右美托咪定预防门诊七氟醚吸入麻醉患儿苏醒期躁动的适宜剂量

Optimum dose of dexmedetomidine for prevention of emergence agitation after sevoflurane anesthesia in children undergoing ambulatory surgery

目的:探讨右美托咪定预防门诊七氟醚吸入麻醉患儿苏醒期躁动的适宜剂量。方法:择期拟在门诊吸入全麻下行龋齿治疗的患儿22例,ASA分级Ⅰ或Ⅱ级,年龄2~7岁,性别不限。面罩吸入8%七氟醚进行麻醉诱导,置入喉罩后静脉输注右美托咪定10 min预防患儿苏醒期躁动,采用序贯法确定右美托咪定输注剂量。第1例患儿输注右美托咪定的剂量为0.5μg/kg,相邻剂量差值为0.1μg/kg。2%~4%七氟醚吸入维持麻醉,术中保持自主呼吸,术毕停用七氟醚,待患儿苏醒。以儿童麻醉苏醒期躁动量表(pediatric anesthesia emergence delirium scale,PAED)评分作为判断患儿发生苏醒期躁动的标准,分别于术后5、10、15、20、25、30 min记录PAED评分,取评分的最高值,评分≥10分视为苏醒期躁动。分别于苏醒后即刻(T0)、10 min(T1)、20 min(T2)记录改良东安大略儿童医院疼痛量表(modified children’s hospital of eastern ontario pain scale,m-CHEOPS)评分评价疼痛程度。计算右美托咪定预防50%、95%患儿门诊七氟醚吸入麻醉后苏醒期躁动的剂量(ED50、ED95)及其95%可信区间。结果:与无苏醒期躁动组比较,发生苏醒期躁动组T0时m-CHEOPS评分增加(P<0.05);两组T1~2时m-CHEOPS评分无统计学差异(P>0.05);2组患儿的年龄、体质量、身长、手术时间、苏醒时间无统计学差异(P>0.05)。右美托咪定预防门诊七氟醚吸入麻醉患儿苏醒期躁动的ED50及其95%可信区间为0.58(0.43~0.73)μg/kg,ED95及其95%CI为0.78(0.67~2.27)μg/kg。结论:右美托咪定预防门诊七氟醚吸入麻醉患儿苏醒期躁动的ED50为0.58μg/kg,ED95为0.78μg/kg。

Objective：To determine the optimum dose of dexmedetomidine for prevention of emergence agitation after sevoflurane anes- thesia in children undergoing ambulatory surgery. Methods ：Twenty-two ASA Ⅰ or Ⅱ children of both sexes aged 2-7 years undergo- ing elective dental repair under sevoflurane anesthesia were studied. Laryngeal mask airway （LMA） was inserted after induction of anesthesia with inhalation of 8% sevoflurane by mask. Dexmedetomidine was intravenous infused for 10 minutes to prevent emergence agitation after LMA insertion. The dose of dexmedetomidine was determined by using Dixon＇s up2and-down method（increment or decrement of 0.1 μg/kg）. The initial dose of dexmedetomidine was 0.5 μg/kg. Anesthesia was maintained with 2%--4% sevoflurane and spontaneous breathing was maintained throughout the surgery. Sevoflurane inhalation was terminated at the end of surgery. The Pe-diatric Anesthesia Emergence Delirium Scale（PAED） was used to assess emergence agitation. The PAED score was recorded every 5 minutes within 30 minutes after surgery. And the max score more than ten was considered emergence agitation. The modified Children＇s Hospital of Eastern Ontario Pain Scale （m-CHEOPS） score was recorded immediately after recovery （To） ,and 10 and 20 minutes （T1,T2） after recovery for evaluat- ing the pain degree. The ED50,ED95 and 95% confidence inter-val（Cl） of dexmedetomidine for prevention of emergence agitation were calculated. Results：The m-CHEOPS score was significantly increased at To in emergence agitation group than in no emergence agitation group（P〈0.05）. There was no .significant difference be- tween the two groups in m-CHEOPS score at T1-2（P〉0.05）. There was no significant difference between the two groups in terms of age, weight, height, operation time and emergence time （P〉0.05）. The ED50 of dexmedetomidine for prevention of emergence agita- tion after sevoflurane anesthesia in children undergoing ambulatory surgery was 0.58 μg/kg（95%CI=0.43 to 0.73 μg/kg）. ED95 was 0.78 vg/kg（95%CI=0.67 to 2.27 μg/kg）. Conclusion：The ED50 and ED95 of dexmedetomidine for prevention of emergence agitation after sevoflurane anesthesia in children undergoing ambulatory surgery are 0.58 μg/kg and 0.78 μg/kg respectively.