Acute respiratory distress syndrome following cardiac surgery severely affects the prognosis of patients; the mortality is up to 40%. Although experience many years of research and exploration, the effective methods for the treatment of acute respiratory distress syndrome is still relatively limited at present, including lung protective mechanical ventilation respiratory support, fluid management, glucocorticoid and other integrated organ function maintenance measures. It is currently the research of acute respiratory distress syndrome aims at the early discovery and takes effective measures to prevent its occurrence, hoping to improve the prognosis of patients. According to risk factors is established through the analysis of lung injury score early warning system, the early identification of acute respiratory distress syndrome patients at high risk, before the occurrence of acute respiratory distress syndrome take corresponding preventive measures can effectively reduce the incidence rate and mortality. So far, domestic and foreign research on the establishment of acute respiratory distress syndrome scoring early warning system is less. Cardiac surgery has significant characteristics, type of operation, location, operation, intraoperative blood transfusion and oxygenation, postoperative factors, are likely to be the factors of acute respiratory distress syndrome. As far as investigators know, so far there are few specialized for acute respiratory distress syndrome predicting lung injury after cardiac surgery. This study will be completed after the implementation of individualized dynamic lung injury score evaluation of cardiac surgery patients, identification of high-risk acute respiratory distress syndrome patients, to assist clinicians in early decision, take preventive measures. This study will improve the prognosis of acute respiratory distress syndrome patients after cardiac surgery; it is of great significance to improve the level of intensive care after cardiac surgery.