Sleep apnea syndrome is significantly underdiagnosed in bariatric surgical patients

Devastating morbidity and mortality can result when patients with undiagnosed sleep apnea syndrome (SAS) undergo bariatric surgery. We evaluated the prevalence of SAS and its rate of nondiagnosis in bariatric patients at a university hospital.

The demographic, anthropomorphic, and co-morbidity data were collected from 1368 patients evaluated for bariatric surgery. All patients were screened for symptoms of SAS, and symptomatic patients were evaluated with polysomnography.

At the time of this report, 834 patients (61%) had completed the preoperative evaluation. Of these patients, 210 (25%) presented with previously diagnosed SAS. An additional 174 patients (21%) exhibited symptoms of SAS and underwent polysomnography. Most patients tested (127, 73%) had SAS that required treatment, 11 patients (6%) had mild SAS not requiring treatment, and 36 (21%) tested negative for SAS. Thus, symptom screening for SAS had a positive predictive value of 79% for predicting the presence of SAS and 73% for identifying patients who required SAS treatment. The patients with SAS tended to be older and male and have a greater body mass index (P < .05).

Overall, SAS that required treatment with an oral appliance was prevalent (40%) in patients who presented for bariatric surgery. However, many of these patients with significant SAS (38%) were previously undiagnosed, despite exhibiting clear symptoms of the disease. Symptom screening appears to be effective in identifying patients who should be evaluated by polysomnography. To avoid the potential perils of undiagnosed SAS during the perioperative period, patients who undergo bariatric surgery should be screened, tested, and treated for this co-morbidity.