RATIONALE Definitive guidelines for anticoagulation management during veno-venous extracorporeal membrane oxygenation (VV ECMO) are lacking, while bleeding complications continue to pose major challenges. OBJECTIVES To describe anticoagulation modalities and bleeding events in adults receiving VV ECMO. METHODS International prospective observational study in 41 centers, from December 2018 to February 2021. Anticoagulation was recorded daily in terms of type, dosage, and monitoring strategy. Bleeding events were reported according to site, severity, and impact on mortality. MEASUREMENTS AND MAIN RESULTS The study cohort included 652 patients, and 8471 days on ECMO were analyzed. Unfractionated heparin (UFH) was the initial anticoagulant in 77% of patients, and the most used anticoagulant during the ECMO course (6221 days, 73%). Activated partial thromboplastin time (aPTT) was the most common test for monitoring coagulation (86% of days): the median value was 52 seconds (39-61), but dropped by 5.3 seconds after the first bleeding event (95% CI -7.4 to -3.2, p< 0.01). Bleeding occurred on 1202 days (16.5 %). Overall, 342 patients (52.5 %) experienced at least one bleeding event (one episode every 215 hours on ECMO), of which 10 (1.6%) were fatal. In a multiple penalized Cox proportional hazard model, higher aPTT was a potentially modifiable risk factor for the first episode of bleeding (for 20 seconds increase, hazard ratio 1.07). CONCLUSIONS Anticoagulation during VV ECMO was a dynamic process, with frequent stopping in cases of bleeding, and restart according to the clinical picture. Future studies might explore lower aPTT targets to reduce the risk of bleeding.

中文翻译：

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静脉-静脉体外膜氧合过程中的抗凝和出血：PROTECMO 研究的见解。

基本原理 静脉-静脉体外膜氧合 (VV ECMO) 期间的抗凝管理尚缺乏明确的指南，而出血并发症仍然构成重大挑战。目的 描述接受 VV ECMO 的成人的抗凝方式和出血事件。方法 2018年12月至2021年2月在41个中心进行的国际前瞻性观察研究。每天记录抗凝治疗的类型、剂量和监测策略。根据出血部位、严重程度和对死亡率的影响来报告出血事件。测量和主要结果 研究队列包括 652 名患者，分析了 8471 天的 ECMO。普通肝素 (UFH) 是 77% 患者的初始抗凝剂，也是 ECMO 疗程中最常用的抗凝剂（6221 天​​，73%）。活化部分凝血活酶时间 (aPTT) 是监测凝血的最常见测试（86% 的天数）：中值为 52 秒 (39-61)，但在第一次出血事件后下降了 5.3 秒 (95% CI -7.4至-3.2，p<0.01）。1202 天发生出血（16.5%）。总体而言，342 名患者 (52.5%) 经历了至少一次出血事件（ECMO 每 215 小时发生一次），其中 10 名患者 (1.6%) 死亡。在多重惩罚 Cox 比例风险模型中，较高的 aPTT 是首次出血的潜在可改变风险因素（增加 20 秒，风险比为 1.07）。结论 VV ECMO 期间的抗凝是一个动态过程，在出血情况下经常停止，并根据临床情况重新启动。未来的研究可能会探索降低 aPTT 目标以降低出血风险。