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

J Extra Corpor Technol. 2022 Jun;54(2):115-122. doi: 10.1182/ject-115-122.


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.

Keywords: anticoagulation; critical care medicine.; extracorporeal membrane oxygenation; pediatrics.

Publication types

  • Observational Study

MeSH terms

  • Anticoagulants / therapeutic use
  • Antithrombin III*
  • Antithrombins
  • Child
  • Extracorporeal Membrane Oxygenation* / methods
  • Heparin* / therapeutic use
  • Humans
  • Infant, Newborn
  • Retrospective Studies


  • Anticoagulants
  • Antithrombins
  • Antithrombin III
  • Heparin