Heparin activity monitoring during vascular surgery

Twelve patients undergoing vascular surgery were administered heparin according to preexisting protocols. The response to heparin and the rate of decay were measured by use of the activated coagulation time (ACT). The results showed a significant patient variability to response to and decay of heparin. In addition, a dose-response curve for heparin administration was established in sixteen patients undergoing vascular surgery. The ACT proved to be a simple and accurate monitor of heparin activity. It also made possible a steady state of anticoagulation throughout the duration of the vascular procedure. The reversal of the heparin effect could also be precisely determined by this test.