右美托咪定对周围神经阻滞下行下肢手术患者止血带反应的影响

Effects of dexmedetomidine on responses to tourniquet in patients undergoing lower extremity surgery with peripheral nerve block

目的 评价右美托咪定对周围神经阻滞下行下肢手术患者止血带反应的影响.方法 择期B超引导下腘窝坐骨神经阻滞联合股动脉旁隐神经阻滞下行足部手术患者80例,年龄22~63岁,体重47~81kg,性别不限,ASA分级Ⅰ或Ⅱ级,采用随机数字表法分为2组(n=40):对照组(C组)和右美托咪定组(D组).D组静脉输注右美托咪定1 μg/kg,输注时间10 min,C组静脉输注等量生理盐水.于上止血带前(T0)、松开止血带30 min(T1)和松开止血带60 min(T2)时采集颈内静脉血标本,测定血浆C-反应蛋白(CRP)、TNF-α、MDA和SOD水平;记录出现止血带反应时间、止血带耐受时间和止血带耐受间期;记录低血压、心动过缓、恶心呕吐等的发生情况.结果 与T0时比较,2组T12时血浆CRP 、TNF-α和MDA浓度升高,SOD活性降低(P<0.05);与C组比较,D组T12时血浆CRP、TNF-α和MDA浓度降低,SOD活性升高,出现止血带反应时间、止血带耐受时间和止血带耐受间期延长,心动过缓发生率升高(P<0.05).结论 右美托咪定可减轻周围神经阻滞下行下肢手术患者的止血带反应.

Objective To evaluate the effects of dexmedetomidine on responses to tourniquet in patients undergoing lower extremity surgery with peripheral nerve block.Methods Eighty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes,aged 22-63 yr,weighing 47-81 kg,scheduled for elective foot surgery under ultrasound-guided popliteal sciatic nerve block combined with saphenous nerve block,were divided into 2 groups (n =40 each) using a random number table method:control group (group C) and dexmedetomidine group (group D).Dexmedetomidine was intravenously infused for 10 min in a dose of 1 μg/kg in group D,and the equal volume of normal saline was given instead in group C.Blood samples were taken from the internal jugular vein before using the tourniquet (T0) and at 30 and 60 min after releasing the tourniquet (T1-2) for determination of the levels of c-reactive protein (CRP),tumor necrosis factor-alpha (TNF-α),methane dicarboxylic aldehyde (MDA) and superoxide dismutase (SOD) in plasma.The time to responses to tourniquet,tourniquet tolerance time and tourniquet tolerance period were recorded.The occurrence of hypotension,bradycardia and nausea and vomiting was also recorded.Results Compared with the baseline at T0,the concentrations of plasma CRP,TNF-α and MDA were significantly increased and the activity of plasma SOD was decreased at T1,2 in the two groups (P<0.05).Compared with group C,the concentrations of plasma CRP,TNF-α and MDA were significantly decreased and the activity of plasma SOD was increased at T1,2,the time to responses to tourniquet,tourniquet tolerance time and tourniquet tolerance period were prolonged,and the incidence of bradycardia was increased in group D (P<0.05).Conclusion Dexmedetomidine can reduce responses to tourniquet in patients undergoing lower extremity surgery with peripheral nerve block.