Use of Thromboelastography to Predict Thrombotic Complications in Pediatric and Neonatal Extracorporeal Membranous Oxygenation

Abstract

The objectives of this study were to investigate the correlation between thromboelastography (TEG) and conventional measures of anticoagulation, and to determine optimum values for citrated kaolin TEG R time (TEG RCK) and anti-Xa activity that would minimize both bleeding and thrombotic complications in pediatric and neonatal patients requiring extracorporeal membranous oxygenation (ECMO). A retrospective chart review of patients requiring veno-venous (VV) and venoarterial (VA) ECMO was performed. Combined medical and cardiac ICU within a single-center, tertiary care, freestanding, children's hospital. Non-pregnant patients <18 years and >2 kilograms requiring VV or VA ECMO from July 2013 through July 2015. Anti-Xa (OR = 0.62, 95% CI 0.53-0.72, p < .001) and TEG RCK (OR = 1.19, 95% CI 1.07-1.34, p = .003) were the only independent predictors for a significant thrombotic event. Receiver operating characteristic curves and traditional epidemiological data (sensitivity, specificity, PPV, NPV) were used to determine optimal target Anti-Xa and TEG RCK values. No independent predictors for significant bleeding events were identified in this cohort. A anti-Xa activity of .25 IU/mL (sensitivity = 81%, specificity = 67%, PPV = 81%, NPV = 58%) and TEG RCK time of 17.85 minutes (sensitivity = 84%, specificity = 68%, PPV = 82%, NPV = 59%) were established as the optimal thresholds for preventing thrombotic events. Anti-Xa and TEG RCK were independent predictors of thrombosis in this cohort of pediatric and neonatal ECMO patients. Targeting an anti-Xa activity greater than .25 IU/mL and a TEG RCK greater than 17.85 minutes may minimize the risk of thrombosis in pediatric and neonatal ECMO patients. Future investigation should evaluate targets for anti-Xa and TEG RCK, which additionally minimize the risk of significant bleeding in this patient population.

Keywords: extracorporeal membrane oxygenation; heparin management; neonatal; pediatrics; thromboelastography; thrombosis.

Figure 1.

Anticoagulation test response table.

Figure 2.

ROC curves predicting a thrombotic event.