What is the treatment approach for hypothermia?

Treatment of Hypothermia

Treat hypothermia using a tiered, severity-based approach: passive rewarming for mild cases (32-35°C), active external rewarming for moderate cases (28-32°C), and active internal rewarming for severe cases (<28°C), with immediate removal of wet clothing and prevention of further heat loss as the universal first step. 1, 2

Immediate Universal Interventions (All Severity Levels)

• Remove all wet clothing immediately to prevent ongoing heat loss 3, 2
• Move the patient to a warm environment and shield from wind 1
• Cover with at least two warm blankets and insulate from cold ground surfaces 3
• Cover the head and neck, as these are major sites of heat loss 1, 3
• Handle the patient gently throughout to avoid triggering ventricular fibrillation, especially in severe cases 3

Severity-Based Treatment Algorithm

Mild Hypothermia (32-35°C): Level 1 Interventions

• Allow passive rewarming with blankets and increased environmental temperature 1, 2
• Provide high-calorie foods or warm drinks if the patient is alert and able to swallow 1
• Monitor for signs of deterioration, as passive rewarming alone produces a natural rate of 1.2°C/hour, increasing to 3.6°C/hour with shivering 4, 2
• Note that passive rewarming may actually cause temperature decrease during transport, so active methods are preferred even in mild cases 4

Moderate Hypothermia (28-32°C): Level 1 + Level 2 Interventions

• Continue all Level 1 measures 1, 2
• Apply forced warm air blankets (e.g., Bair Hugger) as the primary active external rewarming method 4, 3
• Use heating pads, radiant heaters, or chemical heat blankets as additional external warming 4, 1, 2
• Administer warmed intravenous fluids (all IV fluids must be reliably warmed before infusion) 4, 3, 5
• Provide humidified, warmed oxygen to support respiratory function 1, 3
• Monitor core temperature every 5-15 minutes depending on clinical status 1, 3

Severe Hypothermia (<28°C): Level 1 + Level 2 + Level 3 Interventions

• Continue all measures for moderate hypothermia 1, 3
• Activate the emergency response system immediately 1
• Implement active core rewarming methods including peritoneal lavage with warmed fluids 2
• Consider extracorporeal modalities such as dialysis, cardiopulmonary bypass, or extracorporeal life support for profound hypothermia (<24°C) or cardiac arrest 4, 6
• Monitor core temperature every 5 minutes to assess rewarming progress 3
• Note that external rewarming can still be effective even in severe hypothermia, with studies showing successful warming of patients below 30°C using forced-air warmers 4, 2

Critical Rewarming Targets and Endpoints

• Target a minimum core temperature of 36°C before considering the patient stable or transferring between units 1, 3, 2
• Cease rewarming at 37°C, as higher temperatures are associated with poor outcomes 1, 3, 2
• Active internal rewarming restores temperature faster than surface methods and normalizes cardiac output more rapidly 4

Monitoring for Complications During Rewarming

• Continuously monitor for cardiac arrhythmias, which are the most dangerous complication during rewarming 1, 3
• Watch for rewarming shock (hypotension from peripheral vasodilation) 1
• Assess for coagulopathy, which completely resolves with aggressive warming in trauma patients 4, 1
• Check for burns from improper use of active external rewarming devices 1
• Obtain laboratory studies including cortisol levels for diagnostic evaluation 1

Prehospital Management Considerations

• Implement Level 1 strategies immediately in the field, even without core temperature measurement 2
• Early organized prehospital hypothermia protocols reduce incidence from 19% to 3% 4, 2
• For transport times exceeding 45 minutes, actively but gently warm patients as soon as possible 7
• The amount of warming received during the prehospital phase is the most important factor in preventing hypothermia-related complications 4

Common Pitfalls to Avoid

• Hypothermia is often overlooked during initial resuscitation—make temperature assessment a priority 2
• Emphasis must be on prevention first and treatment second, as it becomes increasingly difficult to rewarm once significant heat is lost 4, 2
• Do not rely solely on passive rewarming for moderate or severe cases, as it is ineffective without adequate endogenous heat production 4
• Take extra time to check for life signs before initiating CPR, as hypothermia can mimic cardiac arrest 7
• Avoid overventilation during resuscitation and maintain regular normothermic chest compression rates 7