右美托咪啶复合七氟醚对儿童脊柱侧弯矫形术唤醒试验的影响

目的：评估使用0.4 μg/(kg·h)剂量的右美托咪啶复合七氟醚麻醉对儿童脊柱侧弯矫形术唤醒试验的影响。方法： 采用前瞻性、双盲、随机对照研究，选择60例符合入选标准拟在全身麻醉下行脊柱侧弯后路矫形术且术中需作唤醒试验的儿童患者为观察对象，美国麻醉医师协会（American Society of Anesthesiologist, ASA) 分级Ⅰ～Ⅱ，年龄5～16岁。将患者随机分为试验组（右美托咪啶组，RD组，n=30）和对照组（R组，n=30）,两组均用咪达唑仑、丙泊酚、舒芬太尼和顺阿曲库铵麻醉诱导，采用吸入七氟醚和持续泵注瑞芬太尼维持麻醉。在气管导管置入后，试验组以0.4 μg/(kg·h)的速度持续静脉输注右美托咪啶，对照组以同样的速度输注等量生理盐水。在实施唤醒试验前的手术期间，维持脑电双频指数（bispectral index，BIS）在40~60，平均动脉压（mean arterial pressure, MAP)≥ 60 mmHg；维持中心静脉压（central venous pressure, CVP)在手术前水平，上下不超过2 mmH2O。记录两组在入室第10分时、唤醒试验开始（停药即刻）时至唤醒成功期间的每5 min有创收缩压（systolic blood pressure, SBP）、舒张压（diastolic blood pressure, DBP）、平均动脉压、心率(heart rate,HR)、BIS值以及唤醒试验的历时时间、唤醒质量、镇静评分及术中使用麻黄碱和阿托品的总量，记录术中知晓情况。结果： 试验组的入室HR和MAP与唤醒时HR和MAP比较，差异无统计学意义（t=0.974,P=0.340；t = -1.449,P=0.161），而对照组的入室HR和MAP与唤醒时HR和MAP比较，差异有统计学意义（t=-2.106，P=0.044；t=-2.352，P=0.026）。唤醒试验期间每5 min两组心率比较，试验组在各时点明显低于对照组，差异有统计学意义（P＜ 0.05）；在唤醒试验中的镇静评分和停药至成功唤醒时间两组比较，差异无统计学意义（t=1.986，P=0.052；t=0.392，P=0.697），唤醒质量评分试验组明显优于对照组（R组），差异有统计学意义（t=-2.098，P=0.041）。术后随访，试验组无术中知晓病例，对照组有4例发生术中知晓。 结论： 使用0.4 μg/(kg·h)剂量的右美托咪啶复合七氟醚麻醉用于儿童脊柱侧弯矫形术，能减轻唤醒试验期间血流动力学应激反应，提高唤醒质量，减低术中知晓发生率，不延长唤醒时间，有效提高手术安全系数。

Impact of dexmedetomidine-sevoflurane anesthesia on intraoperative wake-up test in children patients undergoing scoliosis surgery

Objective:To observe the effects of 0.4 μg/(kg·h)dose of dexmedetomidine on intra-operative wake-up test in children patients undergoing scoliosis surgery.Methods:Sixty patients for pos-terior scoliosis correction (ASA Ⅰ -Ⅱ,aged 5 -16 years)from March 2013 to April 2015 were en-rolled in this prospective,double-blinded,randomized,placebo-controlled study,The patients were ran-domly classified into two groups to receive dexmedetomidine (group RD,n =30)or saline solution (group R,n =30).In group RD,dexmedetomidine 0.4 μg/(kg·h)]was administered after tracheal intubation,while the equal volume saline solution was given instead in group R.Anesthesia was induced with midazolam,propofol,sufentanyl and cisatracurium,and anesthesia was maintained with sevoflurane inhalation and a continuous intravenous infusion of remifentanil in the both groups.BIS(bispectral index, BIS)value was maintained at 40 -60,and mean arterial pressure (MAP)was maintained at ≥ 60 mm-Hg before the wake-up test.When the wake-up test was performed,immediately the dexmedetomidine and remifentanil infusion were stopped,and the end-tidal concentration of sevoflurane was adjusted to 0. Mean arterial pressure,and heart rate (HR)were recorded before anesthesia and at 5-minute intervals during the wake-up test.The wake-up test time,arousal quality and sedation scores were recorded also. In addition,the data were also gathered on the dosage of ephedrine and atropine were used,as well as the intraoperative awareness in the patients who were followed up on the first day after the operation.Re-sults:There were no differences between group RD and group R with regard to HR and MAP at getting into the operation room (t =-1.460,P =0.150; t =-1.015,P =0.315 ).In group RD,no evi-dence was found for a difference in HR and MAP at awakening up versus at getting into the operation room (t =0.974,P =0.340;t =-1.449,P =0.161),while in group R,an increase in HR and MAP occurred at awakening versus at getting into the operation room (t =-2.106,P =0.044;t =-2.352, P =0.026).There were no significant differences in sedation scores and wake-up test time between the two groups(t =1.986,P =0.052;t =0.392,P =0.697).The wake-up test quality was significantly bet-ter in group RD than in group R (t =-2.098,P =0.041).HR in group RD was significantly lower than that in group R at any time point during the wake-up test (P <0.05).Four patients had awareness oc-currence during the operation in group R,and no awareness occurrence in group RD.Conclusion:Dexmedetomidine,when administered at a rate of 0.4 μg/(kg·h)as an adjuvant of sevoflurane inhala-tional anesthesia,could improve the wake-up test quality,and maintain hemodynamic stability during scoliosis surgery.