[Obstructive sleep-apnoea syndrome in adult and its perioperative management]

Obstructive sleep apnoea (OSA) syndrome in adult is defined as an Apnoea-Hypopnoea Index (AHI) of 5 or more per hour of sleep in a context of excessive daytime sleepiness and snoring. OSA is considered as mild with an AHI of 5-15, moderate with an AHI of 15-30, and severe with an AHI greater than 30. OSA is a highly prevalent disease since it should affect 7-15% of the middle-aged population, but most patients are not yet diagnosed for OSA. Middle age, male gender, obesity and arterial hypertension are main risk factors for OSA in adults. OSA patients are exposed to higher neurological and cardiovascular morbidity, including stroke, depression, hypertension, coronary artery disease, heart failure, arrhythmias. Because OSA may lead to life-threatening problems if undiagnosed, anaesthesiologists should be aware of their screening role in the preoperative period. In that way, the STOP-BANG questionnaire is a well-adapted instrument to screen patients for OSA during the preoperative visit. OSA patients are exposed to higher preoperative morbidity in relation with OSA severity, particularly difficult manual ventilation with mask, difficult tracheal intubation and postoperative upper airway obstruction. The unknown diagnosis of OSA is one major contributor to facilitate the occurrence of those events. In the postoperative period, early resuming continuous positive airway pressure and installing the OSA patient in a nonsupine position could be effective in preventing pharyngeal obstruction. Considering the timing of postoperative complications, a careful monitoring in the post-anesthesia care unit for three hours is an appropriate strategy for a majority of OSA patients. Alternatives to opioids should be promoted for postoperative pain control.