Evaluation of heparin assay for coagulation management in newborns undergoing ECMO

Am J Clin Pathol. 2010 Dec;134(6):950-4. doi: 10.1309/AJCPGVD62LKKVDLH.


The objective was to identify the usefulness of heparin level by anti-factor Xa (anti-Xa) assay vs activated partial thromboplastin time (PTT) or activated clotting time (ACT) in neonates undergoing extracorporeal membrane oxygenation (ECMO). A retrospective record review of 21 patients in the neonatal intensive care unit (mean ECMO initiation age, 2 days; range, 0-4 days; male/female ratio, 1:1) undergoing ECMO from 2006 to 2008 was performed. Linear regression correlations between anti-Xa, PTT, and ACT were determined by extrapolating PTT and ACT therapeutic ranges that corresponded with the ECMO heparin target range of 0.3 to 0.6 U/mL. Pearson correlation coefficients between heparin levels and PTT (-0.903 to 0.984), PTT less than 40 seconds after correction using PTT-heparinase (-0.903 to 1.000), and ACT (-0.951 to 0.891) in this patient population were widely variable. Inconsistency of PTT and ACT therapeutic ranges corresponding to heparin levels of 0.3 to 0.6 U/mL prompts a multifactorial approach to ECMO management because no single laboratory test can be used to determine appropriate anticoagulation management.

Publication types

  • Evaluation Study

MeSH terms

  • Anticoagulants / administration & dosage
  • Anticoagulants / blood*
  • Extracorporeal Membrane Oxygenation*
  • Factor Xa / analysis*
  • Female
  • Heparin / administration & dosage
  • Heparin / blood*
  • Hernia, Diaphragmatic / therapy
  • Humans
  • Hypertension, Pulmonary / therapy
  • Infant, Newborn
  • Male
  • Meconium Aspiration Syndrome / therapy
  • Partial Thromboplastin Time*
  • Reproducibility of Results
  • Retrospective Studies
  • Sepsis / therapy
  • Whole Blood Coagulation Time


  • Anticoagulants
  • Heparin
  • Factor Xa