Abstract Number: VPB1119
Meeting: ISTH 2022 Congress
Background: Extracorporeal membrane oxygenation (ECMO) induces important shear stress that activates coagulation, rendering thromboprophylaxis mandatory. Unfractionated heparin (UFH) is commonly used for thromboprophylaxis and monitored with anti-Xa assay. Some of the anti-Xa’s reagents don’t contain dextran. Studies comparing anti-Xa assay with dextran (D-anti Xa) and anti-Xa assay without dextran during ECMO (ND-anti Xa) have not been published.
Aims: The study’s aim was to compare D-anti Xa and ND-anti Xa during ECMO.
Methods: Patients requiring ECMO, between May and November 2021, in the intensive care unit, were included. Anticoagulation monitoring was performed using D-anti Xa and ND-anti Xa. Patients who did not benefit simultaneously from D-anti Xa and ND-anti Xa were excluded. Kappa statistics were performed to determine consistency among D-anti-Xa and ND-anti Xa assays. The ROC curve led to a calculation of the area under the curve (AUC) for both variables.
Results: Fourteen patients were enrolled and 356 anti-Xa assays were performed. Eight patients experienced bleeding and two experienced thrombotic events during ECMO (Table 1). There was a poor agreement between the D-anti Xa and ND-Anti Xa assays, κ = 0.007 (95% CI). The ROC curve of ND-Anti Xa is represented by fig 1. The AUC of D-Anti Xa was 0.142 and 0.356 for ND-Anti Xa.
Conclusion(s): The presence of dextran in anti-Xa reagent seems to render the assay less sensitive. D-Anti Xa and ND-Anti Xa assays have poor consistency. This may be due to the release of platelet factor 4 during ECMO that binds to dextran, resulting in a false increase of heparin concentration. However, this comparison between two assays doesn’t tell us if ND-anti-XA is predictive of bleedings or thrombotic events. Further studies comparing anticoagulation monitoring assays and bleeding tendency on ECMO are needed.
To cite this abstract in AMA style:
Hammami E, Stiel L, Debliquis A, Drénou B, Harzallah i. Heparin monitoring during ECMO: Anti-Xa assay with and without dextran [abstract]. https://abstracts.isth.org/abstract/heparin-monitoring-during-ecmo-anti-xa-assay-with-and-without-dextran/. Accessed March 22, 2024.« Back to ISTH 2022 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/heparin-monitoring-during-ecmo-anti-xa-assay-with-and-without-dextran/