[How much dosage of heparin do you administer? The relationship between heparin dosage and activated coagulation time (ACT) value during cardiovascular surgery: a multi center investigations].

Background: In cardiac surgery, unfractionated heparin is widely used for anticoagulation. There are differences of heparin dosages among institutions for cardiac surgery with and without cardiopulmonary bypass (CPB). The aim of this clinical investigation is to find out the optimal dosage of heparin for initiation of CPB.

Methods: In cardiac cases with CPB, patients' weight, initial dosage of heparin, ACT values after heparin administration, product name of heparin and ACT measurement devices were recorded.

Results: There were significant differences in initial dosages of heparin, basal ACT values and increment of ACT values per units of heparin among institutions.

Conclusions: A significant difference was revealed among institutions regarding the initial heparin dosage for CPB, in spite of the same target of ACT. There was no evidence to determine the optimal dosage of heparin for initiation of CPB.