High preoperative bradykinin level is a risk factor for severe postoperative hypoxaemia in acute aortic dissection surgery

New FindingsWhat is the central question of this study?Hypoxaemia can lead to increased postoperative mortality in patients: what are the independent risk factors for severe hypoxaemia after acute Stanford type A aortic dissection?What is the main finding and its importance?Severe postoperative hypoxaemia was found in 36.4% of patients, and it was determined that high preoperative bradykinin levels and increased BMI were independent predictors of severe postoperative hypoxaemia in patients with acute Stanford type A aortic dissection. For obese patients with high preoperative bradykinin levels, more attention should be paid to preventing severe postoperative hypoxaemia. Severe hypoxaemia after cardiac surgery is associated with serious complications and a high risk of mortality. The purpose of this study is to investigate the independent risk factors of severe postoperative hypoxaemia in patients with acute Stanford type A aortic dissection. We collected 77 patients with acute Stanford type A aortic dissection who underwent surgical treatment. The primary outcome was severe postoperative hypoxaemia (PaO2/FiO(2) <= 100 mmHg), and a multivariate logistic regression analysis was performed to assess the independent predictors of risk for this. A mixed-effects analysis of variance model and a receiver operating characteristic (ROC) curve were generated to evaluate the predictive probabilities of risk factors for severe postoperative hypoxaemia. A total of 36.4% of patients developed severe postoperative hypoxaemia. The multivariate logistic regression analysis identified high preoperative bradykinin level (odds ratio (OR) = 55.918, P < 0.001) and increased body mass index (BMI; OR = 1.292, P = 0.032) as independent predictors of severe postoperative hypoxaemia in patients with acute Stanford type A aortic dissection. The mixed-effect analysis of variance model and ROC curve indicated that high preoperative bradykinin level and BMI were significant predictors of severe postoperative hypoxaemia (area under the ROC curve = 0.834 and 0.764, respectively). High preoperative bradykinin levels and obesity were independent risk factors for severe postoperative hypoxaemia in patients with acute Stanford type A aortic dissection. For obese patients with high levels of bradykinin before surgery, clinicians should actively take measures to block bradykinin-mediated inflammatory reactions.