Age >70, emergent surgery, perioperative blood transfusions, reintubation and days of MV are the risk factors for VAP in patients following cardiac surgery. P. aeruginosa, P. klebsiella, S. aureus, and Acinetobacter baumannii were the main pathogens of VAP. According to the cause of VAP, active prevention and treatment measures should be developed and applied to shorten the time of MV and improve chances of survival.

Objectives:To determine risk factors associated with postoperative hypoxemia after surgery for acute type A aortic dissection.Methods:We retrospectively analyzed the clinical data of 192 patients with acute type A aortic dissection who underwent surgery in Qingdao Municipal Hospital, Medical College of Qingdao University, Qingdao, China between January 2007 and December 2013. Patients were divided into hypoxemia group (n=55) [arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ≤200 mm Hg] and non-hypoxemia group (n=137) [PaO2/FiO2 >200 mm Hg]. Perioperative clinical data were analyzed and compared between the 2 groups.Results:The incidence of postoperative hypoxemia after surgery for acute aortic dissection was 28.6% (55/192). Perioperative death occurred in 13 patients (6.8%). Multivariate regression identified body mass index (BMI) >25 kg/m2 (OR=21.929, p=0.000), deep hypothermic circulatory arrest (DHCA) (OR=11.551, p=0.000), preoperative PaO2/FiO2 ≤300 mm Hg (OR=7.830, p=0.000) and blood transfusion >6U in 24 hours postoperatively (OR=12.037, p=0.000) as independent predictors of postoperative hypoxemia for patients undergoing Stanford A aortic dissection surgery.Conclusion:Our study demonstrated that BMI >25 kg/m2, DHCA, preoperative PaO2/FiO2 ≤300 mm Hg, and blood transfusion in 24 hours postoperatively >6U were independent risk factors of the hypoxemia after acute type A aortic dissection aneurysm surgery.

This analysis suggests that levosimendan might reduce renal injury in adult patients undergoing cardiac surgery. More prospective randomized studies are needed to further demonstrate the benefits of levosimendan on renal protection in cardiac surgery.