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ObjectiveTo study the pharmacokinetics of sufentanil in patients undergoing different cardiac surgeries with or without CPB.MethodsSixteen ASA Ⅱ or Ⅲ patients aged 56-64 yr weighing 52-78 kg undergoing cardiac surgery were divided into 2 groups ( n ＝ 8 each):group Ⅰ off-pump coronary artery bypass grafting and group Ⅱ valve replacement.Radial artery and peripheral vein were cannnlated.A bolus of sufentanil 5μg/kg was administered iv after induction of anesthesia.Blood samples were obtained from radial artery at 1,3,5,10,20,30,60,120,180,240,360 min after sufentanil injection.Plasma was immediately separated and stored at - 80 C for determination of plasma sufentanil concentration by liquid c hromatography-mass spectrometry.Pharmacokinetic parameters were calculated by 3P97 pharmacological program.ResultsThe pharmacokinetic profile of sufentanil was best described by a three-compartment open model.The 3 exponential equations in group Ⅰ,before and during CPB in group Ⅱ were:Cp(t) ＝ 11.7 e-0.47t + 1.9 e0.043t + 0.27 e-0.0032t ; Cp(t) ＝ 33.4 e-1.87t + 7.1e-0.103t +2.0 e-0.0248t and Cp(t) ＝ 23.8 e-0.54t + 5.2 e0.054t + 0.15 e-0.0017t respectively.There was significant difference in most of the pharmacokinetic parameters between the 2 groups.ConclusionsThe pharmacokinetics of sufentanil in patients undergoing different cardiac surgeries can be described by ~compartment open model.Low cardiac function and CPB can reduce its drug metabolism rate and prolong the duration of action.
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Objective To investigate the pharmacodynamics characteristics of continuously infused cisatracurium besylate during total intravenous anesthesia. Methods Sixty ASA Ⅰ - Ⅱ patients undergoing elective oromaxillo-facial region surgeon were randomly divided into 4 groups. 1.0, 2.0, 3.0 μg/ (kg · min ) of cisatracurium besylate was continuously infused differently in group Ⅰ, group Ⅱ and group Ⅲ, and 0.1 mg/kg of cisatracurinm besylate was injured interruptedly into group Ⅳ after anesthesia induction. Neuromuscular function was assessed using an accelerometer with train-of-four (TOF) stimulation, the maximum depression of T1and times to T1 recovered to 25%(the clinic time), 75%, 90%(the vivo time) were noted. The recovery index (time of T1 recovery from 25% to 75%) was also calculated. Results The drug consumptions of cisatracurium besylate in group Ⅰ and group Ⅱ were diminished than those in group Ⅲ and group Ⅳ [(59.1±9.6),(116.7±11.5)μg/kg vs (174.9±23.1), (177.2±20.4) μg/kg](P<0.01), and group Ⅲ and group Ⅳ were nearly (P>0.05 ). The maximum depression of T1, the clinic time and the vivo time in group Ⅰ, Ⅱ,Ⅲ were smaller than those in group Ⅳ [ ( 18.5±3.6)%, (6.4±2.7)%, 0 vs (25.0±0.0)% ] (P < 0.01 ), but there were. No significant differences in recovery index in 4 groups. The maximum depression was diminished (P< 0.01 ) and the clinic time and the vivo time were prolonged (P<0.05) with the inerease of the dosage of cisatracurium besylate in group Ⅰ, Ⅱ, Ⅲ. Conclusions With no cumulative effect, the duration of recovery of muscle relaxation is shortened and the recovery index of continuously infused eisatracurium besylate is prolonged. It indicates that the cisatracurium besylate is suitable for the continuously infusion for surgeon patients.
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Objective To evaluate the pharmacokinetics of ropivacaine following lumbar plexus combined with sciatic nerve block for knee arthroscopy. Methods After obtaining written informed consent 16 ASAⅠorⅡpatients of both sexes (8 males ,8 females) scheduled for unilateral knee arthroscopy under lumbar plexus combined with sciatic nerve block with ropivacaine were randomly divided into 2 groups (n = 8 each) : group A received 0.5% ropivacaine 30 ml (15.0 mg) and group B received 0.75% ropivacaine 30 ml (22.5 mg) . Blood samples were taken from radial artery immediately after and at 5, 10, 15, 30, 45, 60, 120 and 180 min after drug administration for determination of plasma ropivacaine concentration by HPLC. The pharmacokinetic parameters were calculated using 3p97 computer program. Results The two groups were comparable with respect to sex ratio (M/F), age, body weight, height, duration of operation and amount of fluid infused. The main pharmacokinetic parameters in group A and B were: Cmax(1.4?0.3) mg?L-1 and (2.7?0.9) mg?L-1;AUC (3.88?0.28) mg?L-1?h-1 and (7.13?0.65) mg?L-1?h-1;t1/2?(0.44?0.19)h and (0.60?0.34)h; t1/2?(3.4?0.4)h and (2.4?0.5)h. The Cmax in group B was significantly higher than that in group A. The Cmax of ropivacaine reached 3.57 mg?L-1 in group B. No patient developed central nervous system or cardiac toxicity.Conclusion The plasma concentration versus time curve is fitted to two-compartment pharmacokinetic model. Lumbar plexus combined with sciatic nerve block with 0.5% ropivacaine 30 ml is safer.