The presence of an obstructive sleep apnea-hypopnea syndrome (OSAHS) is a perfectly identified cardiovascular and metabolic risk factor responsible for excess mortality in patients with severe OSAHS, while life expectancy, when the SAHOS is treated by continuous positive airway pressure (CPAP) is close to that of the general population. It also represents a factor of excess mortality, little known and poorly explored, in relation to morbidity and mortality occurring during the perioperative period accompanying any general anesthesia.

Inclusion Criteria:

• Patients over 18 years old and naive to any treatment with obstructive sleep apnea-hypopnea syndrome,
• Patients at high risk of obstructive sleep apnea-hypopnea syndrome (STOP BANG ≥ 3),
• Patients scheduled for major abdominal surgery (all intraperitoneal surgeries excluding vesicles, eventrations and hernias, all aortic surgeries excluding endovascular surgeries) within a minimum of 10 days,
• It is possible to integrate the explanations concerning the realization of the ApneaLink ™ Air in autonomy and to ensure its restitution under 24-48h,

Exclusion Criteria:

• Patients with obstructive sleep apnea-hypopnea syndrome diagnosed before surgery,
• Patients with heart failure (NYHA> II),
• Patients with moderate to severe COPD
• Patients participating in a clinical trial,

Patients without known obstructive sleep apnea-hypopnea syndrome, presenting at anesthesia consultation for visceral surgery to be performed at least within 10 days.