摘要目的 观察右美托咪定对臂丛神经阻滞下上肢手术止血带反应的影响.方法 择期上肢手术患者80例,年龄25 ～ 65岁,体质量55～ 75 kg,身高155～ 175 cm,ASA分级Ⅰ或Ⅱ级.采用随机数字表法,将患者随机分为右美托咪定组(D组,n=40)和对照组(C组,n=40).D组于神经阻滞前10min静脉注射右美托咪定负荷剂量1 μg/kg,继之以0.5μg·kg-1·h-1的速率持续输注至手术结束.C组给予等量生理盐水.行超声引导下肌间沟臂丛神经阻滞,定位成功后两组均注射0.5％盐酸罗哌卡因30ml.记录两组止血带反应例数、止血带反应发生时间、止血带反应程度、术中辅助用药情况;记录患者入室时(To)、阻滞后5 min(T1)、10 min(T2)、15 min(T3)、30 min (T4)、60 min(T5)心率(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 D组止血带反应例数、止血带反应程度、术中辅助芬太尼用药剂量均低于C组[止血带反应例数:8/40比14/40,止血带反应程度:2.4±0.8比60.2±20.4,辅助芬太尼用药剂量:(4.2±1.2)μg比(130.3±38.6) 1μg,均P＜0.05],止血带反应发生时间迟于C组[(52.2±12.5)min比(30.2±11.8)min,P＜0.05)].To时C组与D组两组HR、MAP、SpO2差异无统计学意义;T1～T5时D组HR较C组减慢(均P＜0.05);T1～T3时两组MAP差异无统计学意义;T4、T5时点D组MAP明显低于C组(P＜0.05);两组术中SpO2差异无统计学意义.D组术中有4例发生心动过缓,两组均未发生低血压、局部麻醉药中毒等不良反应.结论 上肢神经阻滞前10 min静脉注射右美托咪定1 μg/kg,继之以0.5 μg·kg-1·h-1的速率持续输注至手术结束,可明显减少止血带反应例数、减轻止血带反应程度、推迟止血带反应发生时间.

abstractsObjective To investigate the effect of dexmedetomidine application on tourniquet reaction during upper extremity surgery.Methods Eighty ASA Ⅰ or Ⅱ patients aged 25-65 years,weighting 55-75 kg,height 155～175 cm,scheduled for upper extremity surgery were randomized into 2 groups:dexmedetomidine group (group D,n=40) and control group (group C,n=40).A loading dose of dexmedetomidine 1 μg/kg was administered intravenously 10 min before anaesthesia followed by infusion at 0.5 μg· kg-1 · h-1 until the end of operation in group D.While equal volume of normal saline was given in group C.Brachial plexus block was performed under the guidance of ultrasound.After successful location,30 ml of 0.5％ ropivacaine was injected in each group.The tourniquet reaction,tourniquet reaction occurring time,tourniquet reaction degree,adjuvant drug situation of two groups were recorded.Heart rate (HR),mean arterial pressure (MAP),oxygen saturation (SpO2) were recorded before the surgery (T0),and at 5 min (T1),10 min (T2),15 min (T3),30 min (T4),60 min (Ts) after blocking,as well as adverse reactions were recorded.Results Compared with group C,the cases of tourniquet reaction,tourniquet reaction degree,dosage of adjuvant fentanyl during the operation were significantly lower in group D [cases of tourniquet reaction:8/40 vs 14/40,tourniquet reaction degree:2.4±0.8 vs 60.2±20.4,dosage of adjuvant fentanyl during the operation:(4.2± 1.2)pg vs (130.3±38.6) μg,all P＜0.05].The tourniquet reaction occurring time of group D was later than that of group C [(52.2± 12.5)min vs (30.2±11.8)min,P＜0.05].There was no statistical significance of HR,MAP and SpO2 between group C and group D at T0.The level of HR was lower at T1-T5 in group D than that in group C (P＜0.05).There was no statistical significance of MAP at T1-T3 between the two groups.The MAP at T4 and T5 was significantly lower in group D than that in group C (P＜0.05).There was no statistical significance of SpO2 between two groups.Bradycardia was observed in 4 patients in group D.Hypotension,local anesthetic intoxication,and other adverse reactions were not found in two groups.Conclusion A loading dose of dexmedetomidine 1 μg/kg administered intravenously 10 min before anaesthesia followed by infusion at 0.5 μg· kg-1 · h-1 until the end of operation in upper extremity surgery can significantly reduce the tourniquet reaction cases,relieve tourniquet reaction degree and postpone the occurring time of tourniquet reaction.