A simplified method for monitoring heparin therapy at the bedside: the activated whole blood clotting time.

Twelve patients receiving heparin during hemodialysis had coagulation parameters monitored using the whole blood clotting time (WBCT), activated partial thromboplastin time (APTT), plasma heparin levels and activated whole blood clotting time (AWBCT). The AWBCT, performed with a battery-powered portable incubator/timer, correlated with both the corresponding WBCT and the plasma heparin levels. However, the correlation between the AWBCT and the APTT was quite poor. This assay is simply performed, inexpensive, and reproducible. It is recommended as an excellent method for monitoring heparin therapy.