Summary
Twenty patients undergoing aorto-coronary bypass were randomly assigned to a prostacyclin
treatment group or control group. Eight patients received 2mg/kg heparin and 10 ng/kg/
min prostacyclin before cardiopulmonary bypass (CPB) and 50 ng/kg/min during CPB.
Twelve patients, serving as controls, received 3mg/kg heparin. Heparinization resulted
in a slight but significant increase of plasma beta-thromboglobulin in the control
group but not in the prostacyclin group, and of plasma platelet factor 4 (PF-4) in
both groups. After 90 minutes of CPB, beta-thromboglobulin was 408 (SD 128) ng/ ml
in the control group and 111 (SD 50) ng/ml (p < 0.001) in the prostacyclin group.
Platelet count, corrected for hemodilution, was 92% (SD 10) of the pre-CPB value after
10 minutes of CPB and 89% (SD 7) one hour after CPB in the control group, as compared
to 113% (SD 10) and 145% (SD 18), respectively, in the prostacyclin group.
Prostacyclin infusion before CPB reduced systemic vascular resistance to half of that
of the control group, lowered mean arterial blood pressure, and increased cardiac
index by 60% to 80%. An infusion of prostacyclin before CPB does not add to the already
excellent platelet protective effect of 50 ng/kg/ min prostacyclin during CPB, but
may be used for vasodilation.
Key words
Prostacyclin - Cardiopulmonary bypass - Platelets - Hemodynamics
