Extracorporeal Life Support Saves Lives in Severe Accidental Hypothermia
New evidence highlights how ECMO-based rewarming can restore heart function and neurological recovery in deep hypothermia cases.
Topline:
For patients with accidental hypothermia and cardiac arrest, extracorporeal life support (ECLS), primarily using ECMO, significantly improves survival and neurological outcomes compared with conventional rewarming methods.
Study Details:
Accidental hypothermia, defined as an unintentional core temperature below 35 °C (95 °F), can occur in any environment not only during exposure to extreme cold. It often affects older adults, individuals with multiple comorbidities, or those under the influence of alcohol or other psychoactive substances.
The new Insights review summarizes data from multiple international studies on the use of ECLS in severe hypothermia, particularly when cardiac arrest has occurred.
Methodology:
The review draws upon recent multicenter cohort studies, retrospective analyses, and registry data covering hundreds of patients with moderate to severe accidental hypothermia (core temperatures below 30 °C).
Prognostic scoring systems such as the HOPE, ICE, and HELP scores were evaluated to estimate survival likelihood following ECLS rewarming.
Key Findings:
High survival in cardiac arrest: In a meta-analysis of 221 patients with unwitnessed hypothermic cardiac arrest treated with ECLS, 27.1% survived, and over 83% of survivors had favorable neurological outcomes.
Better outcomes vs other causes: Compared with cardiac arrest from other causes (like heart attack or myocarditis), patients with hypothermic cardiac arrest treated with ECLS had nearly double survival rates (45.1% vs 25.6%).
Even prolonged CPR can succeed: Median resuscitation time among survivors was 105 minutes, showing the unique reversibility of hypothermic cardiac arrest.
Unreliable ETCO₂ as predictor: Low end-tidal CO₂ levels (<10 mm Hg) should not be considered an indicator of poor outcome in hypothermic patients, unlike in normothermic cardiac arrest.
ECLS improves survival in some unstable patients: In those without cardiac arrest but severe hemodynamic instability, survival was higher with ECLS (79% vs 59%), though bleeding risks were higher.
Implications for Practice:
For emergency and critical care teams, these findings reinforce that “no one is dead until warm and dead.” ECLS, particularly venoarterial ECMO, should be prioritized for patients with accidental hypothermia and cardiac arrest.
Even after prolonged downtime, meaningful neurological recovery is achievable. However, patient selection guided by scoring tools (HOPE or HELP) remains vital to balance benefit and risk, especially in those without cardiac arrest. For rural or alpine settings, rapid transport to ECMO-capable centers can be life-saving.