Sleep apnea: is routine preoperative screening necessary?

Because perioperative complications of unrecognized obstructive sleep apnea (OSA) can be severe, many bariatric surgery programs routinely screen all patients. However, many obese non-bariatric surgery patients do not get screened. We wanted to evaluate the need for routine preoperative OSA screening.

Morbidly obese patients with a body mass index (BMI) > 40 kg/m(2) undergoing bariatric surgery--all screened for OSA--were compared to morbidly obese orthopedic lower extremity total joint replacements (TJR) patients--not screened for OSA. Cardio-pulmonary complications were recorded.

Eight hundred eighty-two morbidly obese patients undergoing either bariatric (n = 467) or orthopedic TJR surgery (n = 415) were compared. As a result of screening, 119 bariatric surgery patients (25.5 %) were newly diagnosed with OSA, bringing the incidence to 42.8 % (200/467). Orthopedic surgery group had 72 of 415 (17.3 %) patients with pre-existing OSA. The unscreened orthopedic patients had a 6.7 % (23/343) cardiopulmonary complications rate compared to 2.6 % (7/267) for screened bariatric surgery patients. This difference was not statistically significant when adjusted for age and comorbidity (p = 0.3383).

Sleep apnea screening prior to bariatric surgery identifies an additional 25 % of patients as having OSA. In this study, unscreened morbidly obese patients did not have an increased incidence of cardiopulmonary complications after surgery compared to screened patients. Prospective randomized studies should be conducted to definitively assess utility and cost effectiveness of routine OSA screening of all morbidly obese patients undergoing surgery. Preoperative OSA screening may be safely omitted when randomizing patients for such a trial.