IN-VIVO LEFT-VENTRICULAR ASSIST INDUCED COAGULATION DERANGEMENTS - COMPARISON OF SARNS-3M AND ST. JUDE MEDICAL CIRCUITS

An in vitro comparison of centrifugal pumping systems manufactured by Sarns-3M and St. Jude Medical revealed a difference in blood cell dera ngement. The purpose of this study was to compare in vivo the effects of 96 hr of left ventricular assist (LVA) on indexes of coagulopathy, hemolysis, and complement activation. Two groups of calves (each: n = 5) were instrumented with identical left atrial to thoracic aorta cent rifugal pumping circuits using either Sarns-3M or St. jude centrifugal pumps. Laboratory evaluations were performed pre-assist and at 1, 4, 24, 48, 72, and 96 hr during LVA. Platelet counts dropped significantl y by 24 hr (Sarns-3M: 28%; St. Jude: 30%); no significant change in fu nction was noted. Activated clotting time increased slightly (p > 0.05 ). Prothrombin time increased at 4 and 24 hr of LVA, returning to base line by 96 hr (p < 0.05). Activated partial thromboplastin time increa sed with the St. jude device from 24 to 96 hr on LVA (p < 0.05); the i ncrease with the Sarns-3M device never reached significance. No signif icant changes in lactate dehydrogenase or plasma free hemoglobin were detected. Complement fraction C5a rose by 1 hr of LVA (p < 0.05), peak ing at 4 hr and returning to baseline by 96 hr with both pumps. No sig nificant difference was detected between pump groups for any of the pa rameters. it was concluded that 1) 96 hr Sarns-3M and St. Jude LVA cau sed coagulation derangement in calves, 2) neither pump demonstrated an advantage regarding coagulation and complement parameters, 3) hemolys is observed with the Sarns-3M pump in vitro was not evidenced in vivo, and 4) in vitro evidenced centrifugal pump differences may not be rea lized in vivo.