澳大利亚莫纳什大学Stephen A. Bernard团队比较了低氧饱和度目标与高氧饱和度目标对院外心脏骤停复苏患者存活至出院的影响。相关论文于2022年10月26日发表在《美国医学会杂志》上。

院外心脏骤停患者恢复自主循环后，给予高比例的氧气可能会增加再灌注脑损伤。

为了确定在院外心脏骤停复苏后护理的早期阶段以较低氧饱和度为目标是否能提高出院时的存活率，研究组进行了一项多中心、平行组、随机临床试验，招募昏迷的成年人，在接受100%氧气的同时，恢复了自主循环，外周血氧饱和度（SpO₂）至少为95%。

该试验于2017年12月11日至2020年8月11日在澳大利亚维多利亚州和南澳大利亚州的2家急救医疗服务机构和15家医院进行，数据收集来自救护车和医院医疗记录（最终随访日期为2021年8月25日）。该试验纳入了原计划1416名患者中的428名。

医护人员将患者随机分组，接受氧滴定，以达到分别为90%至94%（干预；n=216）或98%至100%（标准护理；n=212）的血氧饱和度目标，直到患者到达重症监护室。主要结局是存活到出院。共收集了9个次要结局，包括缺氧发作（SpO₂<90%）和预先指定的严重不良事件，以及缺氧再休息。

由于新冠肺炎疫情，试验提前停止。在428名随机化患者中，425名患者被纳入初步分析（中位年龄为65.5岁；女性100名[23.5%]），并全部完成了试验。总体而言，干预组214名患者中有82名（38.3%）存活至出院，标准护理组211名患者中有101名（47.9%），组间差异为−9.6%，未校正比值比为0.68，组间差异显著。

在住院期间收集的9个预先指定的次要结局中，8个显示无显著差异。干预组中有67名（31.3%）在重症监护前缺氧发作，标准护理组中有34名（16.1%），差异为15.2%；OR为2.37，组间差异显著。

研究结果表明，在院外心脏骤停后实现自主循环恢复的患者中，在进入重症监护室之前，目标氧饱和为度90%至94%，与氧饱和度为98%至100%相比，并没有显著提高患者出院的存活率。虽然由于新冠肺炎大流行，该试验受到提前终止的限制，但研究结果不支持在心脏骤停复苏后在院外使用90%-94%的血氧饱和度目标。

附：英文原文

Title: Effect of Lower vs Higher Oxygen Saturation Targets on Survival to Hospital Discharge Among Patients Resuscitated After Out-of-Hospital Cardiac Arrest: The EXACT Randomized Clinical Trial

Author: Stephen A. Bernard, Janet E. Bray, Karen Smith, Michael Stephenson, Judith Finn, Hugh Grantham, Cindy Hein, Stacey Masters, Dion Stub, Gavin D. Perkins, Natasha Dodge, Catherine Martin, Sarah Hopkins, Peter Cameron, EXACT Investigators, Danny Ben-Eli, Gabriel E Blecher, Stuart J Dilley, Andis Graudins, Darsim L Haji, Peter A Jordan, Anne-Maree Kelly, Sharon L Klim, Jonathan C Knott, Michaela Mee, Jane L Lukins, Rebecca F Marson, Peter Papadopoulos, Peter D Ritchie, Julian B Stella, David McD Taylor, Stefan M Mazur, Daniel J Haustead, Margaret A Arstall, Cathrin S Parsch, Richard E Larsen, Chris R T Cotton, Joseph D Schar, Jeremy S Beer, Lucy Busija

Issue&Volume: 2022-10-26

Abstract:

Importance  The administration of a high fraction of oxygen following return of spontaneous circulation in out-of-hospital cardiac arrest may increase reperfusion brain injury.

Objective  To determine whether targeting a lower oxygen saturation in the early phase of postresuscitation care for out-of-hospital cardiac arrest improves survival at hospital discharge.

Design, Setting, and Participants  This multicenter, parallel-group, randomized clinical trial included unconscious adults with return of spontaneous circulation and a peripheral oxygen saturation (Spo2) of at least 95% while receiving 100% oxygen. The trial was conducted in 2 emergency medical services and 15 hospitals in Victoria and South Australia, Australia, between December 11, 2017, and August 11, 2020, with data collection from ambulance and hospital medical records (final follow-up date, August 25, 2021). The trial enrolled 428 of a planned 1416 patients.

Interventions  Patients were randomized by paramedics to receive oxygen titration to achieve an oxygen saturation of either 90% to 94% (intervention; n = 216) or 98% to 100% (standard care; n = 212) until arrival in the intensive care unit.

Main Outcomes and Measures  The primary outcome was survival to hospital discharge. There were 9 secondary outcomes collected, including hypoxic episodes (Spo2 <90%) and prespecified serious adverse events, which included hypoxia with rearrest.

Results  The trial was stopped early due to the COVID-19 pandemic. Of the 428 patients who were randomized, 425 were included in the primary analysis (median age, 65.5 years; 100 [23.5%] women) and all completed the trial. Overall, 82 of 214 patients (38.3%) in the intervention group survived to hospital discharge compared with 101 of 211 (47.9%) in the standard care group (difference, 9.6% [95% CI, 18.9% to 0.2%]; unadjusted odds ratio, 0.68 [95% CI, 0.46-1.00]; P=.05). Of the 9 prespecified secondary outcomes collected during hospital stay, 8 showed no significant difference. A hypoxic episode prior to intensive care was observed in 31.3% (n=67) of participants in the intervention group and 16.1% (n=34) in the standard care group (difference, 15.2% [95% CI, 7.2%-23.1%]; OR, 2.37 [95% CI, 1.49-3.79]; P<.001).

Conclusions and Relevance  Among patients achieving return of spontaneous circulation after out-of-hospital cardiac arrest, targeting an oxygen saturation of 90% to 94%, compared with 98% to 100%, until admission to the intensive care unit did not significantly improve survival to hospital discharge. Although the trial is limited by early termination due to the COVID-19 pandemic, the findings do not support use of an oxygen saturation target of 90% to 94% in the out-of-hospital setting after resuscitation from cardiac arrest.

DOI: 10.1001/jama.2022.17701

Source: https://jamanetwork.com/journals/jama/fullarticle/2798013