Independent risk factors of hypoxemia in patients after surgery with acute type A aortic dissection.

BACKGROUND This study aimed to investigate independent risk factors of postoperative hypoxemia in patients with acute type A aortic dissection (ATAAD). METHODS A single-center retrospective study was conducted with enrolled 75 ATAAD patients following surgery, which were stratified into three groups on the basis of the postoperative PaO2/FiO2 ratio: severe hypoxemia group (PaO2/FiO2 ratio ≤100 mmHg); moderate hypoxemia group (100 mmHg < PaO2/FiO2 ratio ≤200 mmHg); and non-hypoxemia group (PaO2/FiO2 ratio >200 mmHg). The patient's demography, perioperative laboratory results, operative details, clinical outcomes were collected and analyzed. Univariable and multivariable analyses were performed and logistic regression model was established. RESULTS The incidence of postoperative severe hypoxemia and hypoxemia was 32% and 52%, respectively. Among the three groups, severe hypoxemia group exhibited a high significance of body mass index (BMI) and preoperative white blood cell (WBC) and main distribution of hypertension; meanwhile, Marfan syndrome was mainly distributed in non-hypoxemia group. On intensive care unit (ICU) admission, severe hypoxemia group exhibited a high significance of Acute Physiology and Chronic Health Evaluation (APACHE II) score of postoperative patients, and more patients would present shock. Moreover, severe hypoxemia group patients had a higher incidence of postoperative acute kidney injury (AKI) and usage of renal replacement therapy, longer length of stay (LOS) of ICU, and shorter 28 days ventilator-free days (VFDs). CONCLUSIONS The incidence of postoperative hypoxemia was high in ATAAD patients owing to comprehensive high-risk factors. Besides, postoperative complications negatively impacted their clinical outcomes.