Abstract
Hemodynamic and metabolic effect of nitroprusside (NP) under the condition of cardiopulmonary bypass (CPB) were evaluated in this study. The changes of systemic vascular resistance (SVR), VO2and oxgen extraction ratio were compared before and after the administration of NP during CPB in 30 patients of aquired heart disease. SVR changed from 31.3±8.1 to 25.6±6.4 dynes·sec·cm-5 (p<0.005), VO2significantly increased from 50.7±14.0 to 58.8±21.0 ml/min/m2 (p<0.05) and oxygen extraction ratio from 20.0±4.7 to 24.3±7.1 % (p <0.05) after administration of NP. However, there were no statistical changes in the serum concentration of catecholamine and renin. Urinary excreta and rewarming time during extracorporeal circulation were compared with these 30 patients (Group NP) to 20 control patients without administration of NP (Group C) . Although no difference were seen in urinary excretition (403 ml/hour in group C, 395 ml/hour in group NP), rewarming time was shorter in group NP (48.2 min and 38.5 min, p<0.05) . Early post operative cardiac function at ICU were slightly better in group NP. These results suggested the administration of NP during CPB maintenance improved the demand supply balance of oxygen.
