Comparing the prothrombin time INR versus the APTT to evaluate the coagulopathy of acute trauma

Shan Yuan, Chris Ferrell, Wayne L. Chandler

Research output: Contribution to journalArticlepeer-review

107 Scopus citations


Introduction: In trauma patients, PT/INR or aPTT cutoffs of ≥ 1.5× normal are often used as triggers for the transfusion of plasma. Material and methods: To evaluate the ability of the PT/INR or aPTT to predict low coagulation factor levels, these tests were compared to coagulation factor levels in samples with artificially prepared single and multiple factor deficiencies, 9 heparin-contaminated samples, 10 lupus inhibitor-containing samples, 21 samples with elevated factor VIII levels, and 35 samples from acute trauma patients. Results and conclusions: The PT/INR and aPTT showed comparable sensitivity for single or multiple factor deficiencies in artificially deficient plasmas, but the PT/INR was more sensitive than the aPTT to low coagulation factor levels in actual trauma patients (sensitivity 84% versus 50%). The aPTT can show false positives with lupus anticoagulants and heparin contamination and false negatives in samples with elevated factor VIII. Thus, in the acute trauma setting, the PT/INR cutoff is a more reliable indicator of reduced coagulation factor levels.

Original languageEnglish (US)
Pages (from-to)29-37
Number of pages9
JournalThrombosis Research
Issue number1
StatePublished - 2007


  • activated partial thromboplastin time
  • aPTT
  • Coagulation factor
  • Hemostasis
  • INR
  • International normalized ratio
  • international normalized ratio
  • Prothrombin time
  • prothrombin time
  • PT
  • Trauma

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Hematology


Dive into the research topics of 'Comparing the prothrombin time INR versus the APTT to evaluate the coagulopathy of acute trauma'. Together they form a unique fingerprint.

Cite this