BACKGROUND: Liver dysfunction has major impacts on the pharmacokinetics and pharmacodynamics of anesthetics. This study was designed to evaluate propofol concentrations during and at the end of total intravenous anesthesia (TIVA) for hepatectomy. METHODS: Fifty patients receiving hepatectomy (n = 25) or other epigastric surgeries (controls, n = 25) were anesthetized with TIVA. Fentanyl was injected repeatedly to insure maintenance of the effect-site concentration in the 2.0 to 2.5 ng x ml(-1) range with off line computer similation program. Propofol was administered with target-controlled infusion at the initial target concentration of 3.0 mcg x kg(-1), and then titrated to maintain bispectral index (BIS) values between 40 and 50. The intervals after propofol discontinuation to emergence and extubation and the predicted propofol and fentanyl concentrations were recorded. Propofol concentrations at emergence were measured with blood sample in eight cases. RESULTS: The propofol dose in hepatectomy patients as well as both measured and predicted concentrations of propofol at extubation, were lower than in control patients. The extubation time was longer in hepatectomy than in control subjects. CONCLUSIONS: Recovery from TIVA is delayed in hepatectomy patients. We speculate that this is attributable to altered pharmacodynamics in these patients.
BACKGROUND:Liver dysfunction has major impacts on the pharmacokinetics and pharmacodynamics of anesthetics. This study was designed to evaluate propofol concentrations during and at the end of total intravenous anesthesia (TIVA) for hepatectomy. METHODS: Fifty patients receiving hepatectomy (n = 25) or other epigastric surgeries (controls, n = 25) were anesthetized with TIVA. Fentanyl was injected repeatedly to insure maintenance of the effect-site concentration in the 2.0 to 2.5 ng x ml(-1) range with off line computer similation program. Propofol was administered with target-controlled infusion at the initial target concentration of 3.0 mcg x kg(-1), and then titrated to maintain bispectral index (BIS) values between 40 and 50. The intervals after propofol discontinuation to emergence and extubation and the predicted propofol and fentanyl concentrations were recorded. Propofol concentrations at emergence were measured with blood sample in eight cases. RESULTS: The propofol dose in hepatectomy patients as well as both measured and predicted concentrations of propofol at extubation, were lower than in control patients. The extubation time was longer in hepatectomy than in control subjects. CONCLUSIONS: Recovery from TIVA is delayed in hepatectomy patients. We speculate that this is attributable to altered pharmacodynamics in these patients.