Studies in the medical literature underline the importance of monitoring the pressure of the balloon and the relationship with the incidence cited on the pain and discomfort related to the gesture of the upper airways. There are no formal recommendations in the literature, the French Society of Anesthesia and Resuscitation (SFAR) recommends monitoring the pressure intraoperatively except after intubation. It would be interesting to see and thus make an inventory of the practices, to reiterate the importance of monitoring throughout the gesture and at the change of position to avoid either micro-inhalation linked to under pressure of the balloon or overpressure which causes a potential risk of tracheal injury.

Inclusion criteria:

• Elderly patient ≥ 18 years old
• Patient who has a scheduled spine intervention in the prone position from January 1, 2023 to April 30, 2023
• Intubated patient with endotracheal tube under mechanical ventilation
• Sedation and curarization
• ASA 1, 2 and 3
• Duration of surgery > 1 hour
• Subject not objecting to the reuse of their data for the purposes of this research.

Exclusion criteria:

• Subject who expressed their opposition to participating in the study
• ASA 4, difficult intubation and emergency
• Lung pathologies (asthma, COPD, tracheomalacia)
• Severe heart failure
• Septic, cardiogenic or volume shock
• Morbid obesity (BMI >40)

Adult patient who has a scheduled spine intervention in the prone position from January 1, 2023 to April 30, 2023.