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.

Anticoagulation and Transfusion Management During Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Survey of Medical Directors in the United States*

“…Recently, a multicenter randomized controlled trial demonstrated anticoagulation with a thromboelastography-based protocol is both safe and feasible for adults requiring venovenous ECMO (47). Therapeutic ranges for the neonatal and pediatric population are not well established, and current data are limited to small retrospective studies (48, 49). Therefore, thromboelastography currently provides useful information as an ancillary study.…”

2021 ELSO Adult and Pediatric Anticoagulation Guidelines

“…38,39 The literature regarding use of VHAs in ECMO is increasing and small RCTs and retrospective case series have shown differing results regarding use of VHAs as predictors of clotting and bleeding. 40–43…”

Analysis of Viscoelastic Testing in Pediatric Patients Using the Pediatric Extracorporeal Membrane Oxygenation Outcomes Registry

“…14,18,21–23 In a 2018 study by Panigada et al , 24 the authors demonstrated that the use of a TEG-based anticoagulation protocol with a target R time of 16–24 minutes compared with a standard of care aPTT protocol in adult patients on ECMO did not result in a higher incidence of hemorrhagic or thrombotic complications. In a study by Henderson et al , 25 an R time of 17 minutes was associated with fewer thrombotic complications in a pediatric ECMO population. Although the TEG R time targets referenced above have not been validated in multicenter prospective studies, it suggests a potentially safe target for heparin titration during ECMO.…”