​Kembara Xtra - Medicine - Hypothermia

​Kembara Xtra - Medicine - Hypothermia 
Accidental exposure to freezing temperatures in the environment can lead to hypothermia. The result is a core temperature of about 35°C (95°F).
Development may take several hours to days.
Patients who have been submerged in cold water may seem dead, yet sometimes they can still be revived.
Affected system(s): all bodily systems
Alternative(s): unintentional hypothermia

Epidemiology: Predominant age groups are the very young and the elderly; males outnumber females. Aspects of Geriatrics
Elderly people are more susceptible because they have reduced metabolic rates, a harder time keeping a normal body temperature, and a harder time detecting temperature fluctuations. Incidence
The CDC recorded 16,911 fatalities from hypothermia between 1999 and 2011.
Wide variations in prevalence estimates; usually a secondary problem

Pathophysiology and Etiology 

Between 36.5°C and 37.5°C, the core temperature is normally closely regulated. The most common cause of accidental hypothermia is extreme ambient cold stress. 
Other contributing elements are: 
Reduced ability to generate heat (e.g., hypopituitarism, hypothyroidism, and adrenal insufficiency) 
Increased heat loss, such as from burns or immersion (the most prevalent cause of hypothermia in emergency conditions). 
Alcohol use (shown to be responsible in up to 68% of instances)
Poor thermoregulation (stroke, CNS tumors, etc.) 

Child Safety Considerations
Children, particularly young children and infants, are more susceptible to hypothermia than adults are because young children have a bigger surface area to body mass ratio and because small infants cannot shiver to produce more heat. Children and infants have a reduced capacity to detect, avoid, or flee hypothermic exposure. Children and infants have insufficient glycogen stores to support heat generation. Additionally, the past may not support hypothermia. In children, hypothermia may not require prolonged exposure.
Trauma that wasn't caused by accident might also be a factor.

Risk factors include drinking alcohol or using drugs, bronchopneumonia, cardiovascular disease, cardiac arrest, submersion in cold water, and prolonged environmental exposure.
Burns and erythrodermas, dermal dysfunction, endocrinopathies (myxedema, severe hypoglycemia), excessive fluid loss, hepatic failure, renal failure/uremia, sepsis, malnutrition, mental illness, Alzheimer's disease, and trauma (especially head trauma).

Prevention 

 Appropriate attire, paying close attention to the head, feet, and hands
Carry survival kits with a foil blanket for use if you become trapped or hurt while participating in outdoor sports.
Beware of alcohol.
Be on the lookout for early signs and take precautions (such as drinking warm liquids and avoiding the cold) as necessary.
List any drugs (such as tranquilizers, sedatives, hypnotics, and neuroleptics) that may increase the risk of hypothermia.

Addison disease, hypothyroidism, hypopituitarism, diabetes, ketoacidosis, CNS dysfunction, congestive heart failure, pulmonary infection, sepsis, uremia are all associated conditions.

When presenting a history, it is important to consider the patient's current temperature. In the context of outdoor environmental exposures, the history is frequently obvious. In frigid indoor settings, it might not be as obvious. Patients may exhibit disorientation, vertigo, dyspnea, or changes in judgment. In situations of "indoor hypothermia," it is especially crucial to take a thorough medical history.

Caution 
Hypothermia may be overlooked in other circumstances, particularly in patients who are comatose, but a history of prolonged exposure to cold may make the diagnosis evident in those cases. If hypothermia is suspected, always take a core temperature.

clinical assessment 
Esophageal temperature measurement is the most precise, least invasive method of determining core temperature.
- Requires a secure airway
Exam results depend on the patient's temperature at the time of presentation. - Probe put into lower third of esophagus - Peripheral thermometers (tympanic membrane, temporal artery, axillary, or oral) linked with poorer accuracy.
- Mild (32-35°C)
 Sluggishness and slight confusion
Feeling shaky
 Tachypnea; tachycardia; high blood pressure
Peripheral vasoconstriction, loss of fine motor coordination, and hyperventilation
Reflexes that are overly active - Moderate (28-32°C)
The Delirium
Bradycardia, low blood pressure, and hypoventilation
 CNS depression Cyanosis Arrhythmias (prolonged PR interval, AV junctional rhythm, accelerated idioventricular rhythm, prolonged QT interval, altered T waves) 
 Muscular stiffness
Generalized swelling
Reflexes slowed to a severe degree (28 °C)
rigidity, rigid skin, apnea, bradycardia, hypotension
No pulse: asystole or ventricular fibrillation
Areflexia - Inattentive
 Pupils (fixed and dilated at 27°C; dilated alone)
ALERT
Utilize thermometers that are specially made to measure core temperatures and record low temperatures.

Child Safety Considerations
A child's body temperature lowers faster than an adult does when submerged in cold water, and altered mental status is the most crucial indicator of serious hypothermia in kids. Infants may arrive with bright red, chilly skin and very low energy.

Differential diagnosis: vascular accidents, drug overdoses, hypothyroidism, hypopituitarism, and diabetes-related complications.

Laboratory Results 

Initial examinations (lab, imaging)
Serum electrolytes; BUN/creatinine; glucose; calcium; magnesium; CBC and platelet counts; Arterial blood gases (adjusted for temperature);
Urinalysis; Coagulation Studies; Fibrinogen Level; Blood Culture; Liver Function Studies; Amylase; Cardiac Enzymes; Alcohol Level and Toxicology Screen; Bedside Ultrasound to Assess Hemodynamics; CT of the Head for Any Concern Regarding Mental Status; Cervical Spine, Chest, and Abdomen X-rays, if Appropriate; Cervical Spine, Chest, and Abdomen X-Rays 

Tests in the Future & Special Considerations
If there is underlying endocrine dysfunction, check serum cortisol and TSH levels (the hypothalamus increases the release of hormones in response to hypothermia). Diagnostic Techniques/Other Interpretations of ECG Tests
Adults with serum potassium levels >12 mmol/L are at an increased risk of dying.

Management 

Prehospital-Treatment guiding variables (While useful, core temperature alone should not be used to determine how to proceed with treatment.)  Consciousness level
 A trembling intensity
 Stability of the cardiovascular system based on heart rhythm and blood pressure - Therapy
 Primary life support
 Dry the patient off after removing wet clothing.
 Provide protection from wind chill and heat loss.
If shivering produces a considerable amount of endogenous heat, a person who is just minimally hypothermic may be able to rewarm themselves with insulation and a vapor barrier, which will be both comfortable and energy-efficient.
Add active warming for cooler, nonshivering patients because they won't rewarm on their own.

Before infusion, warm intravenous fluids.

If available, provide warm, humidified oxygen.
If the patient is far from final care, start active rewarming but do not put off transport.

Medication 
Based on the location and etiology of the underlying infection, start antibiotic treatment for sepsis or bacterial infections.
D50W at a dose of 1 mg/kg for hypoglycemia Thiamine: 100 mg if you're drunk or cachectic
Levothyroxine: 150–500 g for myxedema; 2 mg of naloxone if opioid usage is suspected.
Consider sodium bicarbonate if you have severe acidosis.
Precautions - Avoid using medications until core temperature is greater than 30 °C, including epinephrine, lidocaine, and procainamide, which can accumulate to dangerous amounts if taken repeatedly: IV medicines are recommended when the temperature exceeds 30°C. dispense slowly.
– In the event of cardiac arrest, take into account vasopressors in accordance with the conventional ACLS algorithm with concomitant rewarming.

As a result of reduced metabolism and renal elimination, usage of all medications should be done with caution. Once rewarming has taken place, depot stockpiles are mobilized. Routine use of steroids or antibiotics does not increase survival or lessen postresuscitative harm.


Admission
Rewarming is based on cardiac arrest and the degree of hypothermia.
– Consider active external rewarming if there is no cardiac arrest.
– Take vigorous internal rewarming into consideration if there is cardiac arrest.

First, warm your core.
The rate of rewarming is based on whether perfusing cardiac output is present; do not rewarm frostbitten extremities until core temperature is >34°C.
– 1-2°C/hr is suitable if a perfusing cardiac output is present.
– Use a quicker rate of >2°C/hr if not.
Monitor your heart rate, blood pressure, and core temperature.
Rectify metabolic acidosis.
Check for additional trauma and frostbite.
● Mild hypothermia, passive rewarming, and the use of heated intravenous fluids
- If you're awake and alert, provide warm liquids by mouth.
Active external rewarming and the administration of heated IV solutions in the case of moderate hypothermia.
Heated IV fluids - Heated humidified oxygen - Severe hypothermia (active internal [core] rewarming)
- Extracorporeal life support, which is the recommended treatment for cardiac arrest (5)[C] Cardiopulmonary resuscitation
oxygenation of extracorporeal membranes
- Lavage of body cavities (alternatives)
Lavage of the peritoneal cavity (40-45°C) and thoracic cavity (40-45°C)
Arteriovenous rewarming that is ongoing
Hemofiltration and hemodialysis
Cardiac arrhythmias include sinus bradycardia and atrial fibrillation, which patients can typically return to with rewarming.
– Treat with one shock if ventricular fibrillation is evident.
Consider holding off on making any more tries until the patient has been rewarmened if they don't respond.
- Temporary ventricular arrhythmias should not be treated.
– It is better to utilize an external, noninvasive pacemaker if cardiac pacing is necessary.
Patients with underlying disease, physiologic abnormalities, or core temperatures below 32°C should be admitted, ideally to the intensive care unit (ICU). When practicable, IV boluses are preferable over continuous infusions.

 If at all possible, heat IVs to between 40 and 42 °C; they shouldn't be any colder than the patient's core temperature.

Caution 
Limit your fluid intake.
Don't overheat dextrose solutions; at 60°C, dextrose starts to caramelize.
Because of the impaired lactate metabolism, avoid using lactated Ringer solution.
Take caution when transporting because the heart is agitated and prone to arrhythmias.

 Check electrolytes (especially potassium) periodically as they may change with rewarming.

 Discharge from the emergency room once normothermic, if the patient has moderate hypothermia, no problems or risk factors, and an appropriate place to go.
All others demand entry.

Patient Follow-Up Monitoring

During an acute episode, keep an eye on your heartbeat.
- Regularly check your electrolytes and glucose levels.
- Keep an eye on urination.
- Track blood gas levels.
Following an acute episode, ongoing treatment for any underlying conditions is recommended.


Diet

Only if awake and able to swallow, warm liquids

Alcohol use raises the possibility of developing hypothermia in cold weather.
Suggest that those with cardiovascular problems stay indoors during the winter instead of exercising outdoors.
 If necessary, contact a social services organization for assistance with suitable housing, heating, and/or clothing.

The prognosis is favorable because of improved therapy and greater awareness.
Mortality typically varies with age, the seriousness of the underlying cause, and comorbidities.
- A healthy patient's mortality rate is 5%.
- More than 50% of deaths are caused by comorbid diseases.
- 10% of fatalities are caused by alcohol or drug poisoning.
Aspects of Geriatrics
With age comes an increase in mortality rates. Patients older than 65 are seen to die more than half the time.


Complications include hyperkalemia and hypoglycemia as well as a reduction in core body temperature and cardiac arrhythmias. 
Rhabdomyolysis, sepsis, pneumonia (bronchopneumonia and aspiration pneumonia), and pulmonary edema 
Pancreatitis, peritonitis, gastrointestinal bleeding, ileus, acute tubular necrosis, bladder atony, intravascular thromboses/disseminated intravascular coagulation, metabolic acidosis, gangrene of the extremities, compartment syndromes, seizures, cerebral ischemia, and delirium are just a few of the conditions that can cause acute respiratory distress syndrome.