ABSTRACT
In the prebypass preparation of patients it is crucial that heparinization is adequate. Confusion reigns in the literature as to heparin regimen and appropriate levels of heparin effect as measured by the activated clotting time [Hemochron]. We studied 40 patients and measured activated clotting time [ACT] values after two different dosage regimen, i.e. 300 units/kg body weight of heparin [20 patients] or 15000 units/m2 of heparin [20 patients]. At the end, heparin was neutralized with 3 mg/kg body weight protamine sulphate in all 40 patients, regardless of the total heparin dose. Thirty two% of patients had ACT levels less than 400 seconds prebypass who received heparin in the dose of 300 units/kg body weight. From this study it is concluded that that the opitmal loading dose of heparin be 15000 units/m2 and ACT levels be monitored every half hour while on cardiopulmonary bypass