改良序贯法测定小儿核磁共振成像检查中右美托咪定滴鼻镇静的有效剂量

摘要

目的：用改良序贯法测定小儿核磁共振成像（MRI）检查中右美托咪定滴鼻镇静的半数有效量( ED50)和95%有效量( ED95)。方法随机选择美国麻醉医师协会( ASA )Ⅰ~Ⅱ级、接受MRI检查需镇静的1~6岁患儿30例，MRI检查前30~45 min经鼻滴入右美托咪定，剂量根据改良序贯法确定，根据上1例患儿检查中的镇静效果，下1例患儿增加或减少0.25μg/kg。用回归分析法计算出右美托咪定有效镇静的 ED50，ED95及相应的95%可信区间（95% CI）。结果右美托咪定滴鼻镇静的 ED50为2.15μg/kg，95% CI为1.93~2.32μg/kg；相应的 ED95为2.60μg/kg，95% CI为2.39~3.68μg/kg。结论小儿MRI检查中右美托咪定滴鼻简便安全，依从性好，不良反应少，改良序贯法测定其镇静的 ED50和 ED95分别为2.15μg/kg和2.60μg/kg。%Objective To determine the ED50 and ED95 of intranasal dexmedetomidine sedation for MRI scanning with the modified Dixon's up-and-down method in children. Methods 30 Cases of ASA physical status Ⅰor Ⅱchildren,aged 1-6 years old,sched-uled for MRI scanning were randomly enrolled in this study. Dexmedetomidine was dropped into each nostril at the time of 30 to 45 minutes before MRI scanning,and the dose of intranasal dexmedetomidine was determined using the modified Dixon's up-and-down method by the sedation effect of the previous children,in an increment or decrement of 0. 25 μg/kg. Probit analysis was used for cal-culating ED50,ED95 and 95% confidence interval ( CI) of intranasal dexmedetomidine sedation. Results The ED50 of intranasal dexmedetomidine sedation was 2. 15 μg/kg (95% CI was 1. 93-2. 32 μg/kg),and ED95 intranasal dexmedetomidine sedation was 2. 60 μg/kg(95% CI was 2. 39-3. 68 μg/kg). Conclusion The intranasal route to dexmedetomidine delivery is a simple security,good patient compliance and fewer side effects for MRI scanning in children. The ED50 and ED95 of intranasal dexmedetomidine sedation are 2. 15 μg/kg and 2. 60 μg/kg respectively with the modified Dixon's up-and-down method.