title: Obesity and postoperative oxygenation after coronary artery bypass grafting.
abstract: OBJECTIVE
  The relationship between obesity and postoperative oxygenation after coronary artery bypass grafting was studied.
  
  
  METHODS
  Subjects were 68 patients undergoing solitary coronary artery bypass grafting--49 men and 19 women with a mean age of 64 years--divided into 3 groups by body mass index: group L with a body mass index of < 20 kg/m2 (n = 10), group M with a 20 < or = body mass index < 25 (n = 46), and group H with a 25 < or = body mass index (n = 12). Perioperative oxygenation was evaluated using respiratory indices measured preoperatively and 3 and 15 hours postoperatively.
  
  
  RESULTS
  Postoperative respiratory indices significantly increased from 0.23 to 0.67 (p < 0.001) at 3 hours and to 0.97 (p < 0.01) at 15 hours postoperatively in group L, from 0.27 to 0.80 (p < 0.001) and to 0.94 in group M, and from 0.31 to 1.39 (p < 0.001) and to 1.45 in group H. The postoperative respiratory index in group H was significantly higher (p < 0.01) than that in groups M and L both at 3 and 15 hours postoperatively. Multivariate analysis showed that the coefficients of determination of body mass index to postoperative respiratory index, 23% at 3 hours and 16% at 15 hours postoperatively, were the highest among perioperative factors.
  
  
  CONCLUSIONS
  Obesity is a major factor impairing postoperative oxygenation. Careful management in a semirecumbent position and/or nasal intermittent positive pressure ventilation may thus be required in obese patients.
authors.affiliation: Second Department of Surgery, Gunma University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamagishi
authors.forename: S
authors.initials: S
authors.lastname: Ishikawa
authors.forename: A
authors.initials: A
authors.lastname: Ohtaki
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: S
authors.initials: S
authors.lastname: Ohki
authors.forename: Y
authors.initials: Y
authors.lastname: Morishita
mesh_terms: D015992:Body Mass Index; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D010100:Oxygen / Q000378:metabolism*; D011184:Postoperative Period
chemical_list: D010100:Oxygen