Currently, the activated Partial Thromboplastin Time (aPTT) is the laboratory test most commonly
used to monitor unfractionated heparin therapy. The Heparin Therapeutic Range is developed utilizing a procedure in which aPTT values and heparin levels are obtained from patients actually receiving heparin. A graph is prepared that correlates the aPTT in seconds to the heparin Anti-Xa units. The ranges established, are the time in seconds equivalent to 0.3 and 0.3 to 0.7 Anti-Xa units of heparin.
Refer to: Laboratory Monitoring of Heparin Therapy
However, prolongation of the aPTT does not necessarily indicate that the blood is effectively anticoagulated in vivo. A variety of conditions can complicate the administration and monitoring of unfractionated heparin therapy.
or contact laboratory [409-772-3314] for further recommendations.
Critical Values: > 100 seconds