Effect Of Different Tourniquet Deflation Methods On Cardiac Troponin â…  Of Elderly Patients During Operation

Objective To investigate effect of different tourniquet deflation methods oncardiac troponin â…  of elderly patients during operation.Methods A total of40elderly patients with unilateral lower limb surgery were chosen.They were randomly and equally divided into the control group（group A）and study group（group B）．the one-stage deflation controlled by tourniquet deflation equipment was used inthe control group．And in study group the tourniquet was slowly deflated to200mmHg, rest aminute，Then slowly deflated to100mmHg, after rest a minute slowly deflated to0mmHg.HR、MAP、PETCO₂、PEEK were recorded just1min before tourniquet inflation （H₀）,1minbefore tourniquet deflation（H₁） and1min （H₂）、3min （H₃）、5min（H₄）、10min（H₅）、30min（H₆）after tourniquet deflation. Arterial blood for measuring arterial partial pressure of oxygen（PaO₂）、arterial partial pressure of carbon dioxide （PaCO₂）、PH、base excess （BE）、Na+^、K+^were taken just1min before tourniquet inflation（H₀）,and5min（H₄）、30min （H₆） aftertourniquet deflation. Plasma samples for measuring the concentration of cardiac troponin Ⅰ（cTnⅠ） was taken just1min before tourniquet inflation（T0）,and1h （T1）,6h（T2） after tourniquetdeflation.Results Compared with H₀point, HR increased at H₁、H₂、H₃、H₄、H₅points（P＜0.05），MAP increased at H₁point （P＜0.05） and decreased at H₂、H₃、H₄points（P＜0.05）， PaCO₂increased at H₄points（P＜0.05），PETCO₂increased at H₂、H₃、H₄points（P＜0.05），PH、BEdecreased at H₄point （P<0.05）, K+ⁱncreased at H₄、H₆points（P＜0.05） in group A and B,HRat H₃、H₄points in group B were lower than that in group A（P＜0.05）, MAP at H₂、H₃、H₄points in group B were higher than that in group A（P＜0.05）,PaCO₂at H₄points in group B was lower than that in group A（P＜0.05）, PETCO2at H3、H4points in group B were lowerthan that in group A（P＜0.05），PH、BE at H4points in group B were higher than that in groupA（P＜0.05）. Compared with T0point, The concentration of cTnâ…  in T2point was increased ingroup A and group B（P<0.05），But the concentration of cTnâ…  at T2points in group B wassignificantly less than that in group A（P＜0.05）.Conclusion the tourniquet pressure for300mmHg can also impact on cTnâ…  of elderlypatients within the security limited time.Fractional slowly deflation of tourniquet using inpatients with lower limb surgery not only can keep respiration、circulation and blood gassmoothly,but aslo can reduce the influence of cTnâ…  after tourniquet release.