Heparin and Prostacyclin

Abstract

Hemodialysis performed with prostacyclin (5 ng/kg/min) as a sub stitute for heparin was studied in 10 patients. The subjects were studied during heparin perfusion alone and during heparin perfusion together with prostacyclin. The authors inves tigated the effect of two heparin regi mens (regimen I: 2,000 U/hr and reg imen II: 500 U/hr) upon plasma anti thrombin level (IU/mL) and activated thromboplastin time (sec). Our findings show: (1) prostacy clin can substitute for heparin anti coagulaton in hemodialysis; (2) the concomitant administration of pro stacyclin enhances the anticoagulant effect of heparin, based on the mea surement of the activated partial thromboplastin time; (3) the anti thrombin activity is increased by both treatments but more so with prostacyclin; and (4) platelet activa tion plays a role in limiting heparin anticoagulation, a conclusion partly supported by the finding that acti vated partial thromboplastin time is somewhat more prolonged by hepa rin when measured in platelet-poor rather than in platelet-rich plasma in the presence of prostacyclin. Physio pathologic implications of these pre liminary findings are discussed.