A COMPARISON OF HEMOSTATIC PARAMETERS IN HYPOTHERMIC VERSUS NORMOTHERMIC CARDIOPULMONARY BYPASS

Ten patients who underwent PCPS (group A) at our institution were eval uated for hemostatic abnormalities and compared to an age matched popu lation undergoing open CPB (group B) to study the effects of CPB indep endent of the effects of hypothermia. Both groups had hemostatic param eters measured prior to, 1 hour after, and 16-24 hours following compl etion of the procedure. The mean duration of perfusion for group A was 53.7 +/- 13.5 minutes and group B 108.1 +/- 26.5 minutes (P < 0.0001) . There were no significant differences in hemoglobin, platelet count, congulation factors, and rests of in vitro platelet function between groups A and B at the different rime points. While bleeding times for group B returned to baseline within an hour following bypass, they rem ained significantly prolonged in group A 24 hours later (P = 0.02). Co nclusion: Normothermic bypass used during PCPS results in platelet fun ction abnormalities similar to open hypothermic CPB suggesting the dom inant role of the membrane oxygenator over hypothermia in inducing the platelet dysfunction.