Independent risk factors for hypoxemia after surgery for acute aortic dissection

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 (PaO(2))/fraction of inspired oxygen (FiO(2)) ≤200 mm Hg] and non-hypoxemia group (n=137) [PaO(2)/FiO(2) >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/m(2) (OR=21.929, p=0.000), deep hypothermic circulatory arrest (DHCA) (OR=11.551, p=0.000), preoperative PaO(2)/FiO(2) ≤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/m(2), DHCA, preoperative PaO(2)/FiO(2) ≤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.