ABSTRACT
BACKGROUND: Hypertension following coronary artery bypass graft surgery (CABG) occurs frequently. Pharmacologic therapy of postoperative hypertension has often been treated with sodium nitroprusside (SNP). Nicardipine which is a dihydropyridine calcium-channel blocker, has little or no direct negative effects on cardiac contractility. Thus, we have compared the effects on hemodynamics between nicardipine and SNP after a CABG. METHODS: After a CABG, when systolic blood pressure (SBP) was elevated above 140 mmHg, patients were randomized to receive either nicardipine (N-group, n = 26) or SNP (S-group, n = 21) at an initial rate of 2ng/kg/min until the SBP was lowered to 120 130 mmHg (target blood pressure, TBP) for 10 minutes. If the TBP was not achieved, the infusion rates of both drugs were increased by 1ng/kg/min every 10 minutes. If SBP was lowered below 100 mmHg, phenylephrine was infused. Hemodynamic measurements were obtained just before (T1) and at 10 min (T2), 60 min (T3) and 24 h (T4) after the infusin of nicardipine or SNP. Infusion time, total doses, creatine phosphokinase (CK)-MB, plasma catecholamine and the use of phenylephrine were compared between groups. RESULTS: The SBP and systemic vascular resistance were significantly decreased in both groups. The cardiac index and stroke volume index were significantly increased at T3 in both groups but they were significantly increased only in the N-group at T2. The infusion time and the total doses of both drugs were significantly less in the N-group than the S-group. There were no significant differences in CK-MB, plasma catecholamine and the use of phenylephrine between groups. CONCLUSIONS: It has been suggested that the infusion of nicardipine is as effective as the infusion of SNP for the control of postoperative hypertension and the increase of cardiac output after a CABG. However, immediately after the drug infusion, nicardipine was superior to SNP in maintaining left ventricular performance.