Original Articles

Anticoagulant Use During Extracorporeal Membrane Oxygenation Using Heparin and Direct Thrombin Inhibitors in COVID-19 and ARDS Patients

^* SpecialtyCare, Brentwood, Tennessee;
^† St. Elizabeth Medical Center, Appleton, Wisconsin; and
^‡ University of Florida, Gainesville, Florida

Address correspondence to: Alfred H. Stammers, MSA, CCP (Emeritus), Vice President, Clinical Quality and Outcomes Research, SpecialtyCare, 3 Maryland Farms, Suite 200, Brentwood, TN 37027-5005. E-mail: al.stammers@specialtycare.net

Received: 12 April 2022
Accepted: 17 August 2022

Abstract

Coagulopathies develop in patients supported with the use of extracorporeal membrane oxygenation (ECMO) and can be hemorrhagic and/or thrombophilic in spite of the use of systemic anticoagulation. The purpose this study was to examine the use of heparin and direct thrombin inhibitors (DTI) in COVID-19 patients with acute respiratory distress syndrome (ARDS) on ECMO, with a subset analysis by disease state. Following IRB approval, 570 consecutive records were reviewed of adult patients on venovenous ECMO between May 2020 and December 2021. Patients were grouped by anticoagulant use: Heparin Only (n = 373), DTI Only (bivalirudin or argatroban, n = 90), or DTI after Heparin (n = 107). The effect of anticoagulant grouping was assessed using Bayesian mixed-effects logistic regression adjusting for age, body mass index (BMI), gender, days of mechanical ventilation prior to ECMO, indication for ECMO support, hepatic and renal failure, hours on ECMO, hours off anticoagulation, coagulation monitoring target, and hospital. The primary endpoint was circuit failure requiring change-out with secondary endpoints of organ failure and mortality. Regression-adjusted probability of circuit change-outs were as follows: DTI after Heparin patients—32.7%, 95% Credible Interval [16.1–51.9%]; DTI Only patients—23.3% [7.5–40.8%]; and Heparin Only patients—19.8% [8.1–31.3%]. The posterior probability of difference between groups was strongest for DTI after Heparin vs. Heparin Only (97.0%), moderate for DTI after Heparin vs. DTI Only (88.2%), and weak for DTI Only vs. Heparin only (66.6%). The occurrence of both hepatic and renal failure for DTI Only and DTI after Heparin patients was higher than that of Heparin Only patients. Unadjusted mortality was highest for DTI after Heparin (64.5%) followed by DTI Only (56.7%), and Heparin Only (50.1%, p = 0.027). DTI after Heparin was associated with an increased likelihood of circuit change-out. Unadjusted hepatic failure, renal failure, and mortality were more frequent among DTI patients than Heparin Only patients.