右美托咪定与肾上腺素作为局部麻醉药佐剂对臂丛神经阻滞效果的对比

目的 对比常用剂量的右美托咪定(dexmedetomidine,Dex)和肾上腺素作为罗哌卡因的佐剂对锁骨上臂丛神经阻滞影响的差异. 方法 选择Colle's骨折患者60例,ASA分级Ⅰ、Ⅱ级,其中男性40例,女性20例;年龄44～68岁,体重50～75kg.采用随机数字表法分为3组(每组20例):生理盐水对照组(C组)、Dex组(D组)和肾上腺素组(E组).各组均在超声引导下行锁骨上臂丛神经阻滞.C组使用1 ml生理盐水,D组将0.75 μg/kg Dex稀释至1 ml,E组将盐酸肾上腺素100 μg稀释至1 ml.上述溶液分别加入10 ml 1％盐酸罗哌卡因和10 ml生理盐水配制的局部麻醉药物中.比较感觉及运动阻滞的起效时间、持续时间、开始静脉镇痛的时间,入室时(T0)及给药后10 min(T1)、20min(T2)、30 min(T3)、40 min (T4)、50 min(T5)、60 min(T6)的HR、MAP、SpO2、BIS以及麻醉并发症的情况. 结果 D组感觉、运动阻滞的起效时间比C、E组短,差异有统计学意义(P＜0.05),而C、E两组间差异无统计学意义(P＞0.05).D、E两组感觉、运动阻滞的持续时间、静脉镇痛的开始时间均比C组晚,差异有统计学意义(P＜0.05),但两组间差异无统计学意义(P＞0.05).MAP的组间比较,D组在T4～T5时段低于C组,在T3～T5时段低于E组,差异有统计学意义(P＜0.05).E组在T3时刻高于C组,差异有统计学意义(P＜0.05).HR的组间比较,D组在T3～T6时段低于C,E两组,E组在T3～T5时段显著高于C组,差异有统计学意义(P＜0.05).BIS值的组间比较,D组在T2～T6时段显著低于C、E组,差异有统计学意义(P＜0.05). 结论 与100 μg肾上腺素相比,0.75 μg/kg Dex具有类似的增强臂丛神经阻滞的作用,还具有镇静及降低心血管应激的作用,适用于肾上腺素禁忌证者.

Comparison of dexmedetomidine and epinephrine as the adjuvant to local anesthetic agents for brachial plexus block

Objective To compare the effect of dexmedetomidine (Dex) with epinephrine as adjuvant to ropivacaine in supraclavicular brachial plexus block.Methods Sixty patients,ASA Ⅰ or Ⅱ,44-68 years old,weight 50-75 kg,scheduled for fixation of Colle's fracture under ultrasound-guided supraclavicular brachial plexus block were divided randomly into three groups (n=20) with random number table,double-blinded fashion.In group C,1 ml normal saline was used.In group D,0.75 μg/kg Dex was diluted into 1 ml.In group E,epinephrine(100 μg) was diluted into 1 ml.The adjuvant was added to local anesthetic drug composed by 10 ml 1％ hydrochloride ropivacaine and 10 ml normal saline.Onset time of sensory and motor block,duration of analgesia,onset time of postoperative analgesia was recorded in three groups.MAP,HR,SpO2,BIS and anesthetic complications were recorded in time points of before (T0) and 10 min (T1),20 min (T2),30 min (T3),40 min (T4),50 min (T5),60 min (T6) after administration.Results The onset of sensory and motor block in group D are earlier than group C and E (P＜0.05).Duration of sensory block and motor block in group D and E were significantly longer than group C (P＜0.05).The needs for postoperative analgesia in D and E were postponed.The MAP in group D is lower than group C at T4-T5 and E at T3-T5 (P＜0.05).The MAP in group E is higher than group C at T3 (P＜ 0.05).Group D had lower HR than group C and E from T3 to T6 (P＜0.05).The HR in group E is higher than group C from T3 to T5.Group D had significantly lower BIS score than group C and E since T2 (P＜0.05).Conclusions Perineural 0.75 μg/kg of Dex has similarly ability of 100 μg epinephrine to enhance the quality and duration of analgesia in supraclavicular brachial plexus block.Dex has the ability to decrease cardiovascular stress and sedation,and should be a better adjuvant to local anesthesia in patients who are cautioned against epinephrine.