Objective To determine the ED50 of remifentanil needed for tracheal intubation without neuromuscular relaxant in children when combined with sevoflurane inhalation.Methods Twenty-five ASA Ⅰ or Ⅱ children of both sexes,aged 4-9 yr,scheduled for elective surgery under general anesthesia were enrolled in this study.Anesthesia was induced with inhalation of 5% sevoflurane in 100% oxygen and PETCOM2was maintained at 30-35 mm Hg.Remifentanil was injected intravenously over 30 s after 3 min inhalation of sevoflurane.Tracheal intubation was performed 90 s after the completion of remifentanil injection.The experiment was performed using the modified Dixon's up-and-down method.The initial dose of remifentanil was set at 1.2 μg/kg and the ratio between two successive doses was 1.2.Intubation conditions were assessed by a blinded observer using Viby-Mogensen scale.If the conditions were not good,roenronium 0.3 mg/kg was then injected intravenously to facilitate intubation.The ED50 of remifentanil and 95% confidence interval (95% CI) were calculated.Results The ED50 of remifentanil combined with inhalation of scvoflurane required for successful intubation was 0.68 μg/kg in the absence of neuromuscular relaxant,and 95% CI was 0.65-0.71 μg/kg.Conclusion The ED50 of remifentanil required for tracheal intubatiun without neuromuscular relaxant drug is 0.68 μg/kg (95% CI 0.65-0.71 μg/kg) when combined with 5% sevoflurane inhalation in children.

Objective To evaluate the reliability of Amsterdam Preoperative Anxiety and Information Scale (APAIS) score in evaluating the preoperative anxiety of Chinese people.Methods One hundred sixty Chinese patients of both sexes, aged 18-60 yr, of American Society of Anesthesiologists physical status Ⅰ-Ⅲ, scheduled for elective surgery, were enrolled.Preoperative anxiety of the patients was assessed with APAIS score and Spielberger's State-Anxiety Inventory (S-AI) questionnaire during the preoperative interview.Cronbach's alpha of total anxiety and need for information scores was calculated.Four thresholds of total anxiety score in identifying preoperative severe anxiety was set as 10, 11, 12 and 13.S-AI questionnaire was considered as the standard, and the correlation between total anxiety score and S-AI questionaire was tested.Results The Cronbach's alpha of total anxiety and need for information scores was 0.84 and 0.71, respectively.When the threshold of total anxiety score in identifying preoperative severe anxiety was 12, the total anxiety score was highly correlated with S-AI questionnaire, the Kappa value was 0.62, 95％ confidence interval was 0.46-0.78, the sensitivity was 0.71, the specificity was 0.90, and the positive predictive value was 0.78.Conclusion APAIS score can be used to assess the preoperative anxiety of Chinese people.

Objective To evaluate the efficacy of small dose dexmedetomidine mixed with mor-phine for patient-controlled intravenous analgesia ( PCIA) in patients with cancer pain complicated with opi-oid tolerance-oral difficulty. Methods Sixty patients with moderate to severe cancer pain complicated with opioid tolerance-oral difficulty were divided into morphine group ( M group, n=30) and dexmedetomidine plus morphine group ( DM group, n=30) using a random number table method. Morphine 200 mg was di-luted to 200 ml in normal saline in group M. Morphine 200 mg plus dexmedetomidine 600μg was diluted to 200 ml in normal saline in group DM. PCIA was performed ( background infusion 0. 5-1. 0 ml∕h, bolus dose 0. 5-1. 0 ml, lockout interval 15 min) on the basis of the original narcotic analgesics in two groups. The target of analgesia was numeric rating scale score≤3, the number of pain occurred per day <3 times, and pain could be rapidly relieved by pressing PCA pump. When the target of analgesia was not achieved or adverse reactions occurred without opioid tolerance within 72 h, minimally invasive analgesia was performed according to condition. Numeric rating scale score, effective analgesia, minimally invasive analgesia, con-sumption of opioids ( the consumption of opioids was converted into the amount of morphine taken orally) , patient′s satisfaction score, quality of life score and drug-related adverse reactions were recorded before PCIA and at 3 days and 1 month of PCIA. Results Compared with group M, the consumption of opioids was significantly decreased at 3 days and 1 month of PCIA, and no significant change was found in the rate of effective analgesia, rate of minimally invasive analgesia, quality of life score, satisfaction score or inci-dence of adverse reactions in group DM ( P>0. 05) . Hyperalgesia, respiratory depression or marked change in blood pressure was not found in two groups. Compared with the baseline before PCIA, the incidence of somnolence at 3 days of PCIA and incidence of constipation at 1 month of PCIA were increased in group M, and the incidence of somnolence was increased at 3 days and 1 month of PCIA in group DM (P<0. 05). Conclusion PCIA with small dose dexmedetomidine mixed with morphine can reduce the consumption of opioids and exert safe and effective analgesic efficacy when used for the patients with cancer pain complicat-ed with opioid tolerance-oral difficulty.