HEMODYNAMIC CONSEQUENCES OF DESMOPRESSIN ADMINISTRATION AFTER CARDIOPULMONARY BYPASS

Desmopressin acetate is used to reduce blood loss after cardiac surgery. However, there have been reports that hyopotension can occur with infusion of desmopressin and that postoperative blood loss is not reduced. In this randomized, double-blinded study, we investigated the effects of desmopressin on hemodynamics, coagulation, and postoperative blood loss in patients undergoing primary elective coronary artery bypass grafting (CABG). After reversal of heparin effect, 20 patients received desmopressin 0.3-mu-g.kg-1, infused over 15 min, and 20 patients received a placebo. Desmopressin produced a small but significant decrease in diastolic blood pressure when compared with the placebo (50.8 mmHg vs. 57.6 mmHg for the desmopressin- and placebo-treated groups, respectively; P = 0.0372). A 20% or greater decrease in mean arterial pressure was observed in 7 of 20 patients receiving desmopressin, whereas only one patient in the placebo-treated group experienced a decrease of this magnitude (P = 0.0177). Reductions in arterial pressure were secondary to decreases in systemic vascular resistance (SVR) (mean SVR before and after the drug infusion, 1,006 and 766 dyn.s.cm-5, respectively, for the desmopressin-treated group; and 994 and 1,104 dyn.s.cm-5, respectively, for the placebo-treated group; P = 0.0078). In addition, desmopressin did not reduce postoperative blood loss (mean 24-h mediastinal blood loss, 790 ml vs. 687 ml for the desmopressin- and placebo-treated groups, respectively), improve the postoperative bleeding time (mean times of 8.3 min vs. 9.0 min for the desmopressin- and placebo-treated groups, respectively), or enhance coagulation (mean prothrombin time, 14.2 s vs. 13.5 s and, mean partial thromboplastin time, 46.0 s vs. 45.5 s for desmopressin- and placebo-treated groups, respectively) in patients undergoing primary CABG. The authors conclude that intravenous infusion of desmopressin reduces SVR, often leading to hypotension, and does not reduce postoperative blood loss in patients having uncomplicated CABG.