Effect of nicardipine on hepatic blood flow in patients undergoing cardiac valve replacement with cardiopulmonary bypass

Abstract

Objective To investigate the effect of nicardipine on the hepatic blood flow in the patients undergoing cardiac valve replacement with cardiopulmonary bypass(CPB). Methods Twenty-six patients of both sexes, aged 30-64 yr, weighing 50-90 kg, with New York Heart Association Ⅱ or Ⅲ, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, scheduled for elective mitral or aortic valve replacement, were randomly divided into either nicardipine group(group P, n=13)or control group(group C, n=13)using a random number table.Transesophageal echocardiography was used to measure the indexes of blood flow in the hepatic vein.Nicardipine 0.2-0.5 μg·kg-1·min-1 was infused intravenously starting from beginning of CPB, and the infusion was stopped at termination of CPB in group P. After induction of general anesthesia, at 30 min after beginning of CPB, at 10 min before termination of CPB, and at 30 min after termination of CPB, the diameter of the right and middle hepatic veins(DR and DM), blood flow index in the right hepatic vein(QIR), blood flow index in the middle hepatic vein(QIM), and total blood flow index in the hepatic vein(QIR+ M)were recorded, and the percentage of QIR+ M in cardiac index(CI)(QIR+ M/CI)or in QICPB(QIR+ M/QICPB)was calculated.Before operation, and at 1 and 2 days after operation, blood samples were obtained from the median cubital vein for determination of total bilirubin, alanine aminotransferase, and aspartate aminotransferase(AST)levels in serum. Results Compared with group C, the serum levels of AST at 1 day after operation and serum levels of AST at 1 day after operation were significantly decreased(P 0.05). Conclusion Nicardipine(0.2-0.5 μg·kg-1·min-1)infused intravenously during CPB exerts no effect on the hepatic blood flow, and it is not related to the improvement in hepatic function in the patients undergoing cardiac valve replacement. Key words: Nicardipine; Cardiopulmonar bypass; Heart valve prosthesis implantation; Liver; Hemodynamics