Risk factor analysis of postoperative acute respiratory distress syndrome after type A aortic dissection repair surgery

To investigate the incidence, outcomes, and risk factors of postoperative acute respiratory distress syndrome (ARDS) in patients undergoing surgical repair for acute type A aortic dissection. This retrospective study involved 270 patients who underwent surgical repair for acute type A aortic dissection between January 2009 and December 2015. Data on clinical characteristics and outcomes were collected. Patients who immediately died after surgery and with preoperative myocardial dysfunction were excluded. The included patients were divided into the ARDS (ARDS patients who met the Berlin definition) and non-ARDS groups. Primary outcome was postoperative ARDS, according to the 2012 Berlin definition for ARDS and was reviewed by 2 qualified physicians with expertise in critical care and cardiac surgery. Outcomes of interest were the incidence and severity of risk factors for ARDS in this population, and perioperative outcomes and survival rates were compared with patients with or without ARDS. A total of 233 adult patients were enrolled into this study; of these, 37 patients (15.9%) had ARDS. Three, 20, and 14 patients had mild, moderate, and severe ARDS, respectively, according to the Berlin definition, with no significant difference in age, sex, and underlying disease. The ARDS group had lower mean oxygenation index (OI) than the non-ARDS group in the first 3 days post-surgery and demonstrated an improvement in lung function after the fourth day. Postoperative complication risks were higher in the ARDS group than in the non-ARDS group. However, no significant difference was observed in in-hospital mortality between the 2 groups (10.8% vs 5.6%, P=.268). Additionally, there was also no significant difference in the 3-year mortality rate between the 2 groups (P of log-rank test=.274). Postoperative hemoglobin level (odds ratio [OR]: 0.78; 95% confidence interval [CI]: 0.62-0.99) and perioperative blood transfusion volume (OR: 1.07; 95% CI: 1.03-1.12) were associated with ARDS risk. Postoperative ARDS after type A aortic dissection repair surgery was associated with risks of postoperative complications but not with risk of in-hospital mortality or 3-year mortality. A higher perioperative blood transfusion volume and a lower postoperative hemoglobin level may be risk factors for ARDS.