Non-invasive nocturnal ventilation is an effective treatment for chronic respiratory failure, whether due to obstructive (COPD), restrictive or neuromuscular causes, notably for patients in the last two categories for whom it significantly prolongs life expectancy. Overall, the treatment is well tolerated, its principal adverse effects being discomfort related to the mask.

In certain patients, morning dyspnoea when the mask is removed has been described. This is disabling as it limits everyday activities for at least 30 minutes, and defines deventilation syndrome. The pathophysiology of this syndrome is uncertain, notably the roles of hyperinflation, patient/ventilator asynchrony, or the sudden increase in diaphragmatic work after a night of rest.

The aim of this study is to investigate the prevalence of and factors associated with reventilation syndrome (DS) in a population of patients with ventilation whatever the reason, in a stable state, and followed by the medical devices department of Dijon CHU, so as to better understand the mechanisms. Patients with DS will subsequently be invited to participate in a therapeutic trial.

Inclusion Criteria:

• patients over 18 years old
• ventilation for whatever reason
• in the ST mode
• not in life support
• at more than 1 month after the last episode of respiratory decompensation

Exclusion Criteria:

• guardianship
• inability to understand instructions and provide consent
• uncontrolled psychiatric disease

population of patients with ventilation whatever the reason, in a stable state, and followed by the medical devices department of Dijon CHU