Effect Of Limb Ischemic Conditioning On Lung Injury In Adults Undergoing Valve Replacement Surgery

Objective:The present study is aimed to investigate whether limb ischemic preconditioning(LIPC) or limb ischemic post-conditioning (LPostC),an intervention in which brief ischemic of one tissue or organ protect remote organs from a sustained episode of ischemia reperfusion injury, is beneficial for patient undergoing valve replacement surgery.Methods:48 adult patients undergoing valvular replacement surgery were randomly assigned to three groups:LIPC group (16), LPostC group (16) and control group (16). LIPC consisted of three 5-min cycles of left leg ischemia, induced by a manual cuff-inflator placed on the left leg and inflated to 240mmHg, with an intervening 5 min of reperfusion during which the cuff was deflated. The processing time was before surgery after induced. LPostC was the same process to the RIPC, but the processing time was five minutes after aortic cross-clamping prior to open aortic, serum human-pulmonary surfactant associated protein(SP-A), tumor necrosis factor-alpha(TNF-α) and arterial carbon dioxide tension (PaCO2), arterial oxygen tension (PaO2), inspired oxygen concentration (FiO2) were measured before anesthesia and cardiopulmonary bypass(CPB),6,24hr after CPB. At the same time, blood was extracted from left and right atrium before aortic cannulation and aortic opening 10min, measuring the number of neutrophils to calculate stranded in the number of neurophils in the lungs.Results:(1)LIPC or LPostC significantly reduced the overall serum SP-A, TNF=αlevels and improved the oxygenation index (01) and respiratory index (RI) after CPB.(2)Serum markers (SP-A, TNF-a concentrations), pulmonary function index (RI,OI), and the number of polymorphonuclear neutrophils (PMNs) were no significant statistical difference between LIPC and LPostCConclusion:(1)CPB can cause lung injury, the degree of lung injury was positively correlated with CPB time.LIPC or LPostC can't be completely avoid lung injury.(2)Patients undergoing valvular replacement surgery could benefit from LIPC or LPostC, using transient leg ischemia.(3)LPostC and LIPC had same protective effect on the lung injury after CPB.