Pharmacokinetics of propofol infusion in Asian patients undergoing coronary artery bypass grafting.
The pharmacokinetics of propofol was studied in 11 Asian patients with fentanyl-isoflurane anaesthesia during cardiopulmonary bypass (CPB) and undergoing elective coronary artery bypass grafting (CABG). Instead of the usual increments of morphine and a benzodiazepine, propofol (4 mg/kg/h) was initiated at the start of CPB and ceased at CPB separation. Whole blood propofol concentrations were determined during and postinfusion using high-performance liquid chromatography with fluorescence detection. Data from four patients seemed to fit a two-compartment model, whereas those from seven patients were significantly (F test, p < 0.05) better fitted to a three-compartment model. The pharmacokinetic parameters were as follows: The mean (SD) of the initial distribution phase t1/2 pi, intermediate distribution phase t1/2 alpha, and elimination phase t1/2 beta were 2.22 (1.04) min, 42.9 (16.4) min, and 370 (138) min, respectively. The mean clearance of 1.31 (0.50) L/min was lower than those reported from other studies, whereas the mean blood concentration of 2.2 (1.0) mg/L at the 1-h infusion period was higher. The mean calculated apparent Css was 3.9 (1.5) mg/L. The low clearance is likely to be due to hemodynamic changes during CPB and CABG, thereby affecting drug distribution and blood flow to the liver.
D000368:Aged; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002681:China / Q000208:ethnology; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D007214:Indonesia / Q000208:ethnology; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D012846:Singapore
D018686:Anesthetics, Intravenous; D015742:Propofol