Obesity and postoperative oxygenation after coronary artery bypass grafting.
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.
Yamagishi
T
T
Second Department of Surgery, Gunma University School of Medicine, Japan.
Ishikawa
S
S
Ohtaki
A
A
Takahashi
T
T
Ohki
S
S
Morishita
Y
Y
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
D010100:Oxygen