The haemodynamic effects of sodium nitroprusside following cardiopulmonary bypass: a clinical study.
Measurements of cardiac index were made in 18 patients (14 male and 4 female) preoperatively and thereafter during a 12-hour period immediately following coronary artery bypass grafting for stable angina pectoris. Patients with evidence of impaired left ventricular function were not included in the study. Individuals were allocated randomly to one of two groups. The first group received sodium nitroprusside as a constant, variable dose infusion during the post bypass study period (nitroprusside group). The second group received no nitroprusside (control group). The operative and postoperative management of these patients was otherwise identical. Following bypass, both groups showed a gradual drop in cardiac index with an associated increase in peripheral vascular resistance. In the control group, the mean cardiac index fell below the mean preoperative value. In the nitroprusside group, however, the mean cardiac index always remained above the mean preoperative level for the group, the differences between the groups being statistically highly significant at 1 1/2 hours postoperatively (p less than .005) and still significant at 3 hours postoperatively (p less than .05). The subsequent rise in cardiac index over the next 9 hours was more rapid in the nitroprusside treated patients and left ventricular function was better as demonstrated by a consistently higher mean cardiac index for any given left ventricular filling pressure. It is concluded that nitroprusside increases cardiac output and improves left ventricular function in the early postoperative period following cardiopulmonary bypass.
D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output; D002315:Cardiopulmonary Bypass; D002496:Central Venous Pressure / Q000187:drug effects; D002986:Clinical Trials as Topic; D005292:Ferricyanides / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology*; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D011897:Random Allocation
D005292:Ferricyanides; D009599:Nitroprusside