Effect Of Transcutaneous Electrical Acupoint Stimulation On Cardiovascular Response And Limb Ischemia-reperfusion Injury Induced By Tourniquet

Objective:To explore the effect of transcutaneous electrical acupoint stimulation on cardiovascular response and limb ischemia-reperfusion injury（IRI）induced by tourniquet.Methods:Sixty patients of both sexes,aged 40⁶5yr,with body mass index of 20³0 kg/m²,of American Society of Anesthesiologists physical statusⅠorⅡ,undergoing elective lower extremity surgery under combined spinal-epidural anesthesia,were randomly divided into 2 groups（n=30 each）:TEAS group（group T）and control group（group C）.After anesthesia,Patients in group T received continuous TEAS at the bilateral points of Neiguan and Hegu until the tourniquet deflates.In group C,electrodes were applied on the same acupoints,without electrical stimulation.Mean arterial pressure（MAP）and heart rate（HR）were recorded at regular time points:before TEAS（T₀）,before tourniquet inflation（T₁）,30 min after tourniquet inflation（T₂）,60 min after tourniquet inflation（T₃）,1 min after tourniquet deflation（T₄）,3 min after tourniquet deflation（T₅）,5 min after tourniquet deflation（T₆）,10 min after tourniquet deflation（T₇）.Low-frequency（LF）power and high-frequency（HF）power were recorded at T_0-3,T₆ and T₇.And the ratio of LF to HF（LF/HF）was calculated.Peripheral venous blood samples were collected at T₀,30 min（T₈）and 6 h（T₉）after tourniquet exhalation for measurement of serum levels of tumor necrosis factor-α（TNF-α）,interleukin-6（IL-6）,（MDA）and superoxide dismutase（SOD）.Results:There was no significant difference in MAP and HR between the two groups at different time points（P>0.05）.The LF in group T was higher than that in group C at T_2-3 and T_6-7（P<0.05）,and the HF in group T was higher than that in group C at T_1-3（P<0.05）.The LF/HF in group T was lower than that in C group at T₁,and was higher than that in group C at T₆（P<0.05）.Compared with group C,the concentration of serum TNF-αwas decreased at T_8-9,and the concentration of serum IL-6 was decreased at T_9,and the activity of serum SOD was increased at T₉ in group T（P<0.05）.Conclusion:Although TEAS has no obvious effect on hemodynamic changes induced by tourniquet,it can increase the activity of vagus nerve and sympathetic nerve during the tourniquet inflatable period,and increase the sympathetic nerve activity and promotes the balance of autonomic nerve to the dominant direction of sympathetic nerve activity after the tourniquet release in a short time.By reducing the concentration of TNF-α,IL-6 and enhancing the activity of SOD in patients’serum,TEAS can alleviate limb IRI induced by tourniquet to some extent.