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Original Investigation
May 2017

Effect of Incentive Spirometry on Postoperative Hypoxemia and Pulmonary Complications After Bariatric SurgeryA Randomized Clinical Trial

Author Affiliations
  • 1Department of General Surgery, Lahey Hospital and Medical Center, Burlington, Massachusetts
JAMA Surg. 2017;152(5):422-428. doi:10.1001/jamasurg.2016.4981
Key Points

Question  What is the effect of postoperative incentive spirometry on hypoxemia, oxygen saturation, and pulmonary complications after bariatric surgery?

Findings  In this randomized noninferiority clinical trial of 224 patients undergoing bariatric surgery, no significant difference in the frequency of postoperative hypoxemia was found between patients who used incentive spirometry after surgery and those who did not. In addition, oxygen saturation levels and 30-day postoperative pulmonary complication rates did not differ between groups.

Meaning  In its current implementation, use of postoperative incentive spirometry after bariatric surgery does not appear to decrease hypoxemia or postoperative pulmonary complications.


Importance  The combination of obesity and foregut surgery puts patients undergoing bariatric surgery at high risk for postoperative pulmonary complications. Postoperative incentive spirometry (IS) is a ubiquitous practice; however, little evidence exists on its effectiveness.

Objective  To determine the effect of postoperative IS on hypoxemia, arterial oxygen saturation (Sao2) level, and pulmonary complications after bariatric surgery.

Design, Setting, and Participants  A randomized noninferiority clinical trial enrolled patients undergoing bariatric surgery from May 1, 2015, to June 30, 2016. Patients were randomized to postoperative IS (control group) or clinical observation (test group) at a single-center tertiary referral teaching hospital. Analysis was based on the evaluable population.

Interventions  The controls received the standard of care with IS use 10 times every hour while awake. The test group did not receive an IS device or these orders.

Main Outcomes and Measures  The primary outcome was frequency of hypoxemia, defined as an Sao2 level of less than 92% without supplementation at 6, 12, and 24 postoperative hours. Secondary outcomes were Sao2 levels at these times and the rate of 30-day postoperative pulmonary complications.

Results  A total of 224 patients (50 men [22.3%] and 174 women [77.7%]; mean [SD] age, 45.6 [11.8] years) were enrolled, and 112 were randomized for each group. Baseline characteristics of the groups were similar. No significant differences in frequency of postoperative hypoxemia between the control and test groups were found at 6 (11.9% vs 10.4%; P = .72), 12 (5.4% vs 8.2%; P = .40), or 24 (3.7% vs 4.6%; P = .73) postoperative hours. No significant differences were observed in mean (SD) Sao2 level between the control and test groups at 6 (94.9% [3.2%] vs 94.9% [2.9%]; P = .99), 12 (95.4% [2.2%] vs 95.1% [2.5%]; P = .40), or 24 (95.7% [2.4%] vs 95.6% [2.4%]; P = .69) postoperative hours. Rates of 30-day postoperative pulmonary complications did not differ between groups (8 patients [7.1%] in the control group vs 4 [3.6%] in the test group; P = .24).

Conclusions and Relevance  Postoperative IS did not demonstrate any effect on postoperative hypoxemia, Sao2 level, or postoperative pulmonary complications. Based on these findings, the routine use of IS is not recommended after bariatric surgery in its current implementation.

Trial Registration  clinicaltrials.gov Identifier: NCT02431455