Inclusion Criteria:  Patient over 18 and under 60 years old. ASA score ≤ 3 Elective bariatric surgery for patient with BMI between 35 and 60 or elective revision of a bariatric surgery for patient with a BMI over 30. Patient with a written consent obtained with accurate information.  Exclusion Criteria:  Patient with risk of aspiration Difficult airway known (Cormack score 3 ou 4). Opioids addiction. Alcoholism Chronic use of Opioids Confirmed Allergy to Propofol or Remifentanil Severe chronic hepatic, kidney or respiratory failure Patient already enrolled in another clinical study interfering with this study.