Hypoxemia after gastric bypass surgery for morbid obesity
R. R. Taylor, T. M. Kelly, C. G. Elliott, R. L. Jensen and S. B. Jones
Fifty-six patients who underwent Roux-en-Y gastrojejunostomy for morbid
obesity had arterial blood gas analysis before surgery and during the first
five postoperative days. Preoperatively, seven subjects were hypoxemic and
three were hypercapneic. Twenty-four hours after gastric bypass, 75% of the
patients had an arterial oxygen pressure (Pao2) less than 60 mm Hg.
Compared with preoperative measurements, blood gas values on the first
postoperative day showed a 13.7-mm Hg decrease in the mean arterial Pao2
and a 5.0-mm Hg increase in the mean arterial carbon dioxide pressure.
Arterial Pao2 determinations on the third, fourth, and fifth postoperative
days returned toward, but remained significantly less than, paired values
obtained before surgery. Patients with hypoxemia after gastrojejunostomy
were significantly older and had significantly lower preoperative arterial
Pao2 measurements than patients who were not hypoxemic after surgery.
Weight, body mass index, and preoperative spirometric measurements did not
distinguish between those patients who did and did not become hypoxemic
postoperatively. We conclude that hypoxemia commonly follows gastric bypass
for morbid obesity, and thus we recommend that all patients undergoing this
procedure be treated with supplemental oxygen for at least the first three
postoperative days.
