Vol 1, No 1 (2010)
Review paper
Published online: 2010-02-04
Diagnosis of the prolonged activated partial thromboplastin time (aPTT)
Hematologia 2010;1(1):81-86.
Abstract
The aPTT is one of the most widely used global tests for blood coagulation. Indications for
ordering aPTT include preoperative hemostasis screening, initial evaluation of hemorrhage
and monitoring of heparin administration. The most common causes of aPTT prolongation
are deficiencies or inhibitors of clotting factors. An unexpectedly prolonged aPTT is quite often
connected with artifactual causes. In this paper we review the essential factors affecting aPTT
results and provide a practical approach to the evaluation of a prolonged aPTT.
Keywords: activated partial thromboplastin timeprothrombin timecoagulation factor deficienciesacquired inhibitors of coagulation