Real time measurement of heparin concentration during cardiopulmonary bypass

Background A heparin/protamine titration system for measurement of heparin levels (Hepcon) is promising for efficient anticoagulation during cardiopul monary bypass (CPB). Methods. Fifty-seven patients subjected to CPB were divided into two groups , control (n=24) and Hepcon groups (n=33), The Hepcon group was further div ided into three subgroups according to perfusion temperature. For the contr ol group, conventional administration of an anticoagulant (300 IU/kg of hep arin) and reversal protocol (heparin 1: protamine 1) was performed. For the Hepcon group, a heparin dose-response assay directed the initial dose of h eparin, Hepcon also determined the dose of protamine by the titration. The initial dose of heparin in the control group (300 IU/kg) was statistically less than that of Hepcon group (360+/-80 IU/kg). Results. In the Hepcon group, the sensitivity to heparin was correlated wit h coagulation time (r=-0.78) and antithrombin III levels (r=0.70), and indi vidual difference of sensitivity resulted in a wide range of dosage (160 to 490 IU/kg). A strong correlation was observed between plasma and whole blo od concentration of heparin (r=0.86). However, they did not correlate with ACT values. Perfusion temperature didn't affect the heparin level, but did the ACT value. In the Hepcon group, the dose of protamine was significantly less and adverse events were rare. Conclusions. In conclusion, whole blood heparin measurements correlated wel l with plasma heparin concentration. Protamine titration of heparin reduced the dose of protamine and decreased the chance of adverse reactions.