JAMA：中度低温与正常体温对接受VA-ECMO的心源性休克患者30天病死率的影响

Key Points

Question  Does early use of moderate hypothermia（体温过低） (33-34 °C) compared with strict（严格的） normothermia（正常体温） (36-37 °C) improve mortality in patients with cardiogenic shock receiving venoarterial extracorporeal membrane oxygenation (ECMO)?

Findings  In this randomized clinical trial that included 334 patients who had been endotracheally intubated（气管内插管） and were treated with venoarterial ECMO for less than 6 hours for refractory cardiogenic shock, mortality at 30 days was 42% for patients in the moderate hypothermia group vs 51% in the normothermia group. This difference was not statistically significant.

Meaning  For patients with cardiogenic shock receiving venoarterial ECMO, moderate hypothermia for 24 hours compared with normothermia did not significantly decrease 30-day mortality.

Abstract

Importance  The optimal approach（最佳途径） to the use of venoarterial extracorporeal membrane oxygenation (ECMO) during cardiogenic shock is uncertain.

Objective  To determine whether early use of moderate hypothermia (33-34 °C) compared with strict normothermia (36-37 °C) improves mortality in patients with cardiogenic shock receiving venoarterial ECMO.

Design, Setting, and Participants  Randomized clinical trial of patients (who were eligible if they had been endotracheally intubated and were receiving venoarterial ECMO for cardiogenic shock for <6 hours) conducted in the intensive care units at 20 French cardiac shock care centers between October 2016 and July 2019. Of 786 eligible patients, 374 were randomized. Final follow-up occurred in November 2019.

Interventions  Early moderate hypothermia (33-34 °C; n = 168) for 24 hours or strict normothermia (36-37 °C; n = 166).

Main Outcomes and Measures  The primary outcome was mortality at 30 days. There were 31 secondary outcomes including mortality at days 7, 60, and 180; a composite outcome of death, heart transplant, escalation（恶化） to left ventricular assist device implantation, or stroke at days 30, 60, and 180; and days without requiring a ventilator or kidney replacement therapy at days 30, 60, and 180. Adverse events included rates of severe bleeding, sepsis, and number of units of packed red blood cells transfused during venoarterial ECMO.

Results  Among the 374 patients who were randomized, 334 completed the trial (mean age, 58 [SD, 12] years; 24% women) and were included in the primary analysis. At 30 days, 71 patients (42%) in the moderate hypothermia group had died vs 84 patients (51%) in the normothermia group (adjusted odds ratio, 0.71 [95% CI, 0.45 to 1.13], P = .15; risk difference, −8.3% [95% CI, −16.3% to −0.3%]). For the composite outcome of death, heart transplant, escalation to left ventricular assist device implantation, or stroke at day 30, the adjusted odds ratio was 0.61 (95% CI, 0.39 to 0.96; P = .03) for the moderate hypothermia group compared with the normothermia group and the risk difference was −11.5% (95% CI, −23.2% to 0.2%). Of the 31 secondary outcomes, 30 were inconclusive（无结论）. The incidence of moderate or severe bleeding was 41% in the moderate hypothermia group vs 42% in the normothermia group. The incidence of infections was 52% in both groups. The incidence of bacteremia was 20% in the moderate hypothermia group vs 30% in the normothermia group.

Conclusions and Relevance  In this randomized clinical trial involving patients with refractory cardiogenic shock treated with venoarterial ECMO, early application of moderate hypothermia for 24 hours did not significantly increase survival compared with normothermia. However, because the 95% CI was wide and included a potentially important effect size, these findings should be considered inconclusive.