Risk assessment of obstructive sleep apnea in a population of patients undergoing ambulatory surgery

The aims of this study were to: (a) assess the prevalence of diagnosed OSA and symptoms of undiagnosed OSA in a cohort of ambulatory surgical patients, and (b) characterize the frequency of postoperative complications in outpatients with a diagnosis of or a propensity to OSA.

Patients presenting for ambulatory surgery completed a self-administered questionnaire. Using a previously validated prediction model, the probability for OSA was determined. Patients with > or = 70% propensities were considered to be at high risk of having the disorder. Relevant perioperative data and complications were tracked and recorded, and differences in median estimated propensities for OSA were considered by these data.

Three-thousand five hundred fifty-three patients 'completed the preoperative survey. A total of 2139 patients had perioperative data and estimated propensity scores. Ninety-four of the 2139 (4.4%) patients gave a self-reported prior diagnosis of OSA. One hundred three (4.8%) patients were found to be at high risk of OSA based on the survey and prediction model. Seventy-five percent of the patients with > 70% propensity for OSA had not yet been diagnosed. There was no association between OSA propensity scores and unplanned hospital admission, however there was an association of increased propensity with difficult intubation, intraoperative use of pressors, and postoperative oxygen saturation in the PACU.

The results of this study suggest that undiagnosed OSA may be relatively common in an ambulatory surgical population. There was no relationship between unplanned hospital admission and diagnosis of or increased risk of OSA. However, there was an association of increased perioperative events requiring additional anesthetic management in patients with a diagnosis of, or with a higher propensity to OSA.