Sensitivity of the thrombin clotting time and activated partial thromboplastin time to low level of antithrombin III during heparin therapy.
The thrombin clotting time (TCT) has been used at our institution, along with the activated partial thromboplastin time (aPTT), for monitoring heparin therapy. We have observed that, in some patients, a discrepancy develops between the heparin levels predicted by the TCT and the aPTT with the TCT consistently predicting a lower heparin level than the aPTT. An inverse relationship was noted between the functional antithrombin III (AT-III) level and the magnitude of this discrepancy.
Delorme
M A
MA
Division of Hematology and Oncology, St. Joseph's Health Centre, University of Western Ontario, London, Canada.
Inwood
M J
MJ
O'Keefe
B
B
D000990:Antithrombin III / Q000494:pharmacology*; D020152:Antithrombin III Deficiency; D004305:Dose-Response Relationship, Drug; D006493:Heparin / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008991:Monitoring, Physiologic; D010314:Partial Thromboplastin Time; D011237:Predictive Value of Tests; D013918:Thrombin Time
D000990:Antithrombin III; D006493:Heparin