K. T. Carter3, R. Panchal3, J. A. Shake1, A. Panos1, R. P. Cochran1, L. Creswell1, M. E. Kutcher2, H. Copeland1 1University Of Mississippi,Cardiothoracic Surgery,Jackson, MS, USA 2University Of Mississippi,Trauma/Critical Care,Jackson, MS, USA 3University Of Mississippi,Surgery,Jackson, MS, USA
Introduction: Extracorporeal membrane oxygenation (ECMO) is an option for severe pulmonary dysfunction, but has traditionally been limited by anticoagulation requirements. Recently, the absolute requirement for anticoagulation has been challenged, potentially allowing inclusion of patients with high bleeding risk or other relative contraindications to anticoagulation. We hypothesize that among veno-venous (VV) ECMO patients, there is no difference in mortality, bleeding, or thrombotic events between a heparin-sparing and a full therapeutic anticoagulation strategy.
Methods: We conducted a single center retrospective review of all adult patients placed on VV ECMO from 10/2011 to 5/2018. Beginning in October 2014, a heparin-sparing protocol was implemented. VV ECMO was initiated without heparin or with low dose continuous intravenous (IV) heparin (activated clotting time goal 140-180) unless indications developed to start continuous therapeutic heparin. We compared ECMO patients, pre and post protocol change. The primary endpoint was survival; secondary endpoints were bleeding, thromboembolic events, and transfusion requirements.
Results: Forty adult patients were placed on VV ECMO during the study period: 17 patients (147 circuit-days) before and 23 patients (214 circuit-days) after an institutional change to a heparin-sparing protocol. Prior to the protocol change, a heparin-sparing strategy was used during 27% of the total ECMO days compared with 89% after. The post-protocol group had a lower mean body mass index (29 ± 8 vs. 38 ± 13, p=0.01), were cannulated earlier (median 1 vs. 5 day after ICU admission, p=0.03), and more commonly required inotropic support (87 vs. 41%, p=0.01), but were otherwise similar. There were no significant differences between groups in survival to decannulation (61 vs. 82%, p=0.18 ) or discharge (52 vs. 71%, p=0.33). Incidence of bleeding (41 vs. 45%, p=1.0) and thromboembolic events (18 vs. 36%, p=0.38) as well as need for transfusion (0.9 vs. 1 unit per circuit-day, p=0.87) were also similar in the pre vs. post groups. After the protocol change, 75 circuit-days (35%) were completely heparin-free. Nine patients (39%) in the post-group had entirely heparin-free courses of ECMO (total 33 circuit-days); survival and the incidence of bleeding and thrombotic complications did not differ in this heparin-free subset.
Conclusion: There is no difference in survival, bleeding, thrombotic complications, or transfusion requirements between a heparin-sparing strategy and a full therapeutic heparin strategy in the management of VV ECMO. VV ECMO can be an option in patients with traditional contraindications to anticoagulation, especially in trauma patients at high risk for bleeding.
