How Relevant Is Pre-operative Obstructive Sleep Apnoea in the Asymptomatic Bariatric Surgery Patient?

INTRODUCTION: The American Academy of Sleep Medicine recommends patients attending for bariatric surgery (BS) to be evaluated for obstructive sleep apnoea (OSA) as untreated OSA is associated with a greater risk of post-operative complications. Not all bariatric patients have symptoms of OSA and their phenotype may be at less risk than the typical sleep clinic phenotype. Therefore, all patients may not require pre-operative sleep studies. This study aimed to establish whether screened and unscreened BS patients are at increased risk of post-operative complications. METHODS: A retrospective review of BS patients at a single centre, June 2008-May 2017. Demographic data, sleep study outcomes, post-operative complications, length of stay (LOS), intensive care unit (ICU) admission, and readmission rates were reviewed. RESULTS: A total of 510 patients underwent gastric bypass, sleeve gastrectomy, or gastric banding. 385/510 (75.5%) were female. Mean age was 46 ± 11.27 years, mean BMI was 49 kg/m(2) ± 7.42. OSA was diagnosed in 300/510 (58.8%) and normal sleep in 57/510 (11.2%). OSA was not associated with increased post-operative complications. No significant difference between screened and unscreened patients for the development of post-operative pulmonary or cardiac complications, (p = 0.607, p = 0.827, respectively). Increasing age was a predictor for pulmonary (p = 0.011) and cardiac (p = 0.018) complications. CONCLUSION: OSA is very prevalent in morbidly obese patients. The lack of association between patients diagnosed with OSA and unscreened patients, and post-operative complications suggests that not all patients require pre-operative sleep studies. Further studies may help identify which patients can safely avoid OSA screening.