title: Risk factors for hypoxemia after surgery for acute type A aortic dissection.
abstract: OBJECTIVE
  Postoperative hypoxemia is a frequent complication of surgery for acute type A aortic dissection. We tried to determine the factors associated with postoperative hypoxemia.
  
  
  METHODS
  Between 1997 and 2003, 114 patients underwent surgery for acute type A aortic dissection. Multivariate logistic regression analysis was done to identify the independent predictors of postoperative hypoxemia, defined by an arterial partial oxygen/inspired oxygen fraction (PaO(2)/FiO(2)) ratio of 200 or lower.
  
  
  RESULTS
  The overall in-hospital mortality was 6.1% (7 of 114 patients), being 5.2% in the hypoxemia group and 6.9% in the non-hypoxemia group. The ventilation time and intensive care unit stay were significantly longer in the hypoxemia group than in the non-hypoxemia group (P = 0.0044, P = 0.038, respectively). Logistic regression identified the following variables as predictors for postoperative hypoxemia: body mass index > or = 25 (odds ratio [OR], 5.6; 95% confidence interval [CI], 2.1-15.01; P < 0.001), preoperative PaO(2)/FiO(2) ratio < or = 300 (OR, 2.6; 95% CI, 1.09-6.13; P = 0.031), and the volume of transfused blood (OR, 1.08; 95% CI, 1.01-1.18; P = 0.037).
  
  
  CONCLUSIONS
  Initiating early treatment for hypoxemia and reducing the volume of blood transfused intraoperatively may improve the postoperative clinical course of obese patients with preoperative hypoxemia.
authors.affiliation: Department of Cardiovascular Surgery, Iwate Medical University Memorial Heart Center, Iwate Medical University, 1-2-1 Chuodori, Morioka 020-8505, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakajima
authors.forename: Kohei
authors.initials: K
authors.lastname: Kawazoe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Izumoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kataoka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Niinuma
authors.forename: Nobuo
authors.initials: N
authors.lastname: Shirahashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000401:mortality / Q000601:surgery*; D001014:Aortic Aneurysm / Q000401:mortality / Q000601:surgery*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010100:Oxygen / Q000032:analysis; D010313:Partial Pressure; D011183:Postoperative Complications; D012307:Risk Factors
chemical_list: D010100:Oxygen