Original Articles

The Heparin-Antithrombin Product: A Novel Value for Pediatric Extracorporeal Anticoagulation

^* Indiana University School of Medicine and
^† Division of Pediatric Critical Care Medicine, Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana

Address correspondence to: Colin M. Rogerson, MD, Assistant Professor of Pediatrics, Division of Pediatric Critical Care Medicine, Department of Pediatrics, Riley Hospital for Children at Indiana University Health, 705 Riley Hospital Drive, Indianapolis, IN 46202. E-mail: crogerso@iupui.edu

Received: 11 November 2021
Accepted: 14 May 2022

Abstract

Hematologic complications are a source of morbidity and mortality for patients receiving extracorporeal membrane oxygenation (ECMO) support. There is no consensus strategy for monitoring anticoagulation for children supported with ECMO. This study evaluated a novel measurement of anticoagulation for children on ECMO. This was a single-center observational study of children supported with ECMO from 2015 to 2020. Each patient’s current unfractionated heparin dose was multiplied by the current antithrombin III (AT) level to obtain a novel anticoagulation value, the heparin-antithrombin product (HAP). This value was compared with the heparin dose, AT, and activated clotting time (ACT) to predict anti-Xa value using linear correlation and decision tree methods. Data were obtained from 128 patients supported with ECMO. The HAP value was more highly correlated with anti-Xa level than heparin dose, AT level, and ACT. This correlation was highest in the neonatal population (r = .7). The variable importance metrics from the regression tree and random forest models both identified the HAP value as the most influential predictor variable for anti-Xa value. The HAP value is more highly correlated with the anti-Xa level than heparin dose, AT level, or ACT. Further research is needed to evaluate the effectiveness of the HAP value as a measurement of anticoagulation for children on ECMO.