右美托咪定对超声引导下罗哌卡因臂丛神经阻滞效果的影响

目的 观察右美托咪定对超声引导下臂丛神经阻滞时效的影响.方法 择期上肢手术患者60例,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将患者随机分为2组（均为30例）：右美托咪定组（D组）和对照组（C组）.行超声引导下肌间沟臂丛神经阻滞,定位成功后,D组和C组分别注射右美托咪定1 ml（1μtg/kg）＋0.5％盐酸罗哌卡因30 ml和生理盐水1 ml＋0.5％盐酸罗哌卡因30 ml,记录感觉和运动神经阻滞起效时间、作用时间、镇痛维持时间;记录患者入室时（T0）、阻滞后5 min（T1）、10 min（T2）、15 min （T3）、30 min （T4）、60 min （T5）各时间点的心律（HR）、平均动脉压（MAP）、血氧饱和度（SpO2）;记录不良反应发生情况.结果 与C组比较,D组感觉和运动神经阻滞起效时间缩短感觉：（9.8±3.2）min比（7.4±2.1）min;运动：（12.3±2.5） min比（8.2±1.6）min],作用时间及镇痛维持时间延长（P＜0.05）.与C组比较,T1～T5时D组HR减慢（P＜0.05）,MAP差异无统计学意义.两组术中SpO2差异无统计学意义.D组术中有3例发生心动过缓.两组均未发生低血压、局麻药中毒等不良反应.结论 右美托咪定1μg/kg联合0.5％盐酸罗哌卡因30 ml用于超声引导下臂丛神经阻滞,可明显缩短起效时间、延长作用时间及镇痛时间,但需注意心动过缓的发生.

Effects of dexmedetomidine on ultrasound-guided brachial plexus blockade using ropivacine

Objective To examine the effects of dexmedetomidine on ultrasound-guided brachial plexus blockade by ropivacaine.Methods Sixty patients with ASA gradings of Ⅰ or Ⅱ scheduled for surgery of upper extremities under brachial plexus blockade guided by ultrasonography were randomly allocated to dexmedetomidine group （group D,n=30） and control group （group C,n=30）,respectively.Following successful positioning,groups C and D were subject to 30 ml ropivacaine （0.5％） plus 1 ml normal saline and plus 1 ml dexmedetomidine （1 μg/kg） injection,respectively.The onset of motor and sensory blockade,the duration of blockade and the time for analgesia were recorded.The heart rate （HR）,mean arterial blood pressure （MAP）,pluse oxygen saturation （SpO2） and adverse events during entry to the operation room （T0） and at 5 （T1）,10 （T2）,15 （T3）,30 （T4） and 60 minutes （T5） were monitored.Results Compared with group C,group D was associated with a shorter time of onset of motor （12.3±2.5） min vs （8.2±1.6）min,P＜0.05] and sensory blockade （9.8±3.2）min vs （7.4±2.1）min,P＜0.05] as well as a prolonged duration of motor and sensory blockade （both P＜0.05）.Compared with group C,group D yielded a significantly reduced HR at T1-T5.However,the difference in MAP and SpO2 was unremarkable.Bradycardia was identified in 3 cases in group D.No events of hypotension and toxication of analgesics were observed.Conclusions Dexmedetomidine （1 μg/kg） in combination with 30 ml ropivacaine （0.5％） for brachial plexus blockade guided by ultrasonography can shorten the time of onset and prolong the duration of analgesia.However,the potential risks of badycardia warrant meticulous monitoring.