What are the management strategies for hypothermia?

Hypothermia Management

Temperature Measurement and Classification

Accurate core temperature measurement is essential—always use low-reading thermometers and base treatment decisions on core temperature rather than clinical presentation alone, as patients can appear deceptively stable despite life-threatening hypothermia. 1

• Oral or esophageal probes are preferred for monitoring when pulmonary artery catheters are not warranted 2
• Tympanic infrared probes serve as acceptable alternatives when oral measurement is not feasible 2
• Avoid axillary measurements as they consistently read 1.5-1.9°C below actual core temperature 2
• Classify hypothermia severity: mild (32-35°C), moderate (28-32°C), severe (<28°C), and profound (<24°C) 3

Immediate Initial Actions (All Severity Levels)

• Remove all wet clothing immediately to prevent further heat loss 4, 5
• Move patient to warm environment and shield from wind 3
• Cover with at least two warm blankets and insulate from cold ground surfaces 4
• Cover head and neck to minimize heat loss 4
• Handle patient gently throughout to avoid triggering ventricular fibrillation 4

Treatment Algorithm Based on Core Temperature

Mild Hypothermia (32-35°C)

• Allow passive rewarming with blankets and increased environmental temperature 3
• Provide high-calorie foods or warm drinks if patient is alert 3
• Monitor core temperature every 15 minutes 3
• Watch for signs of deterioration requiring escalation 3

Moderate Hypothermia (28-32°C)

• Continue all Level 1 interventions from mild hypothermia 3
• Apply forced-air warming blankets (e.g., Bair Hugger) for active external rewarming 4, 5
• Add heating pads and radiant heaters as available 5
• Administer warmed intravenous fluids (lactated Ringer's or normal saline) 4
• Provide humidified, warmed oxygen 4
• Monitor core temperature every 5-15 minutes 3

Severe Hypothermia (<28°C)

For severe hypothermia, implement aggressive active core rewarming immediately while continuing all external warming measures, as mortality risk is substantial without rapid intervention. 4, 5

• Continue all Level 1 and Level 2 interventions 5
• Activate emergency response system for advanced support 3
• Administer warmed IV fluids rapidly (1500-3000 mL of 4°C saline or Ringer's lactate can be used for rapid induction) 6
• Consider peritoneal lavage with warmed fluids for active core rewarming 5
• For patients with end-stage renal failure or when available, hemodialysis achieves rapid rewarming at 1.9°C/hour 7
• Monitor core temperature every 5 minutes continuously 4
• Handle with extreme gentleness to prevent arrhythmia triggering 4

Rewarming Targets and Endpoints

• Target minimum core temperature of 36°C before considering patient stable or transferring between units 3, 5
• Cease active rewarming at 37°C—higher temperatures are associated with poor outcomes and increased mortality 3, 5
• Shivering can increase rewarming rate up to 3.6°C/hour 5

Critical Monitoring During Rewarming

• Continuously monitor for cardiac arrhythmias, particularly as temperature rises 3, 4
• Watch for coagulopathy development, especially below 34°C where each 1°C decrease causes 10% reduction in coagulation factor function 5
• Monitor for rewarming shock and hypotension 3
• Assess for burns from improper use of active external rewarming devices 3
• Obtain ECG after resolution of shivering to evaluate for arrhythmias 1

Laboratory and Diagnostic Evaluation

• Obtain cortisol levels as hypothermia can unmask endocrine dysfunction 3
• Monitor for rhabdomyolysis in severe cases 1
• Assess for metabolic derangements and electrolyte abnormalities 8

Critical Pitfalls to Avoid

• Never rely on clinical presentation alone—patients with severe hypothermia (25°C) can appear alert and communicative, masking true disease severity 1
• Hypothermia is frequently overlooked during initial resuscitation—prevention is easier than treatment once significant heat loss occurs 5
• Avoid rapid active warming in post-cardiac arrest patients where therapeutic hypothermia (32-36°C) may be indicated 5
• Do not use pulmonary artery catheters routinely in trauma as they are cumbersome and associated with complications including arrhythmias and perforation 2

Prehospital Considerations

• Implement Level 1 strategies immediately in the field, even without core temperature measurement 5
• Early organized prehospital hypothermia protocols reduce incidence from 19% to 3% 5