Extracorporeal Life Support in Severe Accidental Hypothermia: Mechanisms, Challenges and Clinical Horizons

Severe accidental hypothermia represents a unique and potentially reversible cause of cardiac arrest in which prolonged resuscitation may still result in favorable neurological recovery. Unlike normothermic cardiac arrest, hypothermic cardiac arrest (HCA) is characterized by profound metabolic suppression and temperature-mediated myocardial instability, requiring a fundamentally different therapeutic paradigm. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) provides not only circulatory support but also controlled reperfusion and rewarming, positioning it as the cornerstone of modern management. Recent international guidelines have clarified indications for extracorporeal life support (ECLS) in HCA and have contributed to improved standardization of care. Building upon these recommendations, this narrative review focuses on physiological principles underlying extracorporeal rewarming and their implications for bedside management. We examine mechanisms of ischemia-reperfusion injury, rewarming-associated hemodynamic instability and myocardial stunning, discuss dynamic risk assessment beyond statistical thresholds such as the HOPE score and summarize practical considerations regarding cannulation strategies, differential hypoxia, left ventricular unloading and neurologic evaluation. By integrating current evidence with pathophysiological insight and organizational considerations, this review proposes a clinically oriented framework to support decision-making in hypothermic cardiac arrest and to optimize meaningful neurological recovery.