RESUMEN
STUDY OBJECTIVE: Severe coronavirus disease 2019 (COVID-19) increases the risk of thrombotic complications with unfractionated heparin (UFH) as a commonly used agent in managing venous thromboembolism (VTE). The optimal anticoagulation intensity and monitoring parameters in intensive care unit (ICU) COVID-19 patients remains controversial. The primary study aim was to evaluate the relationship between anti-Xa and thromboelastography (TEG) reaction (R) time in patients with severe COVID-19 receiving therapeutic UFH infusions. DESIGN: Single-center, retrospective study conducted over a 15-month period (2020-2021). SETTING: Academic medical center (Banner University Medical Center Phoenix). PATIENTS: Adult patients with severe COVID-19 administered therapeutic UFH infusions with one or more corresponding TEG, and anti-Xa assessments drawn within ≤2 hours of each other were included. The primary end point was the correlation between anti-Xa and TEG R time. Secondary aims were to describe the correlation between activated partial thromboplastin time (aPTT) and TEG R time, as well as clinical outcomes. Pearson's coefficient was used to evaluate the correlation using a kappa measure of agreement.
RESUMEN
STUDY OBJECTIVE: Thromboelastography (TEG) offers a more dynamic assessment of hemostasis over activated partial thromboplastin time (aPTT). However, the clinical utility of TEG in monitoring bivalirudin during extracorporeal membrane oxygenation (ECMO) remains unknown. The purpose of this study was to evaluate the correlation between aPTT and TEG in adult ECMO patients anticoagulated with bivalirudin. DESIGN: Multicenter, retrospective, cohort study conducted over a 2-year period. SETTING: Two academic university medical centers (Banner University Medical Center) in Phoenix and Tucson, AZ. PATIENTS: Adult patients requiring ECMO and bivalirudin therapy with ≥1 corresponding standard TEG and aPTT plasma samples drawn ≤4 h of each other were included. The primary endpoint was to determine the correlation coefficient between the standard TEG reaction (R) time and bivalirudin aPTT serum concentrations. MEASUREMENTS AND MAIN RESULTS: A total of 104 patients consisting of 848 concurrent laboratory assessments of R time and aPTT were included. A moderate correlation between TEG R time and aPTT was demonstrated in the study population (r = 0.41; p < 0.001). Overall, 502 (59.2%) concurrent assessments of TEG R time and aPTT values showed agreement on whether they were sub-, supra-, or therapeutic according to the institution's classification for bivalirudin. The 42.2% (n = 271/642) discordant TEG R times among "therapeutic" aPTT were almost equally distributed between subtherapeutic and supratherapeutic categories. CONCLUSIONS: Moderate correlation was found between TEG R time and aPTT associated with bivalirudin during ECMO in critically ill adults. Further research is warranted to address the optimal test to guide clinical decision-making for anticoagulation dosing in ECMO patients.