Value of routine polysomnography in bariatric surgery

Obstructive sleep apnea (OSA), present in 60-70 % of bariatric surgery patients, is a potentially life-threatening condition when not detected and managed appropriately. The best available method to identify the severity of OSA is polysomnography. However, routine polysomnography measurements have not been accepted as standard modality in bariatric surgery. We report our experience with routine polysomnography in a cohort of patients undergoing bariatric surgery to determine the true prevalence of OSA with respect to the different severity levels as determined by the apnea-hypopnea index (AHI). AHI data were retrospectively collected from all patients who underwent bariatric surgery from 2012 onward, when the performance of preoperative polysomnography became mandatory. Mild, moderate and severe OSA were defined as an AHI 5, 15 and 30/h, respectively. Prevalence and number needed to screen (NNS) were calculated for all OSA severity levels. A total of 1358 patients were included. OSA was detected in 813 (59.9 %; NNS: 2) patients. Moreover, 405 (29.8 %; NNS: 4) patients were diagnosed with an AHI 15/h and 213 (15.7 %; NNS: 7) with severe OSA (AHI 30/h). Extreme AHI thresholds of 60 and 90/h were detected in 79 (5.8 %; NNS: 18) and 17 (1.3 %; NNS: 77) patients, respectively. One-third of the bariatric surgery patients have an AHI 15/h and would benefit from continuous positive airway pressure therapy. In order to increase perioperative safety and avoid the preventable risk of perioperative complications, we recommend mandatory P(S)G prior to bariatric surgery.