Obstructive sleep-related breathing disorders in patients evaluated for bariatric surgery

Obesity is a well known risk factor for obstructive sleep apnea (OSA). Medical therapy is not effective for morbid obesity. Bariatric surgery is therefore a reasonable option for weight reduction for patients with clinically severe obesity. Unrecognized OSA, especially in those patients receiving abdominal surgery, has influenced perioperative morbidity and morality. The incidence of OSA for patients being evaluated for bariatric surgery has not been previously defined.

40 consecutive patients being evaluated for bariatric surgery were examined with a history, physical examination and laboratory data. Polysomnography (PSG) was conducted in all patients regardless of symptoms.

An obstructive sleep-related breathing disorder (OSRBD) was present in 88% of the patients. OSA was present in 29 of 41 (71%) and upper airway resistance syndrome (UARS) in 7 of 41 (17%). The mean low oxygen desaturation was 84% and continuous positive airway pressure (CPAP) was 10 cm H2O pressure. The majority of the patients were women and mean BMI was 47 kg/m2. Patient characteristics failed to predict the severity of OSRBD.

This population of clinically severe obese patients being evaluated for bariatric surgery had an 88% incidence of an OSRBD, 71% with OSA. Appropriate therapy with CPAP perioperatively would theoretically prevent hypoxic complications associated with OSRBD. Providers should have a low threshold for ordering a PSG as part of the preoperative evaluation for bariatric surgery. Empiric CPAP at 10 cm H2O should be considered for those patients who cannot complete a PSG before surgery.