Adjusting heparin infusion rates from the initial response to activated coagulation time.

A mathematical description of the dose-response curve of heparin to the activated coagulation time is applied retrospectively to 20 patients treated with continuous heparin infusion. The adjusted heparin dose was compared with a calculated prediction using the theoretical mathematical model. The main actual dose was 28 U/kg/h, and the mean predicted dose was 25.8 U/kg/h. The correlation coefficient was 0.862 (p3 0.05). These data are used to develop a dosing adjustment chart. Special considerations prior to using the calculation or dosing adjustment chart are discussed. The use of this model may allow the clinician to determine more rapidly a therapeutic heparin dosage than previous empiric approaches.