ABSTRACT
Objective To investigate the effect of preoperative single target administrating of fibrinogen(FIB)on the intraop-erative bleeding and coagulation function in posterior lumbar interbody fusion (PLIF)operation.Methods 60 cases of lumbar inter-vertebral disc herniation(LDH)undergoing elective PLIF operation were divided into two groups according to the preoperative FIB levels:normal control group(NC,FIB≥3.0 g/L,n=20)and low FIB group(FIB<3.0 g/L,n=40).The low FIB group was ran-domly re-divided into 2 groups:the low HIB control group(LC,n=20)and the preoperative single FIB administrating group(PF, n=20).After anesthesia induction,the PF group was given FIB;the LC and NC groups were given the same volume of saline solu-tion as solvent volume required by administrating FIB dose.The change of blood coagulation 4 indexes were detected and the activa-ted clotting time(ACT),coagulation time(CR)and platelet function(PF)were detected by the sonoclot analyzer before and after drug administrating.The bleeding amount was weighed after ending operation.Results The FIB concentration after administrating in the PF group was (3.75±0.23)g/L,which was significantly higher than (2.62±0.33)g/L in the NC group and (2.23±0.22) g/L in the LC group,the differences among 3 groups were statistically significant(P <0.05);the CR value after administrating in the PF group was (21.42±7.15)U/min,which was higher than (18.21±5.62)U/min in the NC group and (15.21±5.63)U/min in the LC group.The bleeding amount in the PF group was (516.74±135.53)g,which was lower than (660.71±119.34)g in the NC group and (726.72±160.47)g in the LC group,the difference among 3 groups had statistical significance(P <0.05).Conclusion Preoperative single target administrating of fibrinogen can effectively increase the FIB level,improve the blood coagulation func-tion and reduce the periaoperative bleeding amount.
ABSTRACT
Objective To investigate the sedative and hypnotic interaction between remifentanil and propofol by target-controlled infusion (TCI) during induction of anesthesia.Methods Third-two ASA Ⅰ or Ⅱpatients,aged 22-63 yr,body mass index 18-25 kg/m2,scheduled for elective surgery under general anesthesia,were randomly divided into 4 groups(n=8 each).Group Ⅰ only received TCI pmpofol.GroupⅡ,Ⅲ,and Ⅳreceived a target concentration of 2,4 or 6 ng/ml remifentanil respectively.While the blood-effect site concentrations of remifentanil were equilibrated,patients received TCI of propefol,with an initial target concentration of 0.5μg/ml.After the blood-effect site concentrations of propofol were equilibrated then with 0.5μg/ml increments until the loss consciousness was achieved.The eyelash reflex and state of consciousness were assessed and radial arterial blood sample 6 ml was taken every 3 min to determine the remifentanil and propofol concentrations in blood.Propofol and remifentanil concentrations in blood were measured by reversed-phase high-performance liquid chromatography and high-performance liquid chromatography with ultraviolet detection respectively.The sedative and hypnotic interaction between propofol and remifentanil was determined with a pharmacodynamie interaction model by regression analysis and determined using the isobolographic method.Results Propofol concentrations in blood were lower in group Ⅱ,Ⅲ and Ⅳ than group Ⅰ(P<0.05).The propofol concentratopms in blood were significantly decreased in trun with the increase in the remifentanil concentrations in blood in group Ⅱ-Ⅳ(P<0.05).At loss of eyelash reflex and loss of consciousness of patients,the pharmacodynamic interaction model by curve fitting was superior to linear regression (P<0.05).At loss of eyelash reflex of patients,the curve fitting result showed EC50,prop=2.77μg/ml and EC50,rem=26.67 ng/ml,and the isobolographic method equation is ECprop/2.77+ECrem/26.67=0.69.At loss of consciousness of patients,the curve fitting result showed EC50,prop==3.76μg/ml and EC50,rem=31.56ng/ml,and the isobolographic method equation is Ecprop/3.76+Ecrem/31.56=0.65.Conclusion Remifentanil (Cp 2-6 ng/ml) and propofol by TCI shows a synergistic type of pharmacodynamic interaction on the sedative and hypnotic during induction of anesthesia.
ABSTRACT
OBJECTIVE To establish an assay for the simultaneous determination of propofol and lidocaine in human plasma using reversed-phase high performance liquid chromatography（RP-HPLC）.METHODS With thymol and bupivacaine as the internal standards for propofol and lidocaine respectively,the extraction was performed with cyclohexane.The organic layer was evaporated and the residue was redissolved by mobile phase.The concentrations of propofol and lidocaine were assayed on a hypersil BDS C18 column with a mobile phase consisting of acetonitrile-methanol-water（10∶60∶30）（including 0.14% n-butyamine 0.1% acetic acid）at a flow rate of 1 mL*min-1 and detected at 220 nm during 1～7 min and at 273 nm during 7～16 min.RESULTS The linearity between concentrations and peak area ratio was obtained from 0.1 μg*mL-1 to 25.6 μg*mL-1（r=0.998，r=0.9995）.The detection limits were 0.1 μg*mL-1 for propofol and 0.05 μg*mL-1 for lidocaine.The within-day and between-day variation coefficients were less than 5%(n=5).The average recoveries were 93.33%,99.4% and 90%,95.67% respectively.CONCLUSION The method was found to be rapid,accurate and precise.It is suitable for clinical pharmacokinetic and pharmacodynamic study.
ABSTRACT
Objective To study the influence of age on the pharmacodynamics of propofol including the relationship between plasma concentrations of propofol and the time of loss of consciousness or return of consciousness.Methods Forty-two ASAⅠ-Ⅱ patients were assigned to one of three age groups: group A: age ranged from 18-34 yr(n=14); group B:35-60 yr(n=15); and group C: 61-90 yr(n=13). Once spinal anesthesia was completed, propofol infusion at the rate of 0.5 mg?kg -1?min -1(group A) or 0.4 mg?kg -1?min -1(group B and C )was started until burst suppression of EEG lasting 3s was observed. Venous blood samples were taken at 1, 2, 4, 8,10, 15, 30, 45,60,90,120 and 240 min after the start of propofol infusion for the determination of plasma propofol concentrations. The influence of age on relationship between propofol plasme concentration and loss of consciousness or return of consciousness was analyzed by non-linear regression. The relationships between age and time of loss of consciousness,duration of sleep,the total dose of propofol,the plasma concentration at the time of loss of consciousness or return of consiousness were determined by linear regression.Results As compared with those in group A and B,the time of loss of consciousness and the total dose of propofol required decreased markedly in group C. The observation showed increased sensitivity to propofol in elderly patients. The EC50 values for loss of consciousness were 2.86 (at age of 25 yr),2.26 (at 50yr), and 1.78 (at 75yr) ?g?ml -1,and the EC50 values for return of consciousness of 1.76 (at 25 yr),1.45(at 50yr),1.11(at 75yr)?g?ml -1 respectively.Conclusions Elderly patients are more sensitive to propofol than younger people in terms of hypnosis and EEG effects.
ABSTRACT
OBJECTIVE:To study the accuracy of infusion of Midazoloam with plasma concentration as target. METHODS:The parameters of Midazoloam obtained from our researches were inputted into target-controlled infusion(TCI) system with C language. The clinical anesthesia of 12 patients undergoing selective operations was completed with plasma concentration as target-controlled infusion. Predicted value of plasma concentration of Midazoloam was compared with measured value. Parameters of Midazoloam sample were calculated such as performance error(PE),absolute performance error(absPE),median performance error(MDPE),median absolute performance error(MDAPE),constancy error(CE),absolute constancy error(absCE),median constancy error(MDCE) and median absolute constancy error(MDACE). RESULTS:PE,absPE,MDPE and MDAPE of plasma concentration were -2.57%,14.16%,-3.28% and 15.34%,respectively. CE,absCE,MDCE and MDACE were 0.06%,1.42%,0.03% and 1.21%,respectively. The measured values were in indirect relationship with predicated values(r=0.986,P