Extracorporeal membrane oxygenation improves outcomes of accidental hypothermia without vital signs: A nationwide observational study

Aim: Patients with accidental hypothermia without vital signs increasingly receive venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, there is limited knowledge regarding the efficacy of this advanced rewarming method. We aimed to determine whether VA-ECMO improved outcomes in patients with accidental hypothermia without vital signs, using a large nationwide inpatient database in Japan.

Methods: Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2017, we identified patients diagnosed with accidental hypothermia who received closed-chest cardiac massage in-hospital on the day of admission. Patients who received VA-ECMO on the day of admission were allocated to the VA-ECMO group, and those who received cardiopulmonary resuscitation (CPR) only were allocated to the conventional CPR group. The primary outcome was in-hospital mortality, and the secondary outcome was a Japan Coma Scale status of "alert consciousness" at discharge. Propensity score-matching analyses were performed to compare the outcomes.

Results: We identified 1661 eligible patients during the 81-month study period, and 318 (19%) received VA-ECMO on the day of admission. Crude in-hospital mortality was 65% in the VA-ECMO group and 84% in the conventional CPR group. Propensity score-matching analyses demonstrated significantly lower in-hospital mortality (risk difference: -13%; 95% confidence interval: -21% to -5.1%) and a higher proportion of "alert consciousness" at discharge (risk difference: 8.3%; 95% confidence interval: 1.9%-15%) in the VA-ECMO group compared with the conventional CPR group.

Conclusion: VA-ECMO was associated with higher survival and favourable neurological outcomes compared with conventional CPR alone in patients with accidental hypothermia without vital signs.