Comparison of anticoagulation strategies for veno-venous ECMO support in acute respiratory failure

Background: There is wide variability in anticoagulation strategies for veno-venous (VV-) extracorporeal membrane oxygenation (ECMO) for acute respiratory failure. Methods: We conducted a retrospective comparison of unfractionated heparin (UFH)-based anticoagulation strategies between two ECMO centers: 1 - high dose (HD) group: Two hourly ACT-based therapeutic anticoagulation with a target of 140-180s. 2 - low dose (LD) group: Thrice daily PTT-based prophylactic anticoagulation with UFH with a pro-thrombin time (PTT) target of 35-40s. The primary outcome was number of oxygenator changes per patient. Secondary outcomes were coagulation studies, and severe bleeding and thromboembolic events. Results: 215 patients were included (HD group 116, LD group 99). Disease severity in both groups was comparable (SAPS score 47.4±13.7 vs 48.0±12.9, p=0.710). Consistent with the chosen strategy, the mean PTT was longer in the HD group (51±17s vs 39±8s, p Conclusion: A LD heparinization strategy in VV-ECMO was associated with more oxygenator changes and more thromboembolic events compared to HD heparinization. No differences were seen regarding severe bleeding events and in-hospital mortality. Overall, the data favor the HD strategy, at least in patients not at high risk of bleeding.