Objective:To evaluate the dose-response relationship of alfentanil in combination with midazolam-etomidate inhibiting cardiovascular responses to laryngeal mask airway implantation in elderly patients.Methods:American Society of Anesthesiologists Physical Status Ⅰ or Ⅱ patients of either sex, aged 65-85 yr, with body mass index of 20-30 kg/m 2, undergoing elective operation under general anesthesia, were enrolled in this study.Midazolam 0.025 mg/kg was intravenously injected for adequate sedation, 5 min later mean arterial pressure and heart rate were recorded for 3 consecutive times at 3-min interval, the mean value was collected and considered as the baseline value.Etomidate 0.2 mg/kg was intravenously injected, and alfentanil and rocuronium 0.6 mg/kg were intravenously injected when bispectral index value < 60.A laryngeal mask airway was inserted at 1.4 min after intravenous injection of alfentanil, and mechanical ventilation was performed.The dose of alfentanil was determined by the Dixon′s up-and-down method.The initial dose of alfentanil was set at 6.83 μg/kg.The dose of alfentanil in the next patient was determined according to the development of cardiovascular response to laryngeal mask airway placement.If the cardiovascular response to laryngeal mask airway placement occurred, the dose was increased for the next patient, and if cardiovascular response to laryngeal mask airway placement did not occur, the dose was decreased, and the ratio between the two successive doses was 1.0∶1.1.The cardiovascular response to laryngeal mask airway placement was defined as increase in maximum mean arterial pressure or maximum heart rate by≥20% of baseline values within 2 min after laryngeal mask airway placement.The median effective dose (ED 50), 95% effective dose (ED 95) and 95% confidence interval (95% CI) of alfentanil inhibiting cardiovascular responses to laryngeal mask airway placement in elderly patients were calculated by the Probit method. Results:When combined with midazolam and etomidate, the ED 50 (95% CI) of alfentanil inhibiting the cardiovascular responses to laryngeal mask airway placement in elderly patients were 5.605 (5.036-6.082) μg/kg, and the ED 95 (95% CI) were 6.625 (6.125-9.763) μg/kg. Conclusions:When combined with midazolam and etomidate, the ED 50 and ED 95 of alfentanil inhibiting the cardiovascular responses to laryngeal mask airway placement are 5.605 and 6.625 μg/kg, respectively, in elderly patients.

Objective:To determine the median effective dose (ED 50) of ciprofol inhibiting responses to insertion of laryngeal mask airway in the patients when combined with alfentanil. Methods:American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ patients of either sex, aged 40-64 yr, with body mass index of 20-30 kg/m 2, undergoing elective general anesthesia, were enrolled. Midazolam 0.025 mg/kg was intravenously injected for anesthesia induction, the baseline mean arterial pressure and heart rate were recorded 5 min later, and the average value of three times was considered as the baseline value. Ciprofol and alfentanil 10 μg/kg were intravenously injected in sequence, rocuronium 0.6 mg/kg was intravenously injected when BIS value < 60, 2 min later a laryngeal mask airway was placed, and mechanical ventilation was performed. Positive response was defined as increase in the maximum mean arterial blood pressure or heart rate more than or equal to 20% of the baseline value within 3 min after placement of the laryngeal mask airway or as the occurrence of body movement, bucking, frowning, mouth and face twitching, tearing, laryngospasm or the BIS value failing to drop below 60. The study was performed by the Dixon′s up-and-down method. The initial dose of ciprofol was 0.4 mg/kg, and the ratio between the two successive doses was 1.1. If a positive response occurred, the dose was increased in the next patient, otherwise the dose was reduced. The ED 50 and 95% confidence interval of ciprofol inhibiting responses to insertion of laryngeal mask airway were calculated by the probit method. Results:The ED 50(95% confidence interval) of ciprofol inhibiting responses to insertion of laryngeal mask airway was 0.291(0.231-0.318) mg/kg when combined with alfentanil 10 μg/kg. Conclusions:The ED 50 of ciprofol inhibiting responses to insertion of laryngeal mask airway is 0.291 mg/kg in the patients when combined with alfentanil 10 μg/kg.

Objective:To investigate the dose-effect relationship of alfentanil inhibiting cardiovascular responses to tracheal intubation when combined with midazolam and etomidate.Methods:American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ patients of either sex, aged 18-64 yr, with body mass index<32 kg/m 2, undergoing elective operation under general anesthesia with endotracheal intubation, were enrolled in this study.Midazolam 0.025 mg/kg was intravenously injected for adequate sedation, and 5 min later mean arterial pressure and heart rate were recorded for 3 consecutive times at an interval of 3 min, and the mean value was calculated and served as the baseline value.Etomidate 0.3 mg/kg was intravenously injected, and alfentanil and rocuronium 0.6 mg/kg were intravenously injected when bispectral index value < 60, and then 1.4 min later tracheal intubation was performed.The dose of alfentanil was determined by the Dixon′s up-and-down method.The initial dose of alfentanil was set at 20 μg/kg.The dose of alfentanil in the next patient was determined according to the development of cardiovascular responses to tracheal intubation, and the ratio between the two successive doses was 1.0∶1.1.The cardiovascular response was defined as as positive when the maximum value of mean arterial pressure or heart rate increased by ≥20% of the baseline value within 2 min after endotracheal intubation.Probit method was used to determine the ED 50, ED 95 and 95% confidence interval of alfentanil inhibiting cardiovascular responses to tracheal intubation. Results:When combined with midazolam and etomidate, the ED 50 (95% confidence interval) of alfentanil inhibiting cardiovascular responses to tracheal intubation was 21.343 (19.105-24.516) μg/kg, and the ED 95 (95% confidence interval) was 25.043 (22.983-48.983) μg/kg. Conclusions:When combined with midazolam and etomidate, the ED 50 and ED 95 of alfentanil inhibiting cardiovascular responses to tracheal intubation are 21.343 and 25.043 μg/kg, respectively.

Objective To observe the effect of ultrasound-guided iliopsoas plane block(IPB)on the quality of postoperative recovery in patients undergoing hip arthroplasty.Methods Sixty patients who underwent hip arthroplasty were selected,37 males and 23 females,aged 40-79 years,BMI 18-30 kg/m2,ASA physical status Ⅰ-Ⅲ.The patients were divided into two groups by random number table method:the iliopsoas plane block group(group IPB)and the femoral nerve block(FNB)group(group FNB),30 pa-tients in each group.Before anesthesia induction,IPB was performed with 0.5%ropivacaine 10 ml and lat-eral femoral cutaneous nerve block was performed with 0.5%ropivacaine 5 ml in group IPB.And FNB was performed with 0.5%ropivacaine 10 ml and lateral femoral cutaneous nerve block was performed with 0.5%ropivacaine 5 ml in group FNB.The dosages of propofol,remifentanil,and cis-atracurium during operation were recorded.The quality of recovery-15(QoR-15)scale was evaluated preoperatively and postoperatively 1 day,2 and 3 days.The max VAS(VASmax)pain score and manual muscle test(MMT)score of quadri-ceps muscle were recorded 12,24,and 48 hours after surgery.The time of getting out of bed for the first time,opioid dosage,and patient satisfaction were recorded.The incidence of nerve injury,vascular injury,puncture site infection,and local anesthetic poisoning were recorded.The postoperative complications of diz-ziness,nausea and vomiting,deep vein thromboses,and elirium were also recorded.Results There was no significant difference in the dosage of propofol,remifentanil,and cis-atracurium between the two groups.Compared with group FNB,the QoR-15 scale score in group IPB was significantly higher 1 day,2 and 3 days after operation(P＜0.05).Compared with group FNB,the MMT scores of quadriceps muscle was sig-nificantly higher in group IPB 12 and 24 hours after surgery(P＜0.05),and the first time of getting out of bed was shortened in group IPB(P＜0.05).However,there were no significant differences in the VASmax pain score,MMT score of quadriceps muscle 48 hours after surgery,opioid dosage,and patient satisfaction between the two groups.No nerve block related complications were found in both groups.There were no sig-nificant differences in postoperative complications between the two groups.Conclusion The iliopsoas plane block can improve the quality of postoperative recovery and accelerate the recovery of patients with hip re-placement,and the effect is better than that of femoral nerve block.