The Clinical Study Of The Relationship Between Expression Of TLR4and Ventilator-associated Pneumonia In Patient Undergoing Cardiac Surgery With Cardiopulmonary Bypass

Objective:The purpose of this study was to test the hypothesis thatventilator-associated pneumonia（VAP） after cardiac surgery with cardiopulmonarybypass requires TLR4-dependent signaling.Methods:Twenty patients were categorized into two groups base on development ofVAP following CPB, with VAP group(A) and without VAP group (B). The bloodsamples of left atrium were collected in both groups at the time points ofpreoperation(T1),20mins(T2),40mins(T3) and end(T4) of CPB. Expression of TLR4on granular leukocyte was detected with flow cytometry. The common and CPB dataof all cases in two groups were compared.Results：VAP occurred in8patients. CPB time in with VAP group was statisticallylonger than those in without VAP group. The expression of TLR4on granularleukocyte in with VAP group at the time points of T3and T4were significantly higherthan those in without VAP group.Conclusion: Longer CPB time promoted development of ventilator-associatedpneumonia after cardiac surgery with cardiopulmonary bypass requiresTLR4-dependent signaling.