右美托咪定和咪达唑仑持续泵注用于区域麻醉下显微外科手术中镇静效果的比较

Comparison the sedative effects of dexmedetomidine with midazolam by continuing infusion during microsurgery under regional block

目的将右美托咪定（dexmedetomidine，Dex）和咪达唑仑分别用于区域麻醉下显微外科手术中镇静，对其效果及安全性进行比较。方法60例拟在区域麻醉下行前臂和手部手术的急诊手外科患者，采用随机数字表法将其分为Dex组（D组）和咪达唑仑组（c组），每组30例，应用警觉／镇静评分（observers assessment of alertness／sedation scale，OAA／S）和脑电双频谱指数（bispectralindex，BIS）对两组患者术中镇静效果进行观察。两组分别在区域麻醉完善后，D组使用Dex，C组使用咪达唑仑静注至OAA／S镇静深度Ⅲ级并持续泵注维持该镇静水平至术终。观察用药前（T0）、切皮时（T1）、手术开始后15（T2）、30（T3）、60min（T4）、术毕（T5）及术后1h（T6）患者BIS、平均动脉压（mean arterial pressure，MAP）、心率（heartrate，FIR）、脉搏血氧饱和度的变化；对患者低血压、心动过缓、恶心、呕吐、烦躁等副作用及术中事件的遗忘率进行评估，记录术后血管危象的发生率。结果D组泵注Dex后，T1、T2、T3、T4、T5时点HR分别为[（74±14）、（74±13）、（72±12）、（70±11）、（75±11）次／min]，较T0时点[（82±15）次／min]显著下降（P〈0．05），D组T1、T2、T3、T4、T5时点MAP分别为[（78±12）、（77±14）、（76±13）、（78±12）、（79±12）mmHg（1mmHg=0．133kPa）]，较R[（87＋13）mmHg]明显下降（P〈0．05）；C组T1～T5时点HR较T0无明显改变（P〉0．05），T1时点MAP[（79±11）mmHg]较T0[（86±12）mmHg]显著下降（P〈0．05），T2～L时点MAP和L比较差异无统计学意义（P〉0．05）；组间比较，T1～T4时点D组HR明显低于c组（P〈0．05）。Dex产生的镇静效果和咪达唑仑组相似，两组T1～T5时OAA／S评分、BIS与T0比较明显降低（P〈0．05），D组、c组组问各时点OAA／S评分、BIS比较差异无统计学意义（P〉0．05）。D组有12例产生完全遗忘，6例不完全遗忘；C组18例产生完全遗忘，9例不完全遗忘，组问比较差异有统计学意义（P〈0．05）。两组问术中应用阿托品和麻黄碱例数、呼吸抑制、恶心、呕吐、烦躁及术后血管危象发生率差异无统计学意义（P〉0．05）。结论Dex和咪达唑仑均适合于区域麻醉下显微外科手术的镇静，在抗交感作用、减少出血、降低心肌耗氧量、镇静、遗忘方面各有优势。

Objective To compare the sedative effects and safety of dexmedetomidine （Dex） and midazolam by continuing infusion during microsurgery under regional block. Methods Sixty forearm or hand emergency wounded patients scheduled for microsurgical operation under regional anesthesia were randomly assigned to Dex group （group D） and midazolam group （group C）. Observers assessment of alertness/sedation scale （OAA/S） and bispectral index （BIS） values were used to observe the sedative ett^ct of Dex and midazolam during surgery. In all patients, the sedative drugs were intravenously administrated after the completion of regional block anesthesia. Moreover, BIS, mean arterial pressure （MAP）, heart rate （HR）, oxygen saturation and OAA/S scales were recorded at time-points of before administration （T0）, beginning of surgery （T1）, 15（T2）, 30（T3）, 60 min （T4）, post-operation instant （T5） and 1 h post-operation （T6）. The side effects of patients of the two groups were recorded. The cases of forgetting intraoperative events and the incidence of postoperative vascular crisis were also recorded. Results After administration of Dex, MAP and HR in group D at times of TI-T5 were significantly lower than To （P〈0.05）. HR at time-points of TI-T5 in group C were no significantly varied （P〉0.05）. MAP at time-point of T1 in group C was significantly decreased than To （P〈0.05） and MAP at time-points of T2-T5 in group C were not significantly varied （P〉0.05）. Comparison between groups, HR at times of T1-T4 in group D was significantly lower than that in group C. The values of BIS and OAA/S at time-points of T1-T5 were all significantly lower than To （P〈0.05） in D and C groups. There were no significant differences in BIS and OAA/S at each time point between the two groups （P〉0.05）. Twelve cases in group D showed total amnesia and six cases showed un-total amnesia. Eighteen cases in group C showed total amnesia and nine cases showed un-total amnesia. There were significant differences between the two groups （P〈0.05）. There were no significant difference between the two groups on the number of cases in application of atropine or ephedrine, incidence of respiratory inhibition, nausea, vomiting, irritability in operation and postoperative vascular crisis （P〉0.05）. Conclusions Dex and midazolam can also provide a good sedation with low respiratory, inhibition in microsurgery under regional anesthesia. They have their own advantages in anti-sympathetic nerve function, reducing bleeding, reducing myocardial oxygen consumption, sedation and amnesia.