Effect Of Dexmedetomidine Combined With Femoral Nerve Block On Tourniquet Reaction

Objective:To observe the effect of dexmedetomidine combined with femoral nerve block on tourniquet reaction and ischemia-reperfusion injury in patients undergoing general anesthesia for lower extremity surgery.Methods:Eighty patients who underwent elective lower limb fracture surgery in the Second hospital of Shanxi Medical University from January 2017 to June 2018 were randomly divided into dexmedetomidine group?group A?,femoral nerve block group?group B?,dexmedetomidine combined with femoral nerve block group?group C?,and the general anesthesia control group?group D?,20 cases in each group,the four groups were performed with conventional general anesthesia induction and total intravenous maintenance.The contents of malondialdehyde?MDA?in venous blood was measured of before nerve block?X₀?and 15min after tourniquet release?X₁?.The mean arterial pressure?MAP?and heart rate?HR?were recorded before tourniquet inflation?T₀?and the tourniquet was inflated for 30min?T₁?,45min?T₂?,60min?T₃?and 90min?T₄?.Results:There was significant difference in MDA content between group A?group B?group C and group D?P<0.05?,and the content of MDA at the time of X₁ was higher than that at the time of X₀;at the time of X₀,there was no significant difference in MDA contentbetween the four groups?P>0.05?.At the time of X₁,there was significant difference in MDA content between the four groups,and the results of pairwise comparison showed that the content of MDA in group D was the highest,that in group A and B was the second,and that in group C was the lowest,and the difference was statistically significant?P<0.05?,There was no significant difference between group A and group B?P>0.05?.The MAP,HR levels at the time of T₁-T₄ in group A?group B?group C and group D were higher than those in the same group at the time of T₀,but there was no significantdifference between T₁ and T₀?P>0.05?.There was significant difference between each time of T₂-T₄ and T₀?P<0.05?.There was no significant difference in MAP?HR levels among the four groups at the time of T₁and T₀?P>0.05?.At the time of T₂-T₄,there was significant difference in MAP?HR levels among the four groups,and the results ofpairwise comparison showed that the MAP?HR levels in group D was the highest,that in group A and B was the second,and that in group C was the lowest,and the difference was statistically significant?P<0.05?,There was no significant difference between group A and group B?P>0.05?.Conclusion:Dexmedetomidine combined with femoral nerve block can effectively reduce tourniquet reaction and ischemia-reperfusion injury.