静脉输注右美托咪定对臂丛神经阻滞的影响

目的探讨静脉输注右美托咪定对行上肢手术患者臂丛神经阻滞时间的影响和术中镇静效果。方法拟B型超声引导下行肌间沟臂丛神经阻滞的上肢手术患者60例,随机分为2组,每组30例。实施臂丛阻滞后,右美托咪定组（D组）：静脉注射1 mL生理盐水后按0.5μg/kg输注右美托咪定负荷剂量,10 min后以0.2μg/（kg.h）维持。对照组（F组）：静脉注射1 mL氟芬合剂后,按D组输注方法输注等容量的生理盐水。评价感觉阻滞和运动阻滞的效果,记录感觉阻滞和运动阻滞的起效时间和持续时间,观察并记录患者麻醉前（T0）、输注负荷量即刻（T1）、持续输注10 min（T2）、20 min（T3）、30 min（T4）、60 min（T5）及手术结束（T6）的MAP、HR、SpO2及BIS值。观察并记录低血压、心动过缓、呼吸抑制、恶心呕吐及头晕等不良反应。术中主诉疼痛的患者静脉注射氟芬合剂1 mL,仍因疼痛不耐受手术的患者改为全麻。结果无一例患者使用补救用药或更改麻醉方式,D组患者感觉和运动阻滞持续时间明显长于F组（P〈0.05）;在T2～T5时间点,两组MAP、HR、BIS值、呼吸频率和血氧饱和度比较,差异有统计学意义（P〈0.05）。结论静脉输注小剂量右美托咪定不仅可以为行臂丛神经阻滞的患者提供充分镇静,而且明显延长臂丛神经感觉和运动阻滞的持续时间。

Effects of intravenous dexmedetomidine on brachial plexus block

Objective To study the nerve block time and intraoperative sedative effect of intravenous infusion of dexmedetomidine on upper extremity operation in patients with brachial plexus nerve block.Methods 60 patients scheduled for upper limb operation under the type B ultrasound guidance to black interscalene brachial plexus were randomly divided into 2 groups（n=30）.Dexmedetomidine group（group D）：intravenous injection of 1 mL NS followed by 0.5 μg/kg infusion of dexmedetomidine loading dose,then followed by infusion of 0.2 μg/（kg · h）after 10 min.Control group（group F）：intravenous injection of 1 mL droperidol-fentanyl,then the same volume of NS according to the infusion method in group D.Sensory and motor block onset time and block durations were recorded.The patients′ MAP,HR,SpO2 and BIS value were observed and recorded in the following time：before anesthesia（T0）,infusion of load instantly（T1）,continuous infusion of 10 min（T2）,20 min（T3）,30 min（T4）,60 min（T5）,end of operation（T6）.The hypotension,bradycardia,respiratory depression,nausea,vomiting,dizziness and other adverse reactions were also observed and recorded.When patients complained of pain,1 mL droperidol-fentanyl was given.Patients receiving general anesthesia in case of pain.Results No patient used remedy medication or changed the anesthesia mode.The sensory and motor nerve block duration of group D were significantly longer than those of group F（P0.05）.There were significant differences in MAP,HR,BIS,respiratory rate and oxygen saturation between the 2 groups at the T2~T5 time（P0.05）.Conclusion Intravenous infusion of small doses of dexmedetomidine can not only provide patients received brachial plexus blockade with adequate sedation,but also prolong the brachial plexus sensory and motor block duration.