Therapy and Prevention - Cardiac Surgery

It has been suggested that desmopressin acetate (DDAVP) administration reduces blood loss after cardiac surgery. We have investigated the effect ofDDAVP administration in a double-blind, randomized, prospective trial including 100 patients placed on cardiopulmonary bypass during surgery. Fifty patients received 0.3 gg/kg DDAVP and 50 patients received a placebo administered in a 50 ml saline solution over 15 min when cardiopulmonary bypass had been concluded. Results showed no significant differences either in total blood loss per square meter (458 + 206 ml in the DDAVP group vs 536 ± 304 ml in the placebo group) or in necessity for red cell transfusions (1642 ± 705 ml in the DDAVP group vs 1574 ± 645 ml in the placebo group) in the first 72 hr after surgery. Only intraoperative blood loss per square meter was significantly lower (p < .02) in the DDAVP group (131 + 106 ml) as compared with the placebo group (193 + 137 ml). The prolongation of bleeding time and the decrease of factor VIII: C and factor VIII: von Willebrand factor 90 min after treatment were significantly lower (p < .001) in the DDAVP group as compared with the placebo group. We conclude that the administration of DDAVP in patients placed on cardiopulmonary bypass during surgery does not reduce total blood loss and is only elfective in reducing intraoperative bleeding. Circulation 77, No. 6, 1319-1323, 1988. PATIENTS placed on cardiopulmonary bypass (CPB) for open heart surgery have an increased susceptibility to postoperative bleeding.' Reoperation for bleeding control is sometimes necessary and occasionally lifethreatening hemorrhaging occurs during the postoperative period. The majority of patients bleed primarily from the operative site. However, in some patients, diffuse systemic bleeding2'3 suggests an acute acquired hemostatic defect. The basic pathophysiology of altered hemostasis associated with CPB remains confusing. The abnormalities most frequently found include heparin and protamine excess, heparin rebound, low platelet count, abnormal platelet function, low fibrinogen, primary fibrinolysis, and disseminated intravascular coagulation.4"'6 Since a significant platelet function defect may be the primary cause of hemorrhage, the use of platelet concentrateN and prostacyclin has been suggested.2', 17, A defect in ristocetin-induced platelet aggregation has been described in these patients,2 suggesting From the Hematology and Cardiovascular Surgery Services, University Clinic, University of Navarra, Pamplona, Spain. Address for correspondence: E. Rocha, M.D., Service of Hematology, University Clinic of Navarra, Apartado 192, 31080-Pamplona, Spain. Received Aug. 24, 1987; revision accepted Feb. 4, 1988. a role for von Willebrand factor in the hemostatic defect.'9 Recently, Salzman et al.20 showed that desmopressin acetate (DDAVP) reduced postoperative blood loss in patients undergoing CPB. They suggested that the elevation in the plasma concentration of von Willebrand factor induced by DDAVP, possibly in association with a change in the distribution of von Willebrand factor multimers, was the most likely explanation for the beneficial effect of the drug in CPB. However, it has been argued that the good results found by Salzman et al. may be related to the high postoperative blood loss reported in their patients.21 22 DDAVP is a synthetic analog of the neurohypophyseal nonapeptide arginine vasopressin. It is known that this hormone causes the appearance of larger von Willebrand's factor multimers in addition to increased concentrations of factor VIII: von Willebrand factor and factor VIII: C and thus a role for DDAVP has been indicated in patients with mild hemophilia or von Willebrand's disease.23 DDAVP has also been shown to shorten the bleeding time in other conditions, including uremia, chronic liver disease, and aspirin ingestion. 24-26 In the present study we evaluated the effectiveness of intraoperative DDAVP in the reduction of blood loss during the postoperative period in a double-blind, Vol. 77, No. 6, June 1988 1319 by gest on N ovem er 2, 2017 http://ciajournals.org/ D ow nladed from