Hypothermia: Coming out of the cold

Accidental hypothermia is an involuntary drop in core body temperature below 35°C (normal core body temperature is 37°C). Although a significant number of deaths related to accidental hypothermia occur annually around the world, there is ambiguity in how to properly transport and treat patients affected by the condition.

"Certain treatment approaches are available only in specialized centers," the authors write, "and clarification is needed regarding the choice between transporting a patient to a specialized center and providing treatment locally. Existing recommendations do not include recent developments in rewarming methods nor do they assist with decisions regarding transportation." To fill these kinds of knowledge gaps, the paper includes sections on diagnosis, pre-hospital and hospital treatments, transport protocols and re-warming techniques, providing for the first time clear recommendation for best practices.

The paper outlines clear steps on determining the patient's condition. If the victim is stable, the paper then suggests the correct transportation procedure to a hospital where the hypothermia symptoms can be treated with minimal invasive techniques, often just an electric blanket. If the victim's condition is unstable, transportation to a specialised center with techniques of rewarming such as extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass becomes necessary.

Formerly, the abdominal or chest cavity hypothermia had to be opened to warm patients from the inside. The paper suggests that this very invasive technique yields a lower success rate (~10% survival rate) than more modern techniques of invasive rewarming such as ECMO or cardiopulmonary bypass (~50% survival).

Significant to the paper is a new medical algorithm that can help medical personnel arriving on the scene to make faster first-response decisions. Frequently working under the threat of avalanche or inclement weather, alpine doctors are confronted with the choice to transport the victim to an emergency clinic or treat the patient on site, potentially putting their own life and that of the patient in danger. Assessing the patient's prognosis based on criteria such as length of time buried under the snow and the condition of the patient's air passages is therefore crucial to deciding if resuscitation is warranted. The algorithm guides the medic through a multi-tiered decision-making process that could not only improve a victim's chance of survival, but could also help save the lives of the rescue team members.

The quartet of authors feels confident that their work will help to increase survival rates for accidental hypothermia victims in mountain regions, in which their research is focussed, but the knowledge available in the document is replicable in a variety of accidental hypothermia situations worldwide, including trauma and near-drowning.