Objective:To investigate the effect of acute hypervolemic hemodilution (AHH) with 6% hydroxyethyl starch 130/0.4 on pharmacodynamics of propofol during successful laryngeal mask airway (LMA) implantation.Methods:American Society of Anesthesiology physical status Ⅰ or Ⅱ patients, aged 30-60 yr, with body mass index of 18.5-25.0 kg/m 2, undergoing elective extensive total hysterectomy under general anesthesia, were divided into 2 groups: AHH group (group A) and control group (group C). In group A, 6% hydroxyethyl starch 130/0.4 was infused at a rate of 20 ml/min for AHH, and the target hematocrit was 30%.In group C, lactated Ringer′s solution was infused according to the " 4-2-1" rule to supplement physiological requirements, and anesthesia induction was performed after 10 min of stabilization.Sufentanil was administered by target-controlled infusion using Bovil pharmacokinetic model with effect-site concentration (Ce) of 0.25 ng/ml, 3 min later propofol was given by target-controlled infusion using Schnider model.The Ce of propofol in the first patient was set at 5.0 μg/ml.Each time the concentration of propofol was increased/decreased by 0.5 μg/ml according to the sequential method.LMA was inserted following 1 min equilibration between plasma concentration and Ce of propofol.The trial was terminated when 8 consecutive inflection points of failed/successful LMA insertion occurred.The EC 5, EC 50, EC 95 and 95% confidence interval (95% CI) of propofol were calculated by probit regression analysis. Results:In group A, the EC 5 (95% CI), EC 50 (95% CI) and EC 95 (95% CI) of propofol when LMA was successfully placed were 4.237 (3.090-4.514) μg/ml, 4.802 (4.500-5.078) μg/ml and 5.443 (5.125-7.304) μg/ml, respectively.In group C, the EC 5 (95% CI), EC 50 (95% CI) and EC 95 (95% CI) of propofol when LMA was successfully placed were 2.408 (1.190-2.756) μg/ml, 3.120 (2.690-3.472) μg/ml and 4.042 (3.582-7.431) μg/ml, respectively.There was significant difference in EC 5, EC 50 and EC 95 between the two groups ( P<0.01). Conclusion:AHH with 6% hydroxyethyl starch 130/0.4 can decrease the efficacy of propofol when LMA is successfully implanted.

Objective:To evaluate the effect of esketamine combined with ultrasound-guided dorsal penile nerve block (DPNB) on negative postoperative behavioral changes (NPOBCs) in pediatric patients undergoing circumcision under general anesthesia.Methods:One-hundred and ninety-five pediatric patients, aged 4-8 yr, with body mass index of 10-35 kg, of American Society of Anesthesiologists Physical Status classificationⅠ or Ⅱ, undergoing elective circumcision under general anesthesia, were selected and divided into 3 groups ( n=65 each) using a random number table method: esketamine group (group E), DPNB group (group D) and esketamine combined with DPNB group (group ED). Propofol 1.5 mg/kg was intravenously injected, and the patients were admitted to the operating room after consciousness disappeared in the 3 groups. Esketamine 0.5 mg/kg was intravenously injected in E and ED groups, and the equal volume of normal saline was given in group D. D and ED groups underwent bilateral DPNB with 0.25 % ropivacaine 0.15 ml/kg under ultrasound guidance, with the maximum total amount of the drug not exceeding 10 ml. Fentanyl 1.0 μg/kg and propofol 2.0 mg/kg were intravenously injected prior to the skin incision in the three groups. If intraoperative body movement occurred, propofol 10 mg was added, which could be repeated. The occurrence of intraoperative body movement, respiratory depression and amount of propofol added was recorded. When postoperative pain (FLACC score >4) occurred, flurbiprofen 1 mg/kg was intravenously injected for analgesia, and the usage of flurbiprofen was recorded. When emergence agitation(PEAD score>10) occurred, propofol 1 mg/kg was intravenously injected for sedation, and the occurrence of emergence agitation was recorded. Parents were followed up by telephone at 1, 7 and 30 days postoperatively to assess the occurrence of NPOBCs using the PHBQ scale. Results:Fifty-six patients in group E and 59 patients in D and ED groups finally completed the study.Compared with group E, the incidence of intraoperative body movement was significantly decreased, the amount of additional propofol was reduced, the emergence agitation score, incidence of emergence agitation and severe agitation and usage rate of postoperative flurbiprofen were decreased, and the incidence of separation anxiety at 7 and 30 days postoperatively was decreased in D and ED groups, and the incidence of intraoperative respiratory depression was significantly decreased, and the incidence of NPOBCs at 7 and 30 days postoperatively was decreased in group ED ( P<0.05). Compared with group D, the incidence of intraoperative respiratory depression was significantly decreased, the amount of additional propofol was decreased, the usage rate of postoperative flurbiprofen and incidence of sleep anxiety at 1 day postoperatively were decreased ( P<0.05), and no significant change was found in the incidence of NPOBCs at each time point after operation in group ED ( P>0.05). Conclusions:Esketamine combined with ultrasound-guided DPNB can reduce the occurrence of NPOBCs in pediatric patients undergoing circumcision under general anesthesia.