The First Series Of Hypothermic Out-of-hospital Cardiac Arrests In A Temperate Urban Area Resuscitated With Prehospital Or Inhospital Extracorporeal Cardiopulmonary Resuscitation: A Fifteen-year Observationnal Study

Introduction: Accidental hypothermia designates an unpredicted drop in body temperature below 35°C. The risk of ventricular fibrillation is major below 28°C and cardiac arrest is almost certain below 24°C. In such cases, conventional cardiopulmonary resuscitation is often inefficient. Hypothesis: Hypothermic out-of-hospital cardiac arrest (OHCA) occurs even in temperate urban areas and extracorporeal cardiopulmonary resuscitation (ECPR) has shown good outcomes with this indication. Methods: We conducted a retrospective observational study of patients admitted to a university hospital in Paris, France. We reviewed patients consecutively admitted between January 1, 2008 and April 31, 2022 and treated with prehospital or inhospital ECPR following refractory hypothermic OHCA. The primary outcome was survival at 28 days with good neurological outcomes, defined as Cerebral Performance Category (CPC) 1 or 2. We compared patients according to their cold air or cold water exposure. Results: A total of 38 patients were analysed. Patient characteristics and outcomes are detailed in Table 1. A total of 15 patients (40%) survived at 28 days, 13 (34%) of whom with good neurological outcomes despite a median low-flow of 85 min. No patient survived with good neurological outcomes in the cold-water group. Conclusion: Survival rates with favourable neurological outcomes at 28 days stood at 34% of all patients with hypothermic OHCA who were resuscitated with ECPR. Prehospital ECPR tended to show better survival results (39% vs 30%) but further data are needed to confirm this as the difference was not statistically significant. We found no survivors in the cold-water group raising the question of ECPR indication for these patients in temperate urban areas. In any case, temperature measurement should be systematic in OHCA and there should be predefined care pathways including ECPR for hypothermic OHCA patients even in urban settings with a temperate climate.