Influence of heparin dosage on hemostasis under combined use of Nafamostat mesilate during deep hypothermic circulatory arrest.

OBJECTIVE: Nafamostat mesilate (NM) is a guanidine acid derivative which is synthesized in Japan as an antifibrinolytic drug. It has been successfully used to decrease blood loss and blood product requirement in cardiac operations. As there have been some reports that insufficient heparinization might induce the coagulopathic state in aprotinin-treated patients undergoing deep hypothermia and circulatory arrest (DHCA), we have reviewed 16 consecutive patients who underwent total aortic arch replacement using DHCA and the associated use of NM.
METHODS: The patients were divided into two groups; a Normal-dosage Group (n = 8) who received 3 mg/kg of heparin, and a Low-dosage Group (n = 8) who received 1.5 mg/kg of heparin. The Celite-activating clotting time was maintained at longer than 1,000 seconds in both groups. Blood loss, transfusion requirements and the volume of postoperative mediastinal tube drainage were compared between the two groups.
RESULTS: We observed no adverse effects of NM and no significant difference in transfusion requirements between both groups. There was a significant difference in blood loss during the operation between the two groups (p < 0.05) (Low-dosage Group 1,973 +/- 959 ml vs Normal-dosage Group 1,059 +/- 704 ml).
CONCLUSIONS: NM was a safe antifibrinolytic drug. Adequate heparinization was necessary to reduce hemorrhage in patients undergoing aortic arch replacement using DHCA and the associated use of NM.