So far, in respiratory intensive care units, the usual treatment of patients with acute hypercapnic respiratory failure with acidosis is non-invasive ventilation set with a pressure support mode (S/T or VS/AI mode depending on the ventilator manufacturer).~AVAPS-AE mode is a volume targeted pressure support mode with an automatic PEP. With the forced oscillations method, the ventilator is able to detect the obstruction and the resistances of upper airways.~It allows the ventilator to change its pressure settings to keep the targeted volume and avoid apneas and hypoventilation.~That is why in patients with a BMI > 30 kg/m², at risk of obesity hypoventilation syndrom or obstructive apneas, this ventilation mode may be interesting.~AVAPS-AE has been evaluated in the home ventilation showing it is as efficient as S/T mode in controlling PaCO2.~However it has never been compared to S/T mode in acute respiratory failure care.
This study compares a volume targeted pressure support non-invasive ventilation with an automatic PEP regulation (AVAPS-AE mode) to a pressure support non-invasive ventilation (S/T mode) in patients with acute hypercapnic respiratory failure with acidosis. This study focuses on patients at risk of obstructive apneas or obesity-hypoventilation syndrom (BMI≥30 kg/m²). Half of participants (33 patients) will receive non invasive ventilation with AVAPS-AE mode, the other half will receive non-invasive ventilation with S/T mode.