Effect of intravenous lidocaine on the median effective concentration of propofol in suppressing body movement during cervical dilation in induced abortion
Objective To investigate the effect of intravenous lidocaine on the median effect con-centration(EC50)for the suppression of body movement during cervical dilation in artificial abortion proce-dures under propofol target-controlled infusion(TCI)using the Schnider model.Methods Forty-six patients were those seeking their initial artificial abortion,aged 18-35 years,with a gestational period of 6-9 weeks,BMI 18-25 kg/m2,and ASA physical status Ⅰ or Ⅱ.Participants were randomly divided into two groups:lidocaine(group L,n=25)and saline(group C,n=21),determined by a sequence crea-ted by a computer.Group L was administered lidocaine intravenously at a dosage of 1 mg/kg,whereas group C was given a similar amount of saline.The Schnider TCI model was used to administer propofol,starting with an effect-site concentration of 4.0 μg/ml.According to the Dixon sequential method,a body movement reaction of grade 2 or higher during cervical dilation was classified as a positive response,necessitating an increase in the concentration gradient by one level for the subsequent case.Conversely,if the reaction was below grade 2,the concentration gradient should be decreased by one level for the next case.The adjacent concentration gradients were 0.5 μg/ml.The study would be terminated if there were 7 consecutive positive responses.The EC50,the 95％effective concentration(EC95),and the corresponding 95％confidence in-terval(CI)for inhibiting body movement by propofol during cervical dilation in the two groups were deter-mined using probit regression analysis.Patient data including time to loss of consciousness,recovery time,the amount of propofol used for the procedure,cervical dilation effect,propofol injection pain,and VAS pain score at 15 minutes post-operation were recorded.Additionally,note the occurrence of hypoxemia and perioperative hypotension,as well as postoperative adverse reactions such as nausea,vomiting,and dizziness were recorded.Results In group L,the EC50 and EC95 of propofol in suppressing body movement during cervical dilation was 3.82 μg/ml(95％CI 3.59-4.03 μg/ml)and 4.25 μg/ml(95％CI 4.04-5.10 μg/ml).In group C,the EC50 and EC95 of propofol in suppressing body movement during cervical di-lation were 4.09 μg/ml(95％CI 3.71-4.41 μg/ml)and 4.65 μg/ml(95％CI 4.36-6.48 μg/ml).Compared with group C,group L exhibited a notable decrease in the EC50 of propofol,along with a signi-ficant reduction in propofol dosage,the total effective rate of cervical dilatation was also significantly im-proved,while the incidence of propofol injection pain and hypoxemia was significantly decreased(P＜0.05).Conclusion Administering intravenous lidocaine at a dosage of 1 mg/kg can reduce the EC50 of propofol required to suppress body movement during cervical dilation in induced abortion under the Schnider TCI model,which decreases the amount of propofol needed,reduces the incidence of injection pain,im-proves the effect of cervical dilation,and results in fewer adverse reactions.
万方数据
维普
