Objective To evaluate the feasibility of using lumbar plexus block for unilateral extremity artificial vascular graft between femoral artery and deep femoral artery in elderly patients.Methods Forty ASA physical status Ⅱ or Ⅲ patients,aged 67-81 yr,weighing 47-65 kg,scheduled for extremity artificial vascular graft between femoral artery and deep femoral artery,were randomly divided into 2 groups (n =20 each) using a random number table:spinal anesthesia group (group S) and lumbar plexus block group (group L).In group S,0.5 ％ hyperbaric ropivacaine 3 ml was injected into the subarachnoid space.In group L,lumbar plexus block was performed with 30 ml of 0.5 ％ ropivacaine under the guidance of a nerve stimulator.The onset time and duration of sensory block,anesthetic efficacy,and requirement for ephedrine and volume of fluid infused during operation,and development of lumbar plexus block-related adverse events were recorded.Results Compared with group S,the onset time and duration of sensory block were significantly prolonged,the requirement for ephedrine and volume of fluid infused during operation were decreased,and no significant change was found in anesthetic efficacy in group L.No lumbar plexus block-related adverse events developed in group L.Conclusion Lumbar plexus block can be used for unilateral extremity artificial vascular graft between femoral artery and deep femoral artery in elderly patients.

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.