8 samples for each group met the requirement of power = 0.8 and α = 0.05 (two-sided). Group sample size was calculated based on the result of a pilot study, in which the mean CL was 0.007☐.002 (n = 5) L/kg/min in the obstructive jaundice group and 0.010☐.002 (n = 5) L/kg/min in the control group. The operator of drug concentrations analysis were blinded to the grouping. The main pharmacokinetic parameters: clearance (CL), terminal elimination half-life (T 1/2), Cmax, the area under the concentration-time curve (AUC) from zero to the last measurable plasma concentration point (AUC 0-t), AUC from 0 to infinity (AUC 0-∞), mean residence time (MRT), and volumes of distribution (V d) were calculated by non-compartmental analysis using Phoenix WinNonlin 7.0 (Pharsight Corporation, Mountain View, CA, USA). The intraday and interday coefficients of variation were 0.7% to 5.9% and 2.2% to 5.8%, respectively, for dexmedetomidine concentrations in the range of 0.01 to 10 ng/mL. Plasma dexmedetomidine concentrations were determined by 1290 infinity high performance liquid chromatography coupled with 6470 tandem mass spectrometry (iHPLC-MS/MS, Agilent Technologies, Santa Clara, CA, USA) with a lower limit of quantitation of 10 pg/mL. The room temperature was controlled at 22–24☌.īlood samples (using lithium heparin to anticoagulate) were kept on ice until centrifugation within 30 minutes, and plasma samples were stored at -80☌. Patients were divided into two groups according to total serum bilirubin (TBL): an obstructive jaundice group (TBL > 17.1μmol/L, n = 18) a control group (TBL 9.0 g/dL. Patients with known or suspected cardiac, pulmonary, renal, or metabolic disease, weight greater than +/-30% of ideal, and patients on any form of analgesic or neuro-modulating medication were excluded from this study. Written consent was obtained from all subjects. A total of 30 ASA I/II/III patients undergoing scheduled bile duct surgery, aged 40–70 years and weighing 45–80 kg, were recruited in this study during 2015. The registration number of clinical trial is ChiCTR-IPR-15007572. 225, Shanghai, China (EHBHKY-2) prior to its start. This study was approved by the Committee on Ethics of Biomedicine Research, Eastern Hepatobiliary Surgery Hospital, Changhai Rd., No.
0 kommentar(er)
