From the Guidelines
Treatment for hypothermia should focus on warming the body safely while preventing further heat loss, with the approach varying based on the severity of hypothermia, as outlined in the 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. For mild hypothermia (body temperature 32-35°C), passive rewarming techniques are generally adequate and include removing wet clothing, covering with warm blankets, and moving to a warm environment.
- Active external rewarming methods, such as applying heating pads or warm water bottles to the neck, chest, and groin areas, are more appropriate for moderate hypothermia (28-32°C).
- For severe hypothermia (below 28°C), more aggressive interventions are necessary, including warm IV fluids, warm humidified oxygen, and in critical cases, techniques like peritoneal lavage with warm fluids, pleural lavage, or extracorporeal membrane oxygenation (ECMO) 1. It's crucial to handle hypothermic patients gently as rough movement can trigger cardiac arrhythmias.
- Rewarming should be done gradually, typically at a rate of 0.5-2°C per hour depending on severity, to prevent complications like "rewarming shock" where peripheral vasodilation can cause a drop in blood pressure.
- CPR should be continued in severely hypothermic patients who appear lifeless until they are warmed to at least 32°C, following the principle that "no one is dead until they're warm and dead" 1. The most recent and highest quality study, from 2020, provides the basis for these recommendations, emphasizing the importance of prompt and appropriate treatment to improve outcomes in hypothermic patients 1.
From the Research
Treatment Options for Hypothermia
The treatment of hypothermia depends on the degree of hypothermia present, ranging from noninvasive, passive external warming techniques to active external rewarming and active core rewarming 2. The following are some treatment options for hypothermia:
- Passive external warming techniques, such as removal of cold, wet clothing and movement to a warm environment 2, 3
- Active external rewarming techniques, such as insulation with warm blankets and forced air patient warming systems 2, 3, 4
- Active core rewarming techniques, such as warmed intravenous fluid infusions, heated humidified oxygen, body cavity lavage, and extracorporeal blood warming 2, 5
- Endovascular catheters as a rewarming method for accidental hypothermia 6
- Direct blood warming or infusion of warm intravenous fluids, which are considered the most effective rewarming techniques 5
Considerations for Treatment
When treating hypothermia, it is essential to consider the patient's core body temperature, as clinical presentation may not always accurately reflect the severity of the condition 4. The treatment of severe hypothermia is more complex and requires careful consideration of the patient's clinical resources and the potential need for invasive and aggressive rewarming techniques 2, 6.
Rewarming Methods
Various rewarming methods are available, including:
- Passive rewarming, which relies on endogenous heat-producing mechanisms and is suitable for mild hypothermia cases 3
- Active rewarming, which includes methods such as warm air inhalation, forced air methods, and endovascular catheters 3, 6
- A combination of passive and active rewarming methods, which may be necessary for moderate or severe hypothermia cases 3, 4