Intubation of Obese Patients in the Operating Room With or Without Face Mask Ventilation

Inclusion criteria: * patient requiring general anesthesia with intubation for surgery or scheduled endoscopic procedures * age \> 18 years * with a BMI superior or equal to 35kg.m-² * patient having signed an informed consent Non-inclusion criteria: * ambient air saturation \<90% * urgent surgery \< 24 hours * cardio-thoracic surgery * mask ventilation not possible (e.g. ATCD, cervical irradiation, fixed mandible) * formal contraindication to mask ventilation (e.g. occlusive syndrome, non fasting patient, symptomatic gastroesophageal reflux untreated or persistent under treatment) * wish of the operator for high flow oxygen preoxygenation * wish of an intubation without curare by the operator * pregnant or breast-feeding women * protected adults (guardianship, curatorship or safeguard of justice) * participation in another randomized clinical research study concerning preoxygenation and relevant to the primary endpoint * absence of affiliation to the French social security system