A COMPARISON BETWEEN ARTERIAL-SAMPLED AND VENOUS-SAMPLED ACTIVATED CLOTTING TIME MEASUREMENTS

In order to compare activated clotting time (ACT) sampled from an arte rial (heparin-flushed) line with the control, a venous (heparin-free) line, arterial and venous ACT values were assessed before and after ca rdiopulmonary bypass in 150 patients while undergoing open-heart surge ry. ACT was measured by Hemochron(R) 801 automatic analyzer. Baseline arterial ACT was significantly higher than baseline venous ACT (14%; p <0.001, using one-way analysis of variance and Bonferroni multiple com parisons test). The differences between the values of arterial and ven ous ACT after protamine reversal, between arterial ACT at baseline and after protamine reversal, and between venous ACT at baseline and afte r protamine reversal were not statistically significant. We conclude t hat arterial-sampled ACT measurement is suitable and reliable for moni toring heparin reversal by protamine after cardiopulmonary bypass.