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Emergency and Acute Medicine – Pediatric Asthma
Clinical Overview
Pediatric asthma is a common inflammatory airway disease affecting about 2.7 million children (<18 years) in the united states and accounts for roughly 850,000 emergency department visits annually. viral-driven airway inflammation commonly triggers bronchoconstriction, which is amplified by hyperreactivity inflammatory mediators. resulting airflow obstruction increases resistance causes gas trapping, driven mucosal edema, bronchospasm, mucus plugging. infants are particularly prone to respiratory failure because of higher peripheral resistance, reduced elastic recoil with earlier closure, an unstable rib cage, a mechanically disadvantaged diaphragm. risk influenced family history allergy early injury or vulnerability such as bronchopulmonary dysplasia, prior pneumonia, intubation, croup, reflux, passive smoke exposure; reactions foods medications other allergic conditions also support atopic predisposition. environmental exposures including pets, cigarette smoke, carpets, dust can precipitate worsen symptoms.< />pan>
Common Causes And Triggers
Exacerbations are often precipitated by infection, most commonly viral but sometimes bacterial. Environmental allergens and irritants are frequent contributors, including pollens, grasses, mold, house dust mites, and animal dander, as well as airborne chemicals such as chlorine or ammonia and food-related additives. Smoke, pollutants, gases, and aerosols may aggravate bronchospasm. Exercise, cold weather, and emotional stressors (including phobias) can provoke symptoms. Medication-related triggers include beta-blockers, aspirin, and NSAIDs.
Clinical Features
Children may present with fatigue or somnolence, diaphoresis, agitation, hypoxia or cyanosis, tachycardia, dehydration, and pulsus paradoxus. Respiratory findings include wheezing, rales, or rhonchi; acute or chronic cough; tachypnea; chest tightness; dyspnea with a prolonged expiratory phase; retractions with accessory muscle use and nasal flaring; and signs of hyperinflation. Many have a history of recurrent episodes and chronic activity restriction. Potential complications include recurrent pneumonia or bronchitis, atelectasis, pneumothorax or pneumomediastinum, and in severe cases respiratory distress, respiratory failure, or death.
History And Examination
History should focus on precipitating events and known triggers, symptom duration and progression, comorbid illness, and prior disease severity markers including previous hospitalizations, prior intubations or ICU care, and current regular or intermittent medications. Examination should include vital signs with pulse oximetry and a focused respiratory assessment. Wheeze intensity can be misleading; absent wheezing may indicate critically reduced airflow with diminished breath sounds. Look for hypoxia through skin and nail bed color changes and assess for fatigue or impending failure by noting accessory muscle use or retractions, lethargy, confusion, somnolence, or exhaustion.
Essential Evaluation
Diagnosis is clinical and relies on history and physical examination. Ventilation is assessed by observing work of breathing (retractions and accessory muscle use) and by auscultation for air exchange. Clinical response to bronchodilators should be tracked in the current episode and interpreted in the context of prior episodes. Alternative diagnoses must be considered and excluded. Initial pulse oximetry is important; an oxygen saturation below 91% at sea level correlates with more significant illness and is associated with admission risk, relapse, and a more prolonged course. Peak flow measurement can help in cooperative children, typically those older than five years; values below 50–70% of predicted suggest moderate to severe obstruction, 70–90% aligns with mild to moderate disease, and above 90% is considered normal.
Tests And Imaging
Arterial blood gas testing is not routine and is not mandatory; it can supplement oximetry for oxygenation assessment and support clinical judgment about ventilation when needed. CBC may be obtained as a nonspecific marker when infection is a concern. Theophylline levels are relevant only if a child is taking theophylline, though this therapy is not recommended. Chest radiography is considered selectively to evaluate for infiltrates, bronchial wall thickening, or hyperexpansion, and is especially considered in infants under one year to help exclude foreign body aspiration or atelectasis, in a first episode of significant wheezing to help assess chronicity and alternative diagnoses, in worsening distress or poor response to therapy, in respiratory distress or failure, and in shortness of breath without wheeze.
Differential Diagnosis
Infectious or inflammatory mimics include bronchiolitis, which can be difficult to distinguish clinically aside from age and history, and pneumonia of viral, bacterial, chemical, or hypersensitivity origin. Aspiration, deep neck or mediastinal abscesses or masses, and anaphylaxis must be considered. Structural and anatomic problems include pneumothorax and foreign body aspiration. Vascular causes include tracheal compression from vascular anomalies, pulmonary embolism, and heart failure. Congenital and chronic disorders include cystic fibrosis, tracheoesophageal fistula, bronchogenic cysts, and congenital heart disease. Other considerations include intoxication or medication effects, metabolic acidosis, neoplasm, vocal cord dysfunction, pulmonary edema (cardiogenic or noncardiogenic), and gastroesophageal reflux.
Prehospital Care
Field care emphasizes oxygen and continuous oxygen saturation monitoring, nebulized beta-agonist therapy such as albuterol, and rapid transport with clear communication to the receiving emergency team. Intubation is required for respiratory failure or profound fatigue. Intravenous fluids should be given when dehydration is evident.
Initial Stabilization In The ED
The immediate goal is to maintain oxygen saturation above 90–95% while initiating inhaled beta-agonist therapy. Intubation is indicated for respiratory failure. If dehydration is present, administer a 20 mL/kg bolus of 0.9% normal saline.
Emergency Department Management
Evaluate for impending respiratory failure, focusing on cyanosis, severe anxiety or irritability, lethargy or somnolence, fatigue, persistent tachypnea, markedly reduced air entry, and poor ventilation. Oxygen should be titrated to maintain saturations above 95% at sea level. Albuterol is the primary bronchodilator and may be given frequently or continuously in severe exacerbations. Levalbuterol may be associated with fewer side effects and may allow less frequent dosing in some children. Ipratropium bromide can be added as an adjunct, with the best benefit seen when combined with the first three beta-agonist treatments in moderate to severe presentations. Systemic steroids are recommended, using oral administration for moderate exacerbations when oral intake is possible and intravenous dosing for severe illness or inability to tolerate oral medications; a single dose of dexamethasone may be comparable to more traditional steroid courses. Subcutaneous epinephrine or terbutaline is reserved for severe or refractory cases and is used infrequently. Magnesium sulfate may help in severe asthma that persists despite standard therapy. If intubation is required, ketamine is a useful induction agent. A 20 mL/kg normal saline bolus remains appropriate if dehydration is present. Heliox may be considered, although evidence is mixed and results remain inconclusive.
Medication Regimens
Albuterol may be given by nebulizer at 0.15 mg/kg per dose up to 5 mg per dose every 15–30 minutes as needed, or via MDI with spacer at 90 micrograms per puff using two puffs every 5–10 minutes to a maximum of 10 puffs. Dexamethasone can be given at 0.3 mg/kg per dose up to 16 mg. Epinephrine 1:1,000 may be administered subcutaneously at 0.01 mg/kg up to 0.35 mL per dose every 20 minutes for up to three doses. Ipratropium bromide nebulizer dosing is 250–500 micrograms per dose every six hours. Ketamine for intubation is typically 1–2 mg/kg IV as an induction agent. Levalbuterol is available in 0.63 mg and 1.25 mg vials for nebulization, typically dosed every 6–8 hours. Magnesium sulfate is dosed at 25 mg/kg IV over 20 minutes, with a maximum of about 1.2–2 g per dose. Methylprednisolone is given at 1–2 mg/kg per dose IV every six hours with a maximum of 125 mg per dose. Prednisolone is dosed 1–2 mg/kg per dose orally every 12 hours, and prednisone 1–2 mg/kg per dose orally every 6–12 hours with a maximum of 80 mg per dose. Terbutaline may be given subcutaneously as 0.01 mL/kg of 0.01% solution every 15–20 minutes up to 0.25 mL per dose, with repeated dosing per protocol. First-line therapy is albuterol plus systemic steroids with ipratropium as an adjunct, while second-line escalation includes epinephrine or terbutaline and magnesium sulfate.
Disposition And Observation
Admission decisions should be individualized using symptoms, examination, and objective measurements. Hospital admission is generally indicated for persistent wheezing, ongoing tachypnea, continued retractions or accessory muscle use, room-air saturation below 93% at sea level, peak flow below 50–70% predicted, inability to tolerate oral fluids or medications, a return ED visit within the prior 24 hours, and significant comorbidities such as congenital heart disease, bronchopulmonary dysplasia, cystic fibrosis, or neuromuscular disease, as well as concomitant pneumonia or severe viral infection. ICU-level care is indicated for severe respiratory distress, saturation below 90% or PaO2 below 60 mm Hg while receiving 40% oxygen, PaCO2 above 40 mm Hg, or significant complications such as pneumothorax or dysrhythmia. Discharge is appropriate only after a clearly good response to treatment and after observing the child for 60 minutes after the last therapy. Discharge targets include peak flow above 70% predicted for age and height, room-air saturation above 93% at sea level, normal respiratory rate, no retractions, clear lungs or only minimal wheeze, minimal or no dyspnea, and reliable follow-up and adherence. Discharge planning should include reducing exposure to smoke and allergens, continuing an intensive beta-agonist regimen for 3–5 days, and prescribing a short 3–5 day steroid course at 2 mg/kg/day for those with at least moderate symptoms. Children with moderate or severe exacerbations should have arrangements for inhaled corticosteroids over the next 1–2 months, such as fluticasone, budesonide, or beclomethasone. Follow-up should be arranged within 24–72 hours, with clear return precautions for shortness of breath that does not respond to the home regimen. Longer-term controller planning should be considered for children with recurrent attacks, persistent symptoms, or activity limitation.
Follow-Up Planning
Ongoing care is typically coordinated through the primary care clinician and often includes inhaled steroid maintenance therapy, instruction in rescue treatment, and education to support early recognition and appropriate escalation during future exacerbations.
Clinical Lessons And Safety Points
Rapid initiation of therapy with frequent reassessment is crucial to detect deterioration early. When admitting children, ensure that beta-agonist treatments continue without interruption.
Clinical Overview
Pediatric asthma is a common inflammatory airway disease affecting about 2.7 million children (<18 years) in the united states and accounts for roughly 850,000 emergency department visits annually. viral-driven airway inflammation commonly triggers bronchoconstriction, which is amplified by hyperreactivity inflammatory mediators. resulting airflow obstruction increases resistance causes gas trapping, driven mucosal edema, bronchospasm, mucus plugging. infants are particularly prone to respiratory failure because of higher peripheral resistance, reduced elastic recoil with earlier closure, an unstable rib cage, a mechanically disadvantaged diaphragm. risk influenced family history allergy early injury or vulnerability such as bronchopulmonary dysplasia, prior pneumonia, intubation, croup, reflux, passive smoke exposure; reactions foods medications other allergic conditions also support atopic predisposition. environmental exposures including pets, cigarette smoke, carpets, dust can precipitate worsen symptoms.< />pan>
Common Causes And Triggers
Exacerbations are often precipitated by infection, most commonly viral but sometimes bacterial. Environmental allergens and irritants are frequent contributors, including pollens, grasses, mold, house dust mites, and animal dander, as well as airborne chemicals such as chlorine or ammonia and food-related additives. Smoke, pollutants, gases, and aerosols may aggravate bronchospasm. Exercise, cold weather, and emotional stressors (including phobias) can provoke symptoms. Medication-related triggers include beta-blockers, aspirin, and NSAIDs.
Clinical Features
Children may present with fatigue or somnolence, diaphoresis, agitation, hypoxia or cyanosis, tachycardia, dehydration, and pulsus paradoxus. Respiratory findings include wheezing, rales, or rhonchi; acute or chronic cough; tachypnea; chest tightness; dyspnea with a prolonged expiratory phase; retractions with accessory muscle use and nasal flaring; and signs of hyperinflation. Many have a history of recurrent episodes and chronic activity restriction. Potential complications include recurrent pneumonia or bronchitis, atelectasis, pneumothorax or pneumomediastinum, and in severe cases respiratory distress, respiratory failure, or death.
History And Examination
History should focus on precipitating events and known triggers, symptom duration and progression, comorbid illness, and prior disease severity markers including previous hospitalizations, prior intubations or ICU care, and current regular or intermittent medications. Examination should include vital signs with pulse oximetry and a focused respiratory assessment. Wheeze intensity can be misleading; absent wheezing may indicate critically reduced airflow with diminished breath sounds. Look for hypoxia through skin and nail bed color changes and assess for fatigue or impending failure by noting accessory muscle use or retractions, lethargy, confusion, somnolence, or exhaustion.
Essential Evaluation
Diagnosis is clinical and relies on history and physical examination. Ventilation is assessed by observing work of breathing (retractions and accessory muscle use) and by auscultation for air exchange. Clinical response to bronchodilators should be tracked in the current episode and interpreted in the context of prior episodes. Alternative diagnoses must be considered and excluded. Initial pulse oximetry is important; an oxygen saturation below 91% at sea level correlates with more significant illness and is associated with admission risk, relapse, and a more prolonged course. Peak flow measurement can help in cooperative children, typically those older than five years; values below 50–70% of predicted suggest moderate to severe obstruction, 70–90% aligns with mild to moderate disease, and above 90% is considered normal.
Tests And Imaging
Arterial blood gas testing is not routine and is not mandatory; it can supplement oximetry for oxygenation assessment and support clinical judgment about ventilation when needed. CBC may be obtained as a nonspecific marker when infection is a concern. Theophylline levels are relevant only if a child is taking theophylline, though this therapy is not recommended. Chest radiography is considered selectively to evaluate for infiltrates, bronchial wall thickening, or hyperexpansion, and is especially considered in infants under one year to help exclude foreign body aspiration or atelectasis, in a first episode of significant wheezing to help assess chronicity and alternative diagnoses, in worsening distress or poor response to therapy, in respiratory distress or failure, and in shortness of breath without wheeze.
Differential Diagnosis
Infectious or inflammatory mimics include bronchiolitis, which can be difficult to distinguish clinically aside from age and history, and pneumonia of viral, bacterial, chemical, or hypersensitivity origin. Aspiration, deep neck or mediastinal abscesses or masses, and anaphylaxis must be considered. Structural and anatomic problems include pneumothorax and foreign body aspiration. Vascular causes include tracheal compression from vascular anomalies, pulmonary embolism, and heart failure. Congenital and chronic disorders include cystic fibrosis, tracheoesophageal fistula, bronchogenic cysts, and congenital heart disease. Other considerations include intoxication or medication effects, metabolic acidosis, neoplasm, vocal cord dysfunction, pulmonary edema (cardiogenic or noncardiogenic), and gastroesophageal reflux.
Prehospital Care
Field care emphasizes oxygen and continuous oxygen saturation monitoring, nebulized beta-agonist therapy such as albuterol, and rapid transport with clear communication to the receiving emergency team. Intubation is required for respiratory failure or profound fatigue. Intravenous fluids should be given when dehydration is evident.
Initial Stabilization In The ED
The immediate goal is to maintain oxygen saturation above 90–95% while initiating inhaled beta-agonist therapy. Intubation is indicated for respiratory failure. If dehydration is present, administer a 20 mL/kg bolus of 0.9% normal saline.
Emergency Department Management
Evaluate for impending respiratory failure, focusing on cyanosis, severe anxiety or irritability, lethargy or somnolence, fatigue, persistent tachypnea, markedly reduced air entry, and poor ventilation. Oxygen should be titrated to maintain saturations above 95% at sea level. Albuterol is the primary bronchodilator and may be given frequently or continuously in severe exacerbations. Levalbuterol may be associated with fewer side effects and may allow less frequent dosing in some children. Ipratropium bromide can be added as an adjunct, with the best benefit seen when combined with the first three beta-agonist treatments in moderate to severe presentations. Systemic steroids are recommended, using oral administration for moderate exacerbations when oral intake is possible and intravenous dosing for severe illness or inability to tolerate oral medications; a single dose of dexamethasone may be comparable to more traditional steroid courses. Subcutaneous epinephrine or terbutaline is reserved for severe or refractory cases and is used infrequently. Magnesium sulfate may help in severe asthma that persists despite standard therapy. If intubation is required, ketamine is a useful induction agent. A 20 mL/kg normal saline bolus remains appropriate if dehydration is present. Heliox may be considered, although evidence is mixed and results remain inconclusive.
Medication Regimens
Albuterol may be given by nebulizer at 0.15 mg/kg per dose up to 5 mg per dose every 15–30 minutes as needed, or via MDI with spacer at 90 micrograms per puff using two puffs every 5–10 minutes to a maximum of 10 puffs. Dexamethasone can be given at 0.3 mg/kg per dose up to 16 mg. Epinephrine 1:1,000 may be administered subcutaneously at 0.01 mg/kg up to 0.35 mL per dose every 20 minutes for up to three doses. Ipratropium bromide nebulizer dosing is 250–500 micrograms per dose every six hours. Ketamine for intubation is typically 1–2 mg/kg IV as an induction agent. Levalbuterol is available in 0.63 mg and 1.25 mg vials for nebulization, typically dosed every 6–8 hours. Magnesium sulfate is dosed at 25 mg/kg IV over 20 minutes, with a maximum of about 1.2–2 g per dose. Methylprednisolone is given at 1–2 mg/kg per dose IV every six hours with a maximum of 125 mg per dose. Prednisolone is dosed 1–2 mg/kg per dose orally every 12 hours, and prednisone 1–2 mg/kg per dose orally every 6–12 hours with a maximum of 80 mg per dose. Terbutaline may be given subcutaneously as 0.01 mL/kg of 0.01% solution every 15–20 minutes up to 0.25 mL per dose, with repeated dosing per protocol. First-line therapy is albuterol plus systemic steroids with ipratropium as an adjunct, while second-line escalation includes epinephrine or terbutaline and magnesium sulfate.
Disposition And Observation
Admission decisions should be individualized using symptoms, examination, and objective measurements. Hospital admission is generally indicated for persistent wheezing, ongoing tachypnea, continued retractions or accessory muscle use, room-air saturation below 93% at sea level, peak flow below 50–70% predicted, inability to tolerate oral fluids or medications, a return ED visit within the prior 24 hours, and significant comorbidities such as congenital heart disease, bronchopulmonary dysplasia, cystic fibrosis, or neuromuscular disease, as well as concomitant pneumonia or severe viral infection. ICU-level care is indicated for severe respiratory distress, saturation below 90% or PaO2 below 60 mm Hg while receiving 40% oxygen, PaCO2 above 40 mm Hg, or significant complications such as pneumothorax or dysrhythmia. Discharge is appropriate only after a clearly good response to treatment and after observing the child for 60 minutes after the last therapy. Discharge targets include peak flow above 70% predicted for age and height, room-air saturation above 93% at sea level, normal respiratory rate, no retractions, clear lungs or only minimal wheeze, minimal or no dyspnea, and reliable follow-up and adherence. Discharge planning should include reducing exposure to smoke and allergens, continuing an intensive beta-agonist regimen for 3–5 days, and prescribing a short 3–5 day steroid course at 2 mg/kg/day for those with at least moderate symptoms. Children with moderate or severe exacerbations should have arrangements for inhaled corticosteroids over the next 1–2 months, such as fluticasone, budesonide, or beclomethasone. Follow-up should be arranged within 24–72 hours, with clear return precautions for shortness of breath that does not respond to the home regimen. Longer-term controller planning should be considered for children with recurrent attacks, persistent symptoms, or activity limitation.
Follow-Up Planning
Ongoing care is typically coordinated through the primary care clinician and often includes inhaled steroid maintenance therapy, instruction in rescue treatment, and education to support early recognition and appropriate escalation during future exacerbations.
Clinical Lessons And Safety Points
Rapid initiation of therapy with frequent reassessment is crucial to detect deterioration early. When admitting children, ensure that beta-agonist treatments continue without interruption.
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