficiency, Raynaud phenomenon, and acrocyanosis. Abnormal hemoglobin states include congenital or acquired methemoglobinemia and sulfhemoglobinemia, often related to medications, chemicals, or genetic enzyme deficiencies.
Pediatric Considerations
In children, cyanosis may reflect cyanotic congenital heart disease such as tetralogy of Fallot, transposition of the great vessels, truncus arteriosus, pulmonary or tricuspid atresia, Ebstein anomaly, total anomalous pulmonary venous return, or duct-dependent lesions. Respiratory causes include upper and lower airway obstruction, bronchiolitis, pneumonia, pulmonary edema, or foreign body aspiration. Neurologic causes such as breath-holding spells should also be considered.
Clinical Presentation
Patients exhibit a bluish discoloration of skin or mucous membranes that typically blanches with pressure. Methemoglobinemia may produce chocolate-brown blood or slate-gray discoloration. History should establish onset, progression, associated symptoms such as dyspnea or altered mental status, medication use, and possible occupational or chemical exposures. Physical examination focuses on respiratory distress, hemodynamic stability, distribution of discoloration, cardiac and pulmonary findings, presence of clubbing, and peripheral perfusion.
Initial Assessment
Airway and ventilation assessment is the first priority. Hypoxemia from cardiac or pulmonary causes is most common and should be addressed immediately. Abnormal hemoglobin states should be considered when cyanosis persists despite adequate oxygenation.
Diagnostic Evaluation
Pulse oximetry may be misleading in abnormal hemoglobin states, hypoperfusion, or pigmented skin. Arterial blood gas analysis assesses oxygen tension and saturation; cyanosis with a normal PaO₂ suggests methemoglobinemia. Chocolate-colored blood supports this diagnosis, which should be confirmed by measuring methemoglobin levels. Laboratory studies include complete blood count and basic chemistries. Imaging such as chest radiography and targeted neck films helps evaluate pulmonary, cardiac, or airway pathology. Echocardiography is useful when shunt or structural heart disease is suspected.
Conditions To Differentiate
Noncyanotic causes of skin discoloration that do not blanch include drug-induced pigmentation, heavy metal deposition, metabolic disorders, tattoos, and rare conditions such as chromhidrosis.
Emergency Management
Prehospital and emergency care focuses on securing the airway, providing 100% oxygen via a nonrebreather mask, correcting ventilation problems, and supporting circulation. Bronchodilators, racemic epinephrine, diuretics, or prostaglandin E1 may be required depending on the underlying cause. Methylene blue is indicated for symptomatic methemoglobinemia with levels above 30%, except in patients with glucose-6-phosphate dehydrogenase deficiency.
Disposition
Most patients with cyanosis require hospital admission, and any instability mandates intensive care. Discharge may be considered only when a reversible cause has been identified, treated, and resolved, with stable oxygenation and close follow-up arranged.
Practical Insights And Common Diagnostic Errors
Always presume hypoxemia first and rapidly evaluate airway and breathing. Cyanosis that does not improve with high-flow oxygen or is associated with chocolate-colored blood should prompt evaluation for methemoglobinemia. Failure to recognize abnormal hemoglobin states is a frequent cause of delayed diagnosis.
Overview
Cyanosis is an abnormal bluish discoloration of the skin or mucous membranes caused by increased concentrations of deoxygenated hemoglobin or abnormal hemoglobin derivatives within capillary blood. Clinically significant levels include deoxygenated hemoglobin greater than 5 g/dL, methemoglobin greater than 1.5 g/dL, or sulfhemoglobin greater than 0.5 g/dL. The absolute amount of deoxygenated hemoglobin determines the blue coloration, not the oxyhemoglobin concentration. Cyanosis is more apparent in patients with polycythemia and may be difficult to detect in anemic patients. Skin thickness and pigmentation influence visibility. Cyanosis may be central, reflecting systemic hypoxemia or abnormal hemoglobin, or peripheral, reflecting increased oxygen extraction or impaired blood flow.
Pathophysiologic Types
Central cyanosis results from hypoxemia, right-to-left cardiac shunting, or abnormal hemoglobin species. Peripheral cyanosis occurs when tissues extract excessive oxygen due to hypoperfusion, vasoconstriction from cold exposure, or arterial or venous insufficiency. Acrocyanosis is a painless, symmetric bluish discoloration of distal extremities with an unclear underlying mechanism.
Causes
Central causes include impaired pulmonary function from hypoventilation, ventilation–perfusion mismatch, or diffusion defects; intracardiac or intrapulmonary shunts; high-altitude exposure; and abnormal hemoglobins. Peripheral causes include shock, cold exposure, arterial insufficiency, venous insufficiency, Raynaud phenomenon, and acrocyanosis. Abnormal hemoglobin states include congenital or acquired methemoglobinemia and sulfhemoglobinemia, often related to medications, chemicals, or genetic enzyme deficiencies.
Pediatric Considerations
In children, cyanosis may reflect cyanotic congenital heart disease such as tetralogy of Fallot, transposition of the great vessels, truncus arteriosus, pulmonary or tricuspid atresia, Ebstein anomaly, total anomalous pulmonary venous return, or duct-dependent lesions. Respiratory causes include upper and lower airway obstruction, bronchiolitis, pneumonia, pulmonary edema, or foreign body aspiration. Neurologic causes such as breath-holding spells should also be considered.
Clinical Presentation
Patients exhibit a bluish discoloration of skin or mucous membranes that typically blanches with pressure. Methemoglobinemia may produce chocolate-brown blood or slate-gray discoloration. History should establish onset, progression, associated symptoms such as dyspnea or altered mental status, medication use, and possible occupational or chemical exposures. Physical examination focuses on respiratory distress, hemodynamic stability, distribution of discoloration, cardiac and pulmonary findings, presence of clubbing, and peripheral perfusion.
Initial Assessment
Airway and ventilation assessment is the first priority. Hypoxemia from cardiac or pulmonary causes is most common and should be addressed immediately. Abnormal hemoglobin states should be considered when cyanosis persists despite adequate oxygenation.
Diagnostic Evaluation
Pulse oximetry may be misleading in abnormal hemoglobin states, hypoperfusion, or pigmented skin. Arterial blood gas analysis assesses oxygen tension and saturation; cyanosis with a normal PaO₂ suggests methemoglobinemia. Chocolate-colored blood supports this diagnosis, which should be confirmed by measuring methemoglobin levels. Laboratory studies include complete blood count and basic chemistries. Imaging such as chest radiography and targeted neck films helps evaluate pulmonary, cardiac, or airway pathology. Echocardiography is useful when shunt or structural heart disease is suspected.
Conditions To Differentiate
Noncyanotic causes of skin discoloration that do not blanch include drug-induced pigmentation, heavy metal deposition, metabolic disorders, tattoos, and rare conditions such as chromhidrosis.
Emergency Management
Prehospital and emergency care focuses on securing the airway, providing 100% oxygen via a nonrebreather mask, correcting ventilation problems, and supporting circulation. Bronchodilators, racemic epinephrine, diuretics, or prostaglandin E1 may be required depending on the underlying cause. Methylene blue is indicated for symptomatic methemoglobinemia with levels above 30%, except in patients with glucose-6-phosphate dehydrogenase deficiency.
Disposition
Most patients with cyanosis require hospital admission, and any instability mandates intensive care. Discharge may be considered only when a reversible cause has been identified, treated, and resolved, with stable oxygenation and close follow-up arranged.
Practical Insights And Common Diagnostic Errors
Always presume hypoxemia first and rapidly evaluate airway and breathing. Cyanosis that does not improve with high-flow oxygen or is associated with chocolate-colored blood should prompt evaluation for methemoglobinemia. Failure to recognize abnormal hemoglobin states is a frequent cause of delayed diagnosis.
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Emergency And Acute Medicine – Cyanide Poisoning
Overview
Cyanide toxicity occurs through inhalation or gastrointestinal absorption. Cyanide is an intracellular toxin that disrupts aerobic metabolism by inhibiting oxidative phosphorylation, resulting in impaired oxygen utilization and reduced ATP production. Detoxification primarily occurs via the hepatic mitochondrial enzyme rhodanese, which combines cyanide with sulfur in an irreversible reaction to form the less toxic, water-soluble thiocyanate. Cyanide can also bind hemoglobin to form reversible cyanhemoglobin or bind hydroxocobalamin to form nontoxic cyanocobalamin. Effective detoxification depends on adequate sulfur availability, particularly thiosulfate.
Causes And Sources
Cyanide exposure most commonly occurs during fires as a combustion by-product of natural and synthetic materials. Industrial sources include metal plating, microchip and plastic manufacturing, chemical synthesis, pesticides, and solvents such as artificial nail remover and metal polishes. Cyanide may also be produced during nitroprusside metabolism and by certain bacterial infections. Dietary sources include amygdalin-containing plants such as apricot pits, peach pits, apple seeds, pear seeds, and cassava. Jewelry making is another recognized exposure risk.
Clinical Features
The heart and brain are the most sensitive organs and are typically affected first. Neurologic manifestations include headache, confusion, syncope, seizures, and coma. Cardiovascular findings include dyspnea, chest pain, rapid progression to cardiorespiratory collapse, and death. Gastrointestinal symptoms such as nausea and vomiting may occur. Oral exposure can be caustic, with as little as 50 mg causing death. Inhalational exposure to 50 ppm may cause anxiety, palpitations, dyspnea, and headache, while concentrations of 100–135 ppm can be lethal in less than one hour.
Initial Evaluation
A history suggestive of smoke inhalation, industrial exposure, or intentional ingestion should raise suspicion. Classic findings such as the odor of bitter almonds or bright red retinal vessels are often absent. Key clinical clues include abrupt onset or rapid deterioration, severe lactic acidosis, and elevated venous oxygen saturation due to impaired cellular oxygen utilization, resulting in arterialized venous blood gases.
Diagnostic Studies
Laboratory evaluation typically includes complete blood count, metabolic panel, liver profile, creatine phosphokinase, carboxyhemoglobin, and methemoglobin levels. Cyanide levels are usually send-out tests and not available in real time; levels above 0.5–1 mg/L are toxic, and levels of 2.5–3 mg/L are often fatal. Blood gas analysis may show elevated mixed venous oxygen saturation, reduced arteriovenous oxygen difference, and markedly elevated lactate levels greater than 8 mmol/L, which serve as a useful surrogate marker when exposure history is consistent. Chest radiography may assist in evaluating concurrent inhalation injury.
Conditions To Differentiate
The differential diagnosis includes carbon monoxide poisoning, hydrogen sulfide exposure, methemoglobinemia, sulfhemoglobinemia, inert gas asphyxiation, and other causes of high anion gap metabolic acidosis.
Prehospital Management
Immediate removal from the source of exposure is critical, while preventing secondary contamination of rescuers. Contaminated clothing should be removed and bagged, and liquid exposures require thorough washing with soap and water. Vapor exposures may resolve with simple removal from the environment.
Emergency Stabilization
Initial management follows standard airway, breathing, and circulation principles. Administer 100% oxygen regardless of measured oxygen tension, as it acts synergistically with antidotes. Gastric lavage and activated charcoal may be considered for recent oral ingestion if no contraindications exist. Dermal exposures require standard decontamination measures.
Definitive Treatment
Hydroxocobalamin is the preferred first-line antidote for patients with significant toxicity, including persistent high anion gap metabolic acidosis, hyperlactatemia, seizures, syncope, dysrhythmias, or hypotension. It binds cyanide to form cyanocobalamin, which is renally excreted. Advantages include the absence of methemoglobinemia and hypotension. Limitations include cost, drug incompatibilities within IV lines, and interference with certain laboratory assays.
An alternative is the traditional cyanide antidote kit, which includes amyl nitrite, sodium nitrite, and sodium thiosulfate. Nitrites induce methemoglobinemia to sequester cyanide away from mitochondria, while sodium thiosulfate enhances enzymatic detoxification via rhodanese. Nitrites should not be used empirically and require caution due to the risk of excessive methemoglobinemia and hypotension. Hyperbaric oxygen therapy may be considered as adjunctive treatment to maximize tissue oxygenation.
Medication Summary
First-line therapy is hydroxocobalamin administered intravenously at weight-based dosing, with repeat dosing if necessary. Activated charcoal may be used for recent ingestions. Second-line therapy involves the cyanide antidote kit, including carefully dosed nitrites and sodium thiosulfate. Special dosing considerations apply in pediatric patients, pregnancy, and those with hepatic or renal impairment.
Disposition And Follow-Up
All symptomatic patients require intensive care unit admission. Asymptomatic patients may be discharged after at least four hours of observation if no symptoms develop, as survival beyond this period is usually associated with full recovery. Psychiatric evaluation is indicated for intentional exposures.
Key Clinical Insights And Common Errors
In patients presenting with hypotension, seizures, altered mental status, severe lactic acidosis, and high anion gap metabolic acidosis, cyanide poisoning should be strongly considered and treated empirically. Serum lactate is a valuable surrogate marker when exposure history is suggestive. Victims of smoke inhalation may have combined cyanide toxicity, carbon monoxide poisoning, and methemoglobinemia. When carbon monoxide levels are markedly elevated, concomitant cyanide exposure should be suspected. To avoid worsening oxygen delivery, initial treatment should prioritize hydroxocobalamin or sodium thiosulfate without nitrites when methemoglobinemia would be harmful.
Overview
Cyanide toxicity occurs through inhalation or gastrointestinal absorption. Cyanide is an intracellular toxin that disrupts aerobic metabolism by inhibiting oxidative phosphorylation, resulting in impaired oxygen utilization and reduced ATP production. Detoxification primarily occurs via the hepatic mitochondrial enzyme rhodanese, which combines cyanide with sulfur in an irreversible reaction to form the less toxic, water-soluble thiocyanate. Cyanide can also bind hemoglobin to form reversible cyanhemoglobin or bind hydroxocobalamin to form nontoxic cyanocobalamin. Effective detoxification depends on adequate sulfur availability, particularly thiosulfate.
Causes And Sources
Cyanide exposure most commonly occurs during fires as a combustion by-product of natural and synthetic materials. Industrial sources include metal plating, microchip and plastic manufacturing, chemical synthesis, pesticides, and solvents such as artificial nail remover and metal polishes. Cyanide may also be produced during nitroprusside metabolism and by certain bacterial infections. Dietary sources include amygdalin-containing plants such as apricot pits, peach pits, apple seeds, pear seeds, and cassava. Jewelry making is another recognized exposure risk.
Clinical Features
The heart and brain are the most sensitive organs and are typically affected first. Neurologic manifestations include headache, confusion, syncope, seizures, and coma. Cardiovascular findings include dyspnea, chest pain, rapid progression to cardiorespiratory collapse, and death. Gastrointestinal symptoms such as nausea and vomiting may occur. Oral exposure can be caustic, with as little as 50 mg causing death. Inhalational exposure to 50 ppm may cause anxiety, palpitations, dyspnea, and headache, while concentrations of 100–135 ppm can be lethal in less than one hour.
Initial Evaluation
A history suggestive of smoke inhalation, industrial exposure, or intentional ingestion should raise suspicion. Classic findings such as the odor of bitter almonds or bright red retinal vessels are often absent. Key clinical clues include abrupt onset or rapid deterioration, severe lactic acidosis, and elevated venous oxygen saturation due to impaired cellular oxygen utilization, resulting in arterialized venous blood gases.
Diagnostic Studies
Laboratory evaluation typically includes complete blood count, metabolic panel, liver profile, creatine phosphokinase, carboxyhemoglobin, and methemoglobin levels. Cyanide levels are usually send-out tests and not available in real time; levels above 0.5–1 mg/L are toxic, and levels of 2.5–3 mg/L are often fatal. Blood gas analysis may show elevated mixed venous oxygen saturation, reduced arteriovenous oxygen difference, and markedly elevated lactate levels greater than 8 mmol/L, which serve as a useful surrogate marker when exposure history is consistent. Chest radiography may assist in evaluating concurrent inhalation injury.
Conditions To Differentiate
The differential diagnosis includes carbon monoxide poisoning, hydrogen sulfide exposure, methemoglobinemia, sulfhemoglobinemia, inert gas asphyxiation, and other causes of high anion gap metabolic acidosis.
Prehospital Management
Immediate removal from the source of exposure is critical, while preventing secondary contamination of rescuers. Contaminated clothing should be removed and bagged, and liquid exposures require thorough washing with soap and water. Vapor exposures may resolve with simple removal from the environment.
Emergency Stabilization
Initial management follows standard airway, breathing, and circulation principles. Administer 100% oxygen regardless of measured oxygen tension, as it acts synergistically with antidotes. Gastric lavage and activated charcoal may be considered for recent oral ingestion if no contraindications exist. Dermal exposures require standard decontamination measures.
Definitive Treatment
Hydroxocobalamin is the preferred first-line antidote for patients with significant toxicity, including persistent high anion gap metabolic acidosis, hyperlactatemia, seizures, syncope, dysrhythmias, or hypotension. It binds cyanide to form cyanocobalamin, which is renally excreted. Advantages include the absence of methemoglobinemia and hypotension. Limitations include cost, drug incompatibilities within IV lines, and interference with certain laboratory assays.
An alternative is the traditional cyanide antidote kit, which includes amyl nitrite, sodium nitrite, and sodium thiosulfate. Nitrites induce methemoglobinemia to sequester cyanide away from mitochondria, while sodium thiosulfate enhances enzymatic detoxification via rhodanese. Nitrites should not be used empirically and require caution due to the risk of excessive methemoglobinemia and hypotension. Hyperbaric oxygen therapy may be considered as adjunctive treatment to maximize tissue oxygenation.
Medication Summary
First-line therapy is hydroxocobalamin administered intravenously at weight-based dosing, with repeat dosing if necessary. Activated charcoal may be used for recent ingestions. Second-line therapy involves the cyanide antidote kit, including carefully dosed nitrites and sodium thiosulfate. Special dosing considerations apply in pediatric patients, pregnancy, and those with hepatic or renal impairment.
Disposition And Follow-Up
All symptomatic patients require intensive care unit admission. Asymptomatic patients may be discharged after at least four hours of observation if no symptoms develop, as survival beyond this period is usually associated with full recovery. Psychiatric evaluation is indicated for intentional exposures.
Key Clinical Insights And Common Errors
In patients presenting with hypotension, seizures, altered mental status, severe lactic acidosis, and high anion gap metabolic acidosis, cyanide poisoning should be strongly considered and treated empirically. Serum lactate is a valuable surrogate marker when exposure history is suggestive. Victims of smoke inhalation may have combined cyanide toxicity, carbon monoxide poisoning, and methemoglobinemia. When carbon monoxide levels are markedly elevated, concomitant cyanide exposure should be suspected. To avoid worsening oxygen delivery, initial treatment should prioritize hydroxocobalamin or sodium thiosulfate without nitrites when methemoglobinemia would be harmful.
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Emergency and Acute Medicine – Corneal Abrasion
Definition and General Description
A corneal abrasion is defined as any tear, defect, or disruption of the corneal epithelium. It is a common ocular injury that may result from direct trauma, spontaneous epithelial breakdown, foreign body exposure, or contact lens use. Because the cornea is densely innervated, even small epithelial defects can cause significant pain and visual disturbance.
Etiology and Mechanisms of Injury
Traumatic corneal abrasions are most frequently caused by fingernails, tree branches, hairbrushes or combs, sand or small stones, snow, pens or pencils, toys, chemical exposures, airbag deployment, pepper spray, paper or cardboard, makeup applicators, and animal paws. Foreign body–related abrasions may occur from materials such as wood, glass, metal, rust, plastic, fiberglass, or vegetable matter, including foreign bodies trapped beneath the eyelid. Contact lens–related abrasions are associated with overwear, improper lens fit, or inadequate lens hygiene. Spontaneous corneal abrasions usually occur in patients with a history of prior corneal trauma or those with an underlying defect of the corneal epithelium, such as recurrent corneal erosion syndrome.
Clinical Presentation
Patients typically present with severe ocular pain accompanied by a gritty or scratchy sensation, excessive tearing, blepharospasm, and a persistent foreign body sensation. Photophobia is common and may be pronounced if traumatic iritis is present. Additional symptoms include conjunctival injection, blurred or diminished vision, and headache.
The history should specifically address any direct trauma to the eye, known or suspected foreign body exposure, contact lens use, previous corneal abrasions, prior ocular or periocular surgery, pre-existing visual impairment, and the timing of symptom onset. Associated injuries or symptoms should be assessed, as well as any treatment attempted before presentation. Inquiry about occupational or recreational eye protection, systemic diseases such as diabetes or autoimmune disorders, and tetanus immunization status is also important.
Pediatric Considerations
In children, the presentation may differ significantly from adults. Excessive crying may be the primary manifestation. In infants younger than 12 months, there is often no clear history of eye trauma, and corneal abrasion may present as an inconsolable crying infant. In neonates and infants aged 1–12 weeks, corneal abrasions may be incidental findings and not the cause of irritability. Children older than 12 months are more likely to have a history of minor eye trauma and demonstrate more obvious ocular signs.
Physical Examination and Diagnostic Evaluation
If clinically indicated, the initial evaluation should include assessment for other life-threatening injuries following standard primary survey principles. A focused but complete eye examination is essential and should aim to exclude penetrating injury or infection. This includes gross inspection of the eye, assessment of visual acuity, and a penlight examination to evaluate conjunctival injection, pupil shape and reactivity, and the presence of corneal opacity or infiltrate. The upper eyelids should be everted to assess for retained foreign bodies. Slit-lamp examination allows evaluation of the anterior chamber for inflammation, detection of corneal laceration or penetrating trauma, and identification of infiltrates. Fluorescein staining is used to confirm the diagnosis and determine the size and location of the epithelial defect.
In pediatric patients, handheld slit lamps and Wood lamps can be particularly helpful in facilitating examination.
Differential Diagnosis
The differential diagnosis includes viral or bacterial conjunctivitis, corneal ulcer, acute glaucoma, herpes zoster ophthalmicus, infectious or ultraviolet keratitis, recurrent corneal erosion syndrome, and uveitis. More serious ocular injuries must also be considered, including corneal laceration or perforation, hyphema, iris prolapse, and lens disruption.
Initial Management and Emergency Department Care
Initial therapy includes instillation of a topical anesthetic, such as proparacaine or tetracaine, to facilitate examination. In the emergency department, superficial foreign bodies should be removed when present. A residual rust ring does not require emergent removal and can be addressed within 24–48 hours. Pain control may be achieved with oral NSAIDs, acetaminophen, or oral opioids when necessary.
Topical NSAIDs such as diclofenac or ketorolac have demonstrated effectiveness for pain control, although there are rare reports of adverse effects; these agents should be avoided in patients with pre-existing ocular surface disease or those who have recently undergone eye surgery. Cycloplegic agents may be used selectively to relieve ciliary spasm, including cyclopentolate, tropicamide, or homatropine.
Topical antibiotics are commonly prescribed despite limited evidence, primarily to prevent secondary infection. Ointments are preferred over drops due to their lubricating properties. Antibiotics should be discontinued once the patient has been symptom free for 24 hours. Contact lens wearers require antipseudomonal coverage, such as ciprofloxacin. Eye patching does not improve healing or pain control, particularly within the first 24 hours, and is not recommended for small abrasions. Patching should never be used in contact lens wearers or in injuries with high infection risk, such as those involving organic matter. The role of patching in large abrasions greater than 10 mm remains unclear.
Contact lenses should not be worn until the abrasion has fully healed and the eye has felt normal for at least one week without medication. In cases of severe pain, a bandage contact lens may be considered, provided there is no evidence of infection and close daily follow-up is ensured. Routine tetanus prophylaxis is not required, but immunization should be updated if the abrasion is caused by or contaminated with dirt or organic material. Emergent ophthalmology consultation is required for suspected intraocular foreign bodies, penetrating globe injuries, or the presence of corneal infiltrates, white spots, or opacities.
Medications
Commonly used medications include topical ciprofloxacin 0.35% drops four times daily, erythromycin 0.5% ointment four times daily, gentamicin drops or ointment, sulfacetamide drops or ointment, and tobramycin drops or ointment. Cycloplegics such as cyclopentolate, tropicamide, or homatropine may be used as indicated. Topical NSAIDs include diclofenac 0.1% or ketorolac 0.5% drops four times daily. Proparacaine should be used only once in the emergency department and not prescribed for outpatient use.
Disposition and Follow-Up
Hospital admission is reserved for patients with associated injuries requiring inpatient care. All uncomplicated corneal abrasions may be discharged from the emergency department. Although no definitive studies define optimal follow-up, standard practice recommends follow-up for all corneal abrasions to ensure complete healing without infection or scarring. Contact lens wearers, patients with patched eyes, or those with bandage contact lenses should be re-evaluated by ophthalmology within 24 hours. Central or large abrasions also warrant ophthalmologic follow-up within 24 hours, while smaller peripheral abrasions may be rechecked within 48–72 hours.
Essential Clinical Cautions and Common Errors
Clinicians must always carefully evaluate for penetrating globe injuries and signs of infection. Patients should never be discharged with topical anesthetics, as these agents are toxic to the corneal epithelium and delay healing, despite limited evidence suggesting dilute formulations may be safe. Mydriatic agents should not be used in patients with a history of glaucoma. Contact lens use should not be resumed until the patient has been evaluated and cleared by ophthalmology.
Definition and General Description
A corneal abrasion is defined as any tear, defect, or disruption of the corneal epithelium. It is a common ocular injury that may result from direct trauma, spontaneous epithelial breakdown, foreign body exposure, or contact lens use. Because the cornea is densely innervated, even small epithelial defects can cause significant pain and visual disturbance.
Etiology and Mechanisms of Injury
Traumatic corneal abrasions are most frequently caused by fingernails, tree branches, hairbrushes or combs, sand or small stones, snow, pens or pencils, toys, chemical exposures, airbag deployment, pepper spray, paper or cardboard, makeup applicators, and animal paws. Foreign body–related abrasions may occur from materials such as wood, glass, metal, rust, plastic, fiberglass, or vegetable matter, including foreign bodies trapped beneath the eyelid. Contact lens–related abrasions are associated with overwear, improper lens fit, or inadequate lens hygiene. Spontaneous corneal abrasions usually occur in patients with a history of prior corneal trauma or those with an underlying defect of the corneal epithelium, such as recurrent corneal erosion syndrome.
Clinical Presentation
Patients typically present with severe ocular pain accompanied by a gritty or scratchy sensation, excessive tearing, blepharospasm, and a persistent foreign body sensation. Photophobia is common and may be pronounced if traumatic iritis is present. Additional symptoms include conjunctival injection, blurred or diminished vision, and headache.
The history should specifically address any direct trauma to the eye, known or suspected foreign body exposure, contact lens use, previous corneal abrasions, prior ocular or periocular surgery, pre-existing visual impairment, and the timing of symptom onset. Associated injuries or symptoms should be assessed, as well as any treatment attempted before presentation. Inquiry about occupational or recreational eye protection, systemic diseases such as diabetes or autoimmune disorders, and tetanus immunization status is also important.
Pediatric Considerations
In children, the presentation may differ significantly from adults. Excessive crying may be the primary manifestation. In infants younger than 12 months, there is often no clear history of eye trauma, and corneal abrasion may present as an inconsolable crying infant. In neonates and infants aged 1–12 weeks, corneal abrasions may be incidental findings and not the cause of irritability. Children older than 12 months are more likely to have a history of minor eye trauma and demonstrate more obvious ocular signs.
Physical Examination and Diagnostic Evaluation
If clinically indicated, the initial evaluation should include assessment for other life-threatening injuries following standard primary survey principles. A focused but complete eye examination is essential and should aim to exclude penetrating injury or infection. This includes gross inspection of the eye, assessment of visual acuity, and a penlight examination to evaluate conjunctival injection, pupil shape and reactivity, and the presence of corneal opacity or infiltrate. The upper eyelids should be everted to assess for retained foreign bodies. Slit-lamp examination allows evaluation of the anterior chamber for inflammation, detection of corneal laceration or penetrating trauma, and identification of infiltrates. Fluorescein staining is used to confirm the diagnosis and determine the size and location of the epithelial defect.
In pediatric patients, handheld slit lamps and Wood lamps can be particularly helpful in facilitating examination.
Differential Diagnosis
The differential diagnosis includes viral or bacterial conjunctivitis, corneal ulcer, acute glaucoma, herpes zoster ophthalmicus, infectious or ultraviolet keratitis, recurrent corneal erosion syndrome, and uveitis. More serious ocular injuries must also be considered, including corneal laceration or perforation, hyphema, iris prolapse, and lens disruption.
Initial Management and Emergency Department Care
Initial therapy includes instillation of a topical anesthetic, such as proparacaine or tetracaine, to facilitate examination. In the emergency department, superficial foreign bodies should be removed when present. A residual rust ring does not require emergent removal and can be addressed within 24–48 hours. Pain control may be achieved with oral NSAIDs, acetaminophen, or oral opioids when necessary.
Topical NSAIDs such as diclofenac or ketorolac have demonstrated effectiveness for pain control, although there are rare reports of adverse effects; these agents should be avoided in patients with pre-existing ocular surface disease or those who have recently undergone eye surgery. Cycloplegic agents may be used selectively to relieve ciliary spasm, including cyclopentolate, tropicamide, or homatropine.
Topical antibiotics are commonly prescribed despite limited evidence, primarily to prevent secondary infection. Ointments are preferred over drops due to their lubricating properties. Antibiotics should be discontinued once the patient has been symptom free for 24 hours. Contact lens wearers require antipseudomonal coverage, such as ciprofloxacin. Eye patching does not improve healing or pain control, particularly within the first 24 hours, and is not recommended for small abrasions. Patching should never be used in contact lens wearers or in injuries with high infection risk, such as those involving organic matter. The role of patching in large abrasions greater than 10 mm remains unclear.
Contact lenses should not be worn until the abrasion has fully healed and the eye has felt normal for at least one week without medication. In cases of severe pain, a bandage contact lens may be considered, provided there is no evidence of infection and close daily follow-up is ensured. Routine tetanus prophylaxis is not required, but immunization should be updated if the abrasion is caused by or contaminated with dirt or organic material. Emergent ophthalmology consultation is required for suspected intraocular foreign bodies, penetrating globe injuries, or the presence of corneal infiltrates, white spots, or opacities.
Medications
Commonly used medications include topical ciprofloxacin 0.35% drops four times daily, erythromycin 0.5% ointment four times daily, gentamicin drops or ointment, sulfacetamide drops or ointment, and tobramycin drops or ointment. Cycloplegics such as cyclopentolate, tropicamide, or homatropine may be used as indicated. Topical NSAIDs include diclofenac 0.1% or ketorolac 0.5% drops four times daily. Proparacaine should be used only once in the emergency department and not prescribed for outpatient use.
Disposition and Follow-Up
Hospital admission is reserved for patients with associated injuries requiring inpatient care. All uncomplicated corneal abrasions may be discharged from the emergency department. Although no definitive studies define optimal follow-up, standard practice recommends follow-up for all corneal abrasions to ensure complete healing without infection or scarring. Contact lens wearers, patients with patched eyes, or those with bandage contact lenses should be re-evaluated by ophthalmology within 24 hours. Central or large abrasions also warrant ophthalmologic follow-up within 24 hours, while smaller peripheral abrasions may be rechecked within 48–72 hours.
Essential Clinical Cautions and Common Errors
Clinicians must always carefully evaluate for penetrating globe injuries and signs of infection. Patients should never be discharged with topical anesthetics, as these agents are toxic to the corneal epithelium and delay healing, despite limited evidence suggesting dilute formulations may be safe. Mydriatic agents should not be used in patients with a history of glaucoma. Contact lens use should not be resumed until the patient has been evaluated and cleared by ophthalmology.
- Published on
Emergency and Acute Medicine – Corneal Burn
Definition and Mechanisms of Injury
A corneal burn results from inappropriate exposure of the cornea to chemical agents, extreme heat or cold, electrical current, or radiant energy, leading to injury of the corneal tissue and frequently extending to adjacent ocular structures. The severity of injury is determined by the duration of exposure, the nature of the offending agent, its concentration, and in chemical injuries, the pH and ionic properties of the solution.
Alkali burns are particularly dangerous because they cause an immediate rise in ocular pH and are highly lipid soluble, allowing rapid penetration through ocular tissues. Without prompt intervention, alkalis continue to penetrate deeper layers, with significant injury occurring in less than one minute. Calcium-based alkalis are a notable exception, as they penetrate less effectively due to soap formation; although they may cause marked corneal opacification, their overall prognosis is often better than that of other alkali burns. Acid burns cause rapid coagulation of corneal epithelial proteins, leading to opacification. This coagulation creates a barrier that limits deeper penetration, except in the case of hydrofluoric acid, which is lipophilic and behaves more like an alkali, penetrating rapidly and causing severe injury.
Thermal burns generally affect the eyelids more than the globe because of reflex blinking and the Bell phenomenon, in which the eyes roll upward and outward. When the cornea is involved, injury severity depends on the duration and intensity of heat exposure. Electrical injuries occur when current passes through the head with an entry point at or near the eye. Radiation injuries result from ultraviolet light exposure to the cornea.
Etiology and Sources of Exposure
Common alkali agents include ammonia found in fertilizers, refrigerants, household ammonia, and cleaning agents; potassium hydroxide; magnesium hydroxide from sparklers, flares, and fireworks; sodium hydroxide in drain cleaners; and lime compounds used in cement, plaster, mortar, and whitewash. Motor vehicle airbag deployment can also release nonspecific alkali during inflation.
Acid exposures include sulfuric acid from car batteries and toilet cleaners, sulfurous acid used as food preservatives, acetic acid in vinegar, bleach, and hydrofluoric acid used in glass etching, brick cleaning, metal electropolishing, brewery fermentation control, and rust removal. Thermal injuries may result from hot liquids, molten metal, flames, hot smoke or gases, flash burns, steam, or cigarette burns. Radiation injuries are associated with sun lamps, tanning booths, high-altitude sunlight, reflected ultraviolet light from snow or water, and arc welding. In pediatric cases, the possibility of abuse or neglect must always be considered.
Clinical Presentation
Patients often present with severe eye pain, photophobia, excessive tearing, and a foreign body sensation. Conjunctival injection, corneal edema, corneal opacification, and reduced visual acuity are common. More severe findings include limbal blanching, lens opacification, vesicle formation with clear or hemorrhagic fluid in hypothermal injuries, and necrosis of the iris or ciliary body.
The history should focus on identifying the type of exposure and, when possible, inspection of any containers brought by the patient to determine active and inactive ingredients. The vehicle of exposure should be clarified, as aerosols are common and propellants may cause intraocular foreign bodies or perforation. Duration of exposure, time to irrigation, symptom onset, pre-existing visual impairment, protective eyewear use, contact lens use, and treatments initiated prior to arrival should be documented.
Physical Examination and Diagnostic Evaluation
A complete ocular examination should be performed after adequate irrigation. Visual acuity should be assessed first, followed by inspection of the cornea, conjunctivae, and limbus under bright white light. Slit-lamp examination is essential to evaluate anterior segment inflammation. Fluorescein staining helps identify corneal epithelial defects, including punctate lesions with a discrete inferior border typical of ultraviolet radiation burns, and can be used to detect perforation with the Seidel test. Lens clarity and fundus appearance should be assessed when possible, and intraocular pressure should be measured, particularly in delayed presentations. Examination of the eyelids and eyelashes is important to identify retained particulate matter. In acid or alkali burns, ocular pH should be measured using litmus paper or pH indicator strips placed in the inferior conjunctival fornix.
In children, handheld slit lamps and Wood lamps are particularly useful to facilitate examination.
Differential Diagnosis
Conditions that may resemble corneal burns include viral keratitis, corneal ulcer, corneal erosion syndrome, corneal foreign body, corneal abrasion, and hypothermal injury.
Prehospital and Initial Management
At the scene, immediate irrigation for 15–30 minutes is critical unless other life-threatening conditions require urgent transport. Whenever possible, the offending substance container should be brought to the hospital. Continuous irrigation with water or normal saline should be maintained during transport.
Initial stabilization depends on the type of exposure. For unknown chemical exposures, acid or alkali injury should be assumed, and irrigation initiated with any available diluting fluid, preferably water or normal saline. Thermal injuries should be managed with cool, moist dressings and overlying ice packs.
Emergency Department Treatment
For chemical exposures, including alkalis, acids, and mace, continuous irrigation is performed until a target pH of 7.3–7.5 is achieved, typically requiring 1–2 liters of fluid over 30–60 minutes using a Morgan lens. Ocular pH should be checked every 30 minutes, with pH paper placed in the inferior conjunctival fornix, and rechecked at 5 and 30 minutes after irrigation to confirm normalization. Topical anesthetics such as proparacaine may be required to facilitate irrigation. The fornices must be carefully inspected with the eye moved through full range of motion to ensure complete removal of particulate material.
Prophylactic topical antibiotics targeting Staphylococcus and Pseudomonas species are recommended until epithelial healing is complete, commonly using gentamicin ointment in combination with erythromycin or bacitracin. Cycloplegic agents such as cyclopentolate or atropine are used to reduce pain and prevent posterior synechiae. Oral analgesics are often required. If intraocular pressure is elevated, immediate ophthalmologic consultation is necessary, and treatment may include acetazolamide and topical timolol. Topical corticosteroids may be used to control anterior uveitis only after consultation with ophthalmology. Eye patching and surgical intervention may be required in cases of corneal penetration. Mild injuries warrant ophthalmology consultation by phone, while all moderate to severe injuries require immediate ophthalmologic evaluation or transfer to a specialized eye center. Hydrofluoric acid burns require standard treatment plus 1% calcium gluconate eye drops and admission for systemic analgesia.
Thermal injuries are managed with frequent moist dressing changes, topical antibiotics four times daily, generous lubrication, and moisture chambers when eyelid injury is extensive. Steroids may be used for short durations under ophthalmologic guidance. Any second- or third-degree eyelid burn requires ophthalmology consultation. Cigarette ash or hot liquid splashes usually cause superficial epithelial injury and are treated similarly to corneal abrasions. Electrical injuries require irrigation, wound care, antibiotic ointment, cycloplegics if uveitis is present, and adequate analgesia. Radiation injuries are treated with topical anesthetics for examination, short-acting cycloplegics, antibiotic ointment, and oral opioids if pain is severe.
Medications
Common treatments include artificial tears, cycloplegics such as atropine, cyclopentolate, homatropine, or tropicamide, topical antibiotics including bacitracin, erythromycin, gentamicin, sulfacetamide, ciprofloxacin, and tobramycin, and short-term topical anesthetics for in-hospital use only.
Disposition and Follow-Up
Admission is indicated for patients with intractable pain, elevated intraocular pressure, corneal penetration requiring surgical intervention, hydrofluoric acid burns requiring observation, or suspected child abuse. All mild corneal burns may be discharged once stabilized. Mandatory ophthalmology follow-up within 12–24 hours is required for all patients and should be arranged prior to discharge.
Key Management Principles and Safety Considerations
In chemical exposures, ocular examination should be delayed until adequate irrigation has been completed. Any patient with a corneal epithelial defect requires ophthalmologic follow-up within 12–24 hours. Topical anesthetics should never be prescribed for outpatient use, as they delay epithelial healing and increase the risk of serious complications.
Definition and Mechanisms of Injury
A corneal burn results from inappropriate exposure of the cornea to chemical agents, extreme heat or cold, electrical current, or radiant energy, leading to injury of the corneal tissue and frequently extending to adjacent ocular structures. The severity of injury is determined by the duration of exposure, the nature of the offending agent, its concentration, and in chemical injuries, the pH and ionic properties of the solution.
Alkali burns are particularly dangerous because they cause an immediate rise in ocular pH and are highly lipid soluble, allowing rapid penetration through ocular tissues. Without prompt intervention, alkalis continue to penetrate deeper layers, with significant injury occurring in less than one minute. Calcium-based alkalis are a notable exception, as they penetrate less effectively due to soap formation; although they may cause marked corneal opacification, their overall prognosis is often better than that of other alkali burns. Acid burns cause rapid coagulation of corneal epithelial proteins, leading to opacification. This coagulation creates a barrier that limits deeper penetration, except in the case of hydrofluoric acid, which is lipophilic and behaves more like an alkali, penetrating rapidly and causing severe injury.
Thermal burns generally affect the eyelids more than the globe because of reflex blinking and the Bell phenomenon, in which the eyes roll upward and outward. When the cornea is involved, injury severity depends on the duration and intensity of heat exposure. Electrical injuries occur when current passes through the head with an entry point at or near the eye. Radiation injuries result from ultraviolet light exposure to the cornea.
Etiology and Sources of Exposure
Common alkali agents include ammonia found in fertilizers, refrigerants, household ammonia, and cleaning agents; potassium hydroxide; magnesium hydroxide from sparklers, flares, and fireworks; sodium hydroxide in drain cleaners; and lime compounds used in cement, plaster, mortar, and whitewash. Motor vehicle airbag deployment can also release nonspecific alkali during inflation.
Acid exposures include sulfuric acid from car batteries and toilet cleaners, sulfurous acid used as food preservatives, acetic acid in vinegar, bleach, and hydrofluoric acid used in glass etching, brick cleaning, metal electropolishing, brewery fermentation control, and rust removal. Thermal injuries may result from hot liquids, molten metal, flames, hot smoke or gases, flash burns, steam, or cigarette burns. Radiation injuries are associated with sun lamps, tanning booths, high-altitude sunlight, reflected ultraviolet light from snow or water, and arc welding. In pediatric cases, the possibility of abuse or neglect must always be considered.
Clinical Presentation
Patients often present with severe eye pain, photophobia, excessive tearing, and a foreign body sensation. Conjunctival injection, corneal edema, corneal opacification, and reduced visual acuity are common. More severe findings include limbal blanching, lens opacification, vesicle formation with clear or hemorrhagic fluid in hypothermal injuries, and necrosis of the iris or ciliary body.
The history should focus on identifying the type of exposure and, when possible, inspection of any containers brought by the patient to determine active and inactive ingredients. The vehicle of exposure should be clarified, as aerosols are common and propellants may cause intraocular foreign bodies or perforation. Duration of exposure, time to irrigation, symptom onset, pre-existing visual impairment, protective eyewear use, contact lens use, and treatments initiated prior to arrival should be documented.
Physical Examination and Diagnostic Evaluation
A complete ocular examination should be performed after adequate irrigation. Visual acuity should be assessed first, followed by inspection of the cornea, conjunctivae, and limbus under bright white light. Slit-lamp examination is essential to evaluate anterior segment inflammation. Fluorescein staining helps identify corneal epithelial defects, including punctate lesions with a discrete inferior border typical of ultraviolet radiation burns, and can be used to detect perforation with the Seidel test. Lens clarity and fundus appearance should be assessed when possible, and intraocular pressure should be measured, particularly in delayed presentations. Examination of the eyelids and eyelashes is important to identify retained particulate matter. In acid or alkali burns, ocular pH should be measured using litmus paper or pH indicator strips placed in the inferior conjunctival fornix.
In children, handheld slit lamps and Wood lamps are particularly useful to facilitate examination.
Differential Diagnosis
Conditions that may resemble corneal burns include viral keratitis, corneal ulcer, corneal erosion syndrome, corneal foreign body, corneal abrasion, and hypothermal injury.
Prehospital and Initial Management
At the scene, immediate irrigation for 15–30 minutes is critical unless other life-threatening conditions require urgent transport. Whenever possible, the offending substance container should be brought to the hospital. Continuous irrigation with water or normal saline should be maintained during transport.
Initial stabilization depends on the type of exposure. For unknown chemical exposures, acid or alkali injury should be assumed, and irrigation initiated with any available diluting fluid, preferably water or normal saline. Thermal injuries should be managed with cool, moist dressings and overlying ice packs.
Emergency Department Treatment
For chemical exposures, including alkalis, acids, and mace, continuous irrigation is performed until a target pH of 7.3–7.5 is achieved, typically requiring 1–2 liters of fluid over 30–60 minutes using a Morgan lens. Ocular pH should be checked every 30 minutes, with pH paper placed in the inferior conjunctival fornix, and rechecked at 5 and 30 minutes after irrigation to confirm normalization. Topical anesthetics such as proparacaine may be required to facilitate irrigation. The fornices must be carefully inspected with the eye moved through full range of motion to ensure complete removal of particulate material.
Prophylactic topical antibiotics targeting Staphylococcus and Pseudomonas species are recommended until epithelial healing is complete, commonly using gentamicin ointment in combination with erythromycin or bacitracin. Cycloplegic agents such as cyclopentolate or atropine are used to reduce pain and prevent posterior synechiae. Oral analgesics are often required. If intraocular pressure is elevated, immediate ophthalmologic consultation is necessary, and treatment may include acetazolamide and topical timolol. Topical corticosteroids may be used to control anterior uveitis only after consultation with ophthalmology. Eye patching and surgical intervention may be required in cases of corneal penetration. Mild injuries warrant ophthalmology consultation by phone, while all moderate to severe injuries require immediate ophthalmologic evaluation or transfer to a specialized eye center. Hydrofluoric acid burns require standard treatment plus 1% calcium gluconate eye drops and admission for systemic analgesia.
Thermal injuries are managed with frequent moist dressing changes, topical antibiotics four times daily, generous lubrication, and moisture chambers when eyelid injury is extensive. Steroids may be used for short durations under ophthalmologic guidance. Any second- or third-degree eyelid burn requires ophthalmology consultation. Cigarette ash or hot liquid splashes usually cause superficial epithelial injury and are treated similarly to corneal abrasions. Electrical injuries require irrigation, wound care, antibiotic ointment, cycloplegics if uveitis is present, and adequate analgesia. Radiation injuries are treated with topical anesthetics for examination, short-acting cycloplegics, antibiotic ointment, and oral opioids if pain is severe.
Medications
Common treatments include artificial tears, cycloplegics such as atropine, cyclopentolate, homatropine, or tropicamide, topical antibiotics including bacitracin, erythromycin, gentamicin, sulfacetamide, ciprofloxacin, and tobramycin, and short-term topical anesthetics for in-hospital use only.
Disposition and Follow-Up
Admission is indicated for patients with intractable pain, elevated intraocular pressure, corneal penetration requiring surgical intervention, hydrofluoric acid burns requiring observation, or suspected child abuse. All mild corneal burns may be discharged once stabilized. Mandatory ophthalmology follow-up within 12–24 hours is required for all patients and should be arranged prior to discharge.
Key Management Principles and Safety Considerations
In chemical exposures, ocular examination should be delayed until adequate irrigation has been completed. Any patient with a corneal epithelial defect requires ophthalmologic follow-up within 12–24 hours. Topical anesthetics should never be prescribed for outpatient use, as they delay epithelial healing and increase the risk of serious complications.
- Published on
Emergency And Acute Medicine – Cystic Fibrosis
Foundational Overview
Cystic fibrosis is caused by a defect in the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR functions as an ATP-regulated chloride channel that modulates chloride and sodium transport across epithelial cell surfaces. Dysfunction leads to abnormal electrolyte movement in exocrine glands and secretory epithelia. The result is thick, viscous secretions, impaired mucociliary clearance, recurrent pulmonary infections, and progressive obstructive lung disease. Exocrine pancreatic insufficiency causes malabsorption, while chronic sinus disease is common.
Cystic fibrosis occurs in approximately 1 in 3,600 live births in the White population, 1 in 29,000 in African American individuals, and 1 in 6,500 in Hispanic individuals. About 30% of cases are detected through newborn screening, and 75% are diagnosed within the first two years of life. Approximately 30,000 children and young adults in the United States live with cystic fibrosis. Median life expectancy in the U.S. is about 40 years, with 40% of patients older than 18 years. Roughly 10 million Americans are asymptomatic carriers. Sixteen percent of lung transplants in the U.S. are performed for cystic fibrosis–related lung disease.
Predisposing Factors
Cystic fibrosis is an autosomal recessive genetic disorder involving the CFTR gene on the long arm of chromosome 7. Numerous mutations exist, resulting in variable phenotypes. Classic disease is most commonly associated with homozygous ΔF508 mutations. Cystic fibrosis remains the most common lethal genetic disease in the United States.
Infectious Contributors And Pathogenesis
Patients are predisposed to chronic and recurrent pulmonary infections, often involving multidrug-resistant organisms. Common pathogens include methicillin-sensitive and methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa (with prevalence increasing with age and chronic infection in more than 70% of adults), Haemophilus influenzae, Stenotrophomonas maltophilia, and Achromobacter xylosoxidans.
Burkholderia cepacia occurs in approximately 3% of patients and is associated with rapid clinical deterioration. Nontuberculous mycobacteria, including Mycobacterium avium complex and Mycobacterium abscessus, and fungal pathogens such as Aspergillus are also encountered.
Clinical Manifestations
General findings include failure to thrive, recurrent respiratory infections, anasarca in infancy, and a characteristic salty taste of the skin.
Head and neck involvement includes nasal polyps, severe headaches from sinusitis, and recurrent otitis media.
Pulmonary features include persistent cough that progresses from dry to productive, recurrent bronchiolitis or pneumonitis in the first year of life, wheezing, hemoptysis, pneumonia, chronic bronchitis, bronchiectasis, respiratory distress, pneumothorax, and pneumomediastinum. Pulmonary complications are the most common cause of hospitalization.
Cardiac complications include congestive heart failure, cor pulmonale, and pulmonary hypertension.
Gastrointestinal manifestations include abdominal pain, meconium ileus, distal intestinal obstructive syndrome (DIOS, also called meconium ileus equivalent), gastroesophageal reflux, cholelithiasis, pancreatitis, pancreatic insufficiency, ileocecal intussusception, foul-smelling fatty stools, jaundice or cirrhosis, rectal prolapse, hematemesis, and small-intestinal bacterial overgrowth.
Musculoskeletal and systemic findings include bone pain, edema or joint effusions, decreased cortical bone thickness, and recurrent venous thrombosis. Cardiorespiratory failure is the leading cause of death.
Essential Diagnostic Evaluation
Initial confirmation relies on sweat chloride testing. DNA analysis is indicated if sweat testing is equivocal. Nasal potential difference testing is reserved for cases where DNA analysis is inconclusive.
Diagnostic Studies And Interpretation
The sweat chloride test is diagnostic when chloride concentration exceeds 60 mEq/L in the presence of classic symptoms. Stool studies may demonstrate decreased elastase, trypsin, or chymotrypsin, and increased fat on 72-hour fecal fat testing. Immunoreactive trypsin (IRT) screening identifies increased risk but may yield false positives or negatives.
DNA analysis detects approximately 90% of cystic fibrosis chromosomes and is positive when two abnormal CFTR genes are present. Genotyping alone cannot establish the diagnosis, as more than 1,300 CFTR mutations exist and modifying mutations may attenuate disease severity.
Laboratory evaluation may reveal thrombocytopenia, hyponatremic hypochloremic metabolic alkalosis, hyperglycemia or new-onset diabetes in adolescents and adults (with ketoacidosis being rare), and abnormal liver function tests or prolonged prothrombin time in the setting of liver disease or bleeding. Arterial blood gases may show hypoxemia and metabolic alkalosis. Sputum cultures often reveal chronic pseudomonal colonization.
Specialized studies include nasal potential difference testing, which is complex and time-consuming, and semen analysis demonstrating azoospermia in affected males.
Imaging findings on chest radiography include hyperaeration, peribronchial thickening, atelectasis, hilar lymphadenopathy, pneumothorax, pneumomediastinum, bronchiectasis, and blebs. Chest CT better defines bronchiectasis and bleb disease. Abdominal imaging is indicated for pain, vomiting, or distention to evaluate for DIOS or intussusception. Barium enema is used when intussusception is suspected. Routine sinus radiographs are of limited value, as they are almost always abnormal; CT imaging is required for operative planning.
Bronchoalveolar lavage may demonstrate neutrophilic inflammation but is unnecessary when pulmonary disease is clinically evident.
Conditions To Exclude
Respiratory alternatives include asthma, recurrent pneumonia, bronchiectasis from other causes, pertussis, immunodeficiency, foreign body aspiration, alpha-1 antitrypsin deficiency, and ciliary dyskinesia.
Gastrointestinal mimics include chronic diarrhea, gastroenteritis, and milk allergy.
Other causes of elevated sweat electrolytes include fucosidosis, glycogen storage disease type I, mucopolysaccharidoses, hypothyroidism, vasopressin-resistant diabetes insipidus, adrenal insufficiency, familial cholestasis or hypoparathyroidism, malnutrition, ectodermal dysplasia, atopic dermatitis, and prostaglandin E1 infusion.
Emergency And Acute Care Management
Prehospital considerations include transcutaneous pacing for unstable type II second-degree or third-degree heart block. Atropine should be avoided in type II second-degree block due to risk of progression to complete heart block.
Emergency department priorities focus on stabilization of airway, breathing, and circulation, with correction of fluid, electrolyte, glucose, and respiratory abnormalities. Bronchodilators and steroids are used for wheezing. Small pneumothoraces under 5–10% may be observed, while larger ones require thoracostomy. Early consultation with the patient’s cystic fibrosis specialist is essential.
Right-sided heart failure is treated with diuretics. Hemoptysis requires evaluation of coagulation status and transfusion as indicated. Ventilatory support may be necessary in severe respiratory failure.
DIOS often requires surgical intervention. Hematemesis is managed with packed red blood cells, correction of coagulopathy, and early endoscopic consultation. Intussusception is treated with air or barium enema, with surgery if unsuccessful. Rectal prolapse is manually reduced, with surgical consultation as needed.
Respiratory care includes aggressive pulmonary toilet, chest physiotherapy, mucus-thinning inhaled agents, and antibiotics tailored to culture and sensitivity results. Treatment regimens vary based on organism profile, including coverage for MSSA, MRSA, Pseudomonas aeruginosa, Burkholderia cepacia, and Haemophilus influenzae. Ciprofloxacin may replace aminoglycosides when organisms are sensitive.
Disease-specific therapies include CFTR modulators such as ivacaftor to improve protein function, nebulized hypertonic saline to restore airway surface liquid, and dornase alfa to reduce mucus viscosity. Adjunctive strategies include high-dose ibuprofen for anti-inflammatory effects, inhaled antibiotics, nutritional optimization, exercise programs, and consideration of lung transplantation in advanced disease.
Pharmacologic Therapy
Antibiotic regimens include aminoglycosides, antipseudomonal penicillins, cephalosporins, carbapenems, vancomycin, and trimethoprim–sulfamethoxazole, dosed carefully due to altered pharmacokinetics in undernourished patients. Close monitoring of drug levels, particularly with aminoglycosides, is essential.
Disposition And Follow-Up
Hospital admission is required for pulmonary exacerbations with significant decline from baseline, hypoxemia, resistant organisms, or failure of outpatient therapy, as well as pneumothorax, hemoptysis, hematemesis, intussusception, unexplained abdominal pain, bowel obstruction, or hyperglycemia.
Discharge requires close follow-up to review culture sensitivities and adjust therapy. Patients should avoid excessive heat exposure and may require oral salt supplementation during periods of heavy sweating.
Care Coordination And Long-Term Planning
All patients should be followed by a specialized cystic fibrosis pulmonary center. Acute exacerbations warrant early consultation. Long-term care requires a multidisciplinary team approach incorporating airway clearance, antibiotics, nutritional support, pancreatic enzyme replacement, and exercise programs.
Key Clinical Insights And Common Pitfalls
In cystic fibrosis patients with acute respiratory distress, pneumothorax must always be considered and promptly evaluated with chest imaging. In those presenting with abdominal pain or vomiting, distal intestinal obstructive syndrome and intussusception should remain high on the differential.
Foundational Overview
Cystic fibrosis is caused by a defect in the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR functions as an ATP-regulated chloride channel that modulates chloride and sodium transport across epithelial cell surfaces. Dysfunction leads to abnormal electrolyte movement in exocrine glands and secretory epithelia. The result is thick, viscous secretions, impaired mucociliary clearance, recurrent pulmonary infections, and progressive obstructive lung disease. Exocrine pancreatic insufficiency causes malabsorption, while chronic sinus disease is common.
Cystic fibrosis occurs in approximately 1 in 3,600 live births in the White population, 1 in 29,000 in African American individuals, and 1 in 6,500 in Hispanic individuals. About 30% of cases are detected through newborn screening, and 75% are diagnosed within the first two years of life. Approximately 30,000 children and young adults in the United States live with cystic fibrosis. Median life expectancy in the U.S. is about 40 years, with 40% of patients older than 18 years. Roughly 10 million Americans are asymptomatic carriers. Sixteen percent of lung transplants in the U.S. are performed for cystic fibrosis–related lung disease.
Predisposing Factors
Cystic fibrosis is an autosomal recessive genetic disorder involving the CFTR gene on the long arm of chromosome 7. Numerous mutations exist, resulting in variable phenotypes. Classic disease is most commonly associated with homozygous ΔF508 mutations. Cystic fibrosis remains the most common lethal genetic disease in the United States.
Infectious Contributors And Pathogenesis
Patients are predisposed to chronic and recurrent pulmonary infections, often involving multidrug-resistant organisms. Common pathogens include methicillin-sensitive and methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa (with prevalence increasing with age and chronic infection in more than 70% of adults), Haemophilus influenzae, Stenotrophomonas maltophilia, and Achromobacter xylosoxidans.
Burkholderia cepacia occurs in approximately 3% of patients and is associated with rapid clinical deterioration. Nontuberculous mycobacteria, including Mycobacterium avium complex and Mycobacterium abscessus, and fungal pathogens such as Aspergillus are also encountered.
Clinical Manifestations
General findings include failure to thrive, recurrent respiratory infections, anasarca in infancy, and a characteristic salty taste of the skin.
Head and neck involvement includes nasal polyps, severe headaches from sinusitis, and recurrent otitis media.
Pulmonary features include persistent cough that progresses from dry to productive, recurrent bronchiolitis or pneumonitis in the first year of life, wheezing, hemoptysis, pneumonia, chronic bronchitis, bronchiectasis, respiratory distress, pneumothorax, and pneumomediastinum. Pulmonary complications are the most common cause of hospitalization.
Cardiac complications include congestive heart failure, cor pulmonale, and pulmonary hypertension.
Gastrointestinal manifestations include abdominal pain, meconium ileus, distal intestinal obstructive syndrome (DIOS, also called meconium ileus equivalent), gastroesophageal reflux, cholelithiasis, pancreatitis, pancreatic insufficiency, ileocecal intussusception, foul-smelling fatty stools, jaundice or cirrhosis, rectal prolapse, hematemesis, and small-intestinal bacterial overgrowth.
Musculoskeletal and systemic findings include bone pain, edema or joint effusions, decreased cortical bone thickness, and recurrent venous thrombosis. Cardiorespiratory failure is the leading cause of death.
Essential Diagnostic Evaluation
Initial confirmation relies on sweat chloride testing. DNA analysis is indicated if sweat testing is equivocal. Nasal potential difference testing is reserved for cases where DNA analysis is inconclusive.
Diagnostic Studies And Interpretation
The sweat chloride test is diagnostic when chloride concentration exceeds 60 mEq/L in the presence of classic symptoms. Stool studies may demonstrate decreased elastase, trypsin, or chymotrypsin, and increased fat on 72-hour fecal fat testing. Immunoreactive trypsin (IRT) screening identifies increased risk but may yield false positives or negatives.
DNA analysis detects approximately 90% of cystic fibrosis chromosomes and is positive when two abnormal CFTR genes are present. Genotyping alone cannot establish the diagnosis, as more than 1,300 CFTR mutations exist and modifying mutations may attenuate disease severity.
Laboratory evaluation may reveal thrombocytopenia, hyponatremic hypochloremic metabolic alkalosis, hyperglycemia or new-onset diabetes in adolescents and adults (with ketoacidosis being rare), and abnormal liver function tests or prolonged prothrombin time in the setting of liver disease or bleeding. Arterial blood gases may show hypoxemia and metabolic alkalosis. Sputum cultures often reveal chronic pseudomonal colonization.
Specialized studies include nasal potential difference testing, which is complex and time-consuming, and semen analysis demonstrating azoospermia in affected males.
Imaging findings on chest radiography include hyperaeration, peribronchial thickening, atelectasis, hilar lymphadenopathy, pneumothorax, pneumomediastinum, bronchiectasis, and blebs. Chest CT better defines bronchiectasis and bleb disease. Abdominal imaging is indicated for pain, vomiting, or distention to evaluate for DIOS or intussusception. Barium enema is used when intussusception is suspected. Routine sinus radiographs are of limited value, as they are almost always abnormal; CT imaging is required for operative planning.
Bronchoalveolar lavage may demonstrate neutrophilic inflammation but is unnecessary when pulmonary disease is clinically evident.
Conditions To Exclude
Respiratory alternatives include asthma, recurrent pneumonia, bronchiectasis from other causes, pertussis, immunodeficiency, foreign body aspiration, alpha-1 antitrypsin deficiency, and ciliary dyskinesia.
Gastrointestinal mimics include chronic diarrhea, gastroenteritis, and milk allergy.
Other causes of elevated sweat electrolytes include fucosidosis, glycogen storage disease type I, mucopolysaccharidoses, hypothyroidism, vasopressin-resistant diabetes insipidus, adrenal insufficiency, familial cholestasis or hypoparathyroidism, malnutrition, ectodermal dysplasia, atopic dermatitis, and prostaglandin E1 infusion.
Emergency And Acute Care Management
Prehospital considerations include transcutaneous pacing for unstable type II second-degree or third-degree heart block. Atropine should be avoided in type II second-degree block due to risk of progression to complete heart block.
Emergency department priorities focus on stabilization of airway, breathing, and circulation, with correction of fluid, electrolyte, glucose, and respiratory abnormalities. Bronchodilators and steroids are used for wheezing. Small pneumothoraces under 5–10% may be observed, while larger ones require thoracostomy. Early consultation with the patient’s cystic fibrosis specialist is essential.
Right-sided heart failure is treated with diuretics. Hemoptysis requires evaluation of coagulation status and transfusion as indicated. Ventilatory support may be necessary in severe respiratory failure.
DIOS often requires surgical intervention. Hematemesis is managed with packed red blood cells, correction of coagulopathy, and early endoscopic consultation. Intussusception is treated with air or barium enema, with surgery if unsuccessful. Rectal prolapse is manually reduced, with surgical consultation as needed.
Respiratory care includes aggressive pulmonary toilet, chest physiotherapy, mucus-thinning inhaled agents, and antibiotics tailored to culture and sensitivity results. Treatment regimens vary based on organism profile, including coverage for MSSA, MRSA, Pseudomonas aeruginosa, Burkholderia cepacia, and Haemophilus influenzae. Ciprofloxacin may replace aminoglycosides when organisms are sensitive.
Disease-specific therapies include CFTR modulators such as ivacaftor to improve protein function, nebulized hypertonic saline to restore airway surface liquid, and dornase alfa to reduce mucus viscosity. Adjunctive strategies include high-dose ibuprofen for anti-inflammatory effects, inhaled antibiotics, nutritional optimization, exercise programs, and consideration of lung transplantation in advanced disease.
Pharmacologic Therapy
Antibiotic regimens include aminoglycosides, antipseudomonal penicillins, cephalosporins, carbapenems, vancomycin, and trimethoprim–sulfamethoxazole, dosed carefully due to altered pharmacokinetics in undernourished patients. Close monitoring of drug levels, particularly with aminoglycosides, is essential.
Disposition And Follow-Up
Hospital admission is required for pulmonary exacerbations with significant decline from baseline, hypoxemia, resistant organisms, or failure of outpatient therapy, as well as pneumothorax, hemoptysis, hematemesis, intussusception, unexplained abdominal pain, bowel obstruction, or hyperglycemia.
Discharge requires close follow-up to review culture sensitivities and adjust therapy. Patients should avoid excessive heat exposure and may require oral salt supplementation during periods of heavy sweating.
Care Coordination And Long-Term Planning
All patients should be followed by a specialized cystic fibrosis pulmonary center. Acute exacerbations warrant early consultation. Long-term care requires a multidisciplinary team approach incorporating airway clearance, antibiotics, nutritional support, pancreatic enzyme replacement, and exercise programs.
Key Clinical Insights And Common Pitfalls
In cystic fibrosis patients with acute respiratory distress, pneumothorax must always be considered and promptly evaluated with chest imaging. In those presenting with abdominal pain or vomiting, distal intestinal obstructive syndrome and intussusception should remain high on the differential.
