复合丙泊酚时阿芬太尼抑制胃镜置入反应的半数有效剂量

Median effective dose of alfentanil blunting responses to gastroscopy when combined with propofol

目的 探讨复合丙泊酚时阿芬太尼抑制胃镜置入反应的半数有效剂量(ED_(50))。方法选择择期行胃镜检查患者23例,男11例,女12例,年龄18~64岁,BMI 18~24 kg/m^(2),ASAⅠ或Ⅱ级。麻醉诱导时静脉注射阿芬太尼(30 s内推注完毕),随后给予丙泊酚血浆靶控输注,靶控浓度为3μg/ml,待改良警觉镇静评分(MOAA/S)评分为0分时置入胃镜。依据Dixon序贯法确定阿芬太尼剂量(初始剂量为4.5μg/kg),如出现胃镜置入阳性反应,则下一位患者增加剂量至高一级,否则降低剂量至低一级,剂量梯度为0.5μg/kg。胃镜置入阳性反应标准:胃镜置入时或1 min内患者出现呛咳、恶心和(或)发生体动反应。研究过程中出现7次折返则停止试验。计算复合丙泊酚时阿芬太尼抑制胃镜置入反应的ED_(50)、95%有效剂量(ED_(95))及95%可信区间(CI)。结果 复合丙泊酚时单次静脉推注阿芬太尼抑制胃镜检查患者置入反应的ED_(50)为4.70μg/kg(95%CI 3.92~5.79μg/kg),ED_(95)为5.87μg/kg(95%CI 5.23~16.94μg/kg)。结论 复合丙泊酚时阿芬太尼抑制胃镜检查患者置入反应的ED_(50)为4.70μg/kg。

Objective To determine the median effective dose(ED_(50)) of alfentanil inhibiting responses to gastroscopy combined with propofol infusion.Methods Twenty-three patients undergoing gastroscopy,11 males and 12 females,aged 18-64 years,BMI 18-24 kg/m^(2),ASA physical status Ⅰ or Ⅱ,were enrolled.Patients received intravenous infusion of alfentanil within 30 seconds,and subsequently received propofol plasma target-controlled infusion with a target concentration of 3 μg/ml.Gastroscopy was performed when the level of modified observer’s assessment of alertness and sedation(MOAA/S) was 0.The dose of alfentanil was determined using modified Dixon’s up-and-down sequential method,and the initial dose was 4.5 μg/kg.When the insertion response was positive,the concentration of alfentanil increased by 0.5 μg/kg in the next patient.Otherwise,the concentration decreased by 0.5 μg/kg in the next patient.The insertion response of gastroscopy was defined as choking cough,nausea,and/or body movement when inserting the gastroscopy into pharyngeal cavity or within 1 minute.The test was completed after 7 independent cross-over pairs were observed.The ED_(50),95% effective does(ED_(95)) and 95% confidence interval(CI) of alfentanil inhibiting responses to gastroscopy were calculated.Results When intravenous infusion combined with propofol,the ED_(50) of alfentanil inhibiting responses to gastroscopy insertion was 4.70 μg/kg(95% CI 3.92-5.79 μg/kg),and the ED_(95) was 5.87 μg/kg(95% CI 5.23-16.94 μg/kg).ConclusionThe ED_(50) of alfentanil inhibiting responses to gastroscopic insertion was 4.70 μg/kg when intravenously infused combined with propofol.