Efficacy of Volume Ventilation in Patients With Acute Respiratory Failure at Risk of Obstructive Apneas or Obesity Hypoventilation
Efficacy of Volume Ventilation in Patients With Acute Respiratory Failure at Risk of Obstructive Apneas or Obesity Hypoventilation
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.
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.
Inclusion Criteria:

 -  Patient of age

 -  Patient benefitting of social security

 -  Informed patient who signed the information note and the research enlighted consent
 form

 -  Admission in respiratory intensive care unit for an acid-hypercapnic exacerbation
 (defined by pH≤ 7,35)

 -  BMI ≥ 30kg/m2

 -  PaCO2 > 6.5 kPa on blood gases at ICU admission

 Exclusion Criteria:

 -  Confirmed COPD with a spirometry (VEMS/CVF < 70%)

 -  Pregnant women, or breast-feeding women

 -  Patient with a judiciary or administrative liberty deprivation

 -  Patients under guardianship

 -  Contraindication to NIV