Conventional versus restricted anti-Xa-guided heparin protocol in adult patients undergoing extracorporeal membrane oxygenation.

Objective: The optimal intensity of anticoagulation for adult patients supported with extracorporeal membrane oxygenation (ECMO) remains uncertain. The objective of this study was to evaluate the effectiveness and safety of two anticoagulation protocols using conventional (0.3-0.7 IU/ml) versus restricted (0.2-0.5 IU/ml) anti-factor Xa (anti-Xa) targets for the management of unfractionated heparin (UFH) in adult ECMO patients.

Methods: This retrospective before-after cohort study compared two groups of ECMO patients who received UFH for at least 24-h from March 2016 to May 2019. The primary outcome was the composite rate of major bleeding or thrombotic events per ECMO day. Secondary outcomes included the mean amount of blood products transfused per ECMO day, the proportion of patients who were within the target anti-Xa at 24-h, the time to achieve target anti-Xa, and the number of heparin infusion adjustments to reach target anti-Xa.

Results: Forty-one patients were included in this analysis (conventional, n = 25; restricted, n = 16). There was no difference in the composite rate of major bleeding or thrombotic events per ECMO day (p = .090). The restricted group had lower rates of packed red blood cells (pRBC) transfusion per ECMO day (mean 1 ± 1 vs 3 ± 2 units, p = .003) and required fewer heparin infusion adjustments to reach the target (p = .007). There was no difference between the groups in the number of patients who achieved target anti-Xa at 24-h (p = .940).

Conclusion: In adult ECMO patients, anticoagulation with a restricted anti-Xa target was associated with lower pRBC transfusions and did not provoke an excess of thrombotic events.