ABSTRACT
Objective To evaluate the effect of age on the median-effective target plasma concentration (EC50) of propofol inhibiting body movement evoked by gastroscopy in the patients.Methods Ninety adult patients of both sexes,of ASA physical status Ⅰ or Ⅱ,with body mass index 19-25 kg/m2,scheduled for elective gastroscopy,were divided into 3 groups according to age (n =30 each):18-39 yr group (Ⅰ group),40-64 yr group (Ⅱ group) and 65-85 yr group (Ⅲ group).In Ⅰ,Ⅱ,Ⅲ groups,propofol was given by target-controlled infusion with the initial target concentrations of 2.5,2.0 and 1.5 μg/ml,respectively,and gastroscopy was performed when the target concentration was achieved.Body movement was defined as the directional movement in head or four extremities during gastroscopy.The target plasma concentration of propofol was determined by up-and-down sequential trial.Each time the plasma concentration of propofol increased/decreased by 0.5 μg/ml in the next patient depending on whether or not body movement developed.The EC50 and 95 ％ confidence interval of propofol inhibiting gastroscopy-evoked body movement were determined using Probit analysis.Results The EC50 (95 ％ confidence interval) of propofol was 4.2(3.8-4.5),4.1(3.7-4.4) and 2.4(1.8-2.7) μg/ml in Ⅰ,Ⅱ and Ⅲ groups,respectively.There was no significant difference in the EC50 of propofol between group Ⅱ and group Ⅰ.The EC50 of propofol was significantly lower in group Ⅲ than in Ⅰ and Ⅱ groups.Conclusion Age affects propofol-induced analgesia in patients with visceral pain,and the potency of propofol inhibiting visceral pain during gastroscopy in the elderly patients is significantly enhanced as compared with that in the young and middle-aged patients.
ABSTRACT
Objective Replacement of dexmedetomidine with propofol for maintaining the anes-thesia in elderly patients undergoing laparoscopic cholecystectomy.Methods Ninety patients,over 70 years old,undergoing laparoscopic cholecystectomy were randomly divided into 2 groups,propofol combined with remifentanil (group A),dexmedetomidine combined with remifentanil (group B),45 patients in each group.Group A was not treated with any preoperative medication,while group B was treated with loading dose of 0.5 μg/kg dexmedetomidine intravenously completed within 10 minutes. Induction methods were same in both groups,3 # or 4 # laryngeal mask were inserted after induction in both groups.Maintenance of anesthesia in group A treated with propofol 2.0-3.0 μg/ml + 4.5-5.5 ng/ml TCI;Maintenance of anesthesia in group B treated with dexmedetomidine 0.25 μg·kg-1·h-1 +remifentanil 4.5-5.5 ng/ml (TCI).HR,SBP,DBP,BIS were recorded at inserting the LMA (T1 ), beginning of the surgery (T2 ),dissociate the cholecyst (T3 ),withdrawal of the laparoscope (T4 ), extubate the LMA (T5 ).Postoperative recovery time,Steward awakening score and modified OAA/S score at extubation time were recorded.Results No significant difference was found between BIS val-ue of two groups at different time point.Compared with group A,HR at T1-T5 in group B were sig-nificantly lower,SBP,DBP were significantly decreased (P <0.05).There was no significant differ-ence between Steward awakening score and modified OAA/S score at recovery and extubation time in two groups.Conclusion Dexmedetomidine replacing propofol can be safely used in laparoscopic chole-cystectomy with less hemodynamic changes during maintenance of anesthesia in elderly patients.
ABSTRACT
Objective To evaluate the effects of different doses of fentanyl on the median effective target plasma concentration (EC50) of propofol inhibiting body movement evoked by gastroscopy in the elderly patients.Methods Ninety patients of both sexes,aged 75-89 yr,with a body mass index of 19-25 kg/m2,of ASA physical status Ⅱ or Ⅲ,scheduled for elective gastroscopy,were randomly divided into 3 groups (n =30 each):control group (group C) and different doses of fentanyl groups (F0.5 and F1.0 groups).Fentanyl 0.5 and 1.0 μg/kg were injected intravenously in F0.5 and F1.0 groups,respectively.Propofol was then administered by target-controlled infusion.The initial target plasma concentrations (Cps) of propofol were 2.0,1.5 and 1.0 μg/ml in C,F0.5 and F1.0 groups,respectively.Gastroscopy was performed after the target effect-site and plasma concentrations were balanced.Body movement was defined as movement in head or four extremities during gastroscopy.The target Cp of propofol was determined by up-and-down sequential trial.Each time the Cp increased/decreased by 0.5 μg/ml in the next patient depending on whether or not body movement developed.The EC50 and 95 ％ confidence interval (CI) of propofol inhibiting gastroscopy-evoked body movement were determined using Probit analysis.Results The EC50 (95 ％ CI) of propofol was 2.24 ng/ml (1.67-2.47 ng/ml) in group C,1.79 (1.55-1.95) μg/ml in group F0.5,and 1.13 (1.08-1.62) μg/ml in group F1.0.There was no significant difference in the EC50 of propofol between F0.5 and C groups.The EC50 of propofol was significantly lower in F1.0 group than in C and F0.5 groups.Conclusion When combined with propofol,fentanyl 1.0 μg/kg is recommended for gastroscopy in the elderly patients.
ABSTRACT
ObjectiveTo explore the efficacy of sevoflurane or propofol combined with remifentanil during the maintenance of general anesthesia in thyroid gland surgery.MethodsSixty patients underwent thyroid gland surgery were randomly divided into tow groups.Once the larynx mask was intubated, anesthesia was maintained with propofol(the effect site concentration was 2.5 ～3.5mg/L) and remifentanil(the effect site concentration was 4.5 ～5.5μg/L) by TCI technique in group P,but with sevoflurane(2％～4％) and remfentanil(the effect site concentration was 2.5 ～4.0g/L)in group S.The depth of anesthesia was measured by the A-line TM AEP Monitor which expressed as A-Line ARX Index TM(AAI).All patients' SBP,DBP and HR were recorded at eight time points: before induction time(T0) ,after induction but before larynx mask intubation time(T1) ,intubate larynx mask time(T2) ,cut skin time (T3), separate thyroid gland time (T4), cut thyroid gland time (T5), remove larynx mask time (T6) ,leave the operation room time(T7).The emergency time,the conscious of the patients after anesthesia and the side effects were also recorded.ResultsThere were no significant differences between the groups with respect to age,gender,weight,the duration of operation,the emergency time and the conscious of the patients after anesthesia.SBP,DBP,HR of the patients in both groups showed no significant difference at T0,T1 ,T2, T3 (all P ＞ 0.05), but had significant difference at T4,T5,T6, T7 (all P ＜ 0.05).Compare with group P,the incidentce of restlessness, dizziness, drowsiness, rigor and pain was significantly lower in group S(all P ＜0.05).The incidentce of nausea,vomit and aspiration did not appear in both groups.ConclusionBoth groups showed good anesthesia effects and the patients also emerged from anesthesia quickly.But the anesthesia maintained with sevoflurane and remifentanil could bring more stable hemodynamics and lower incidence rate of the side effects.