Colleen Menegaz, MD
UT Southwestern Children's Medical Center
Dallas, Texas
Disclosure information not submitted.
Lakshmi Raman, MD
Associate Professor of Pediatrics
University of Texas Southwestern
Dallas, Texas, United States
Disclosure information not submitted.
Christopher Jenks, MD, MS
Assistant Professor of Pediatrics
Oklahoma University Children's Hospital, United States
Disclosure information not submitted.
Ali McMichael, MD
Assistant Professor of Pediatrics
University of Texas Southwestern Medical Center, United States
Disclosure information not submitted.
Title: Thromboelastography Does Not Predict Bleeding or Clotting in Pediatric ECMO
Introduction: Bleeding and thrombosis cause significant morbidity and mortality in pediatric patients on extracorporeal membrane oxygenation (ECMO). Anticoagulation is required to prevent thrombotic complications and is titrated using labs such as anti-Xa, PTT, and ACT. Thromboelastography (TEG) is often used in addition as it describes the dynamic clotting process and provides a comprehensive picture of in vivo hemostasis. We hypothesize that TEG is predictive of hemostatic complications in pediatric ECMO.
Methods: A single center, retrospective analysis of VV and VA ECMO patients aged birth to 18 years anticoagulated with UFH between 2014 and 2018 was performed. Primary outcomes included cannula or surgical site bleeding, gastrointestinal or respiratory tract bleeding, and ECMO circuit clot burden or circuit change. Lab values within 24 hours of an event were compared to median lab values in patients without an event using odds ratio and confidence intervals. Spearman correlation coefficient was used to compare TEG values with anti-Xa level, PT/INR, PTT and fibrinogen drawn within 2 hours of TEG sample.
Results: A total of 201 patients with 212 ECMO runs were included. Standard coagulation labs and TEG values inconsistently predicted events. Increased PTT was associated with bleeding from endotracheal and chest tubes [91 (60-136) vs 76 (52-93), p=0.008] and increased PT [20 (16-24) vs 16 (15-17), p=0.01] and INR [1.55 (1.25-2.1) vs 1.2 (1.1-1.3), p=0.003] were associated with surgical site bleeding. D-dimer was higher in patients who required circuit change versus those who did not [12 (5.9-20) vs 4 (1.8-9.2), p=0.0001). TEG values indicative of clot strength, including TEG-G, α-angle, and TEG maximum amplitude (TEG-MA) were elevated in patients with cannula site bleeding, which is of unclear clinical significance. TEG reaction time (TEG-R) had strong positive correlation with PTT (r=0.79, p< 0.0001) and moderate positive correlation with anti-Xa level (r=0.55, p=0.0001). TEG-MA had strong positive correlation with fibrinogen (r=0.82, p< 0.0001).
Conclusions: TEG-R correlated with PTT and anti-Xa levels. Elevated standard coagulation labs were predictive of bleeding; however, TEG was not predictive of bleeding or clotting. More data is needed to demonstrate clinical application of TEG in ECMO patients.