Efficacy of Volume Ventilation in Patients With Acute Respiratory Failure at Risk of Obstructive Apneas or Obesity Hypoventilation (VONIVOO)

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

Efficacy of Volume Targeted Pressure Support Ventilation vs. Pressure Support 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.

Acute Respiratory Failure, Hypercapnic Respiratory Failure, Respiratory Acidosis, Obesity, Hypoventilation Syndrome, Apnea, Obstructive

non-invasive ventilation, respiratory failure, obese, obesity, Hypoventilation Syndrome, apnea, hypercapnic, acidosis, AVAPS-AE, VONIVOO

The patients are randomized in 2 arms at their admission : S/T mode arm : the patient is ventilated as the standard procedure of the ICU, with settings defined by the pratician. AVAPS-AE mode arm : the pratician sets NIV with a positive expiratory pressure set between 4 and 14 cmH2O, an inspiratory support between 14 and 24 cmH2O and a target tidal volume between 8 and 10 mL/kg of an ideal weight (Size (m) * Size (m) * 23).

NIV will be setup in AVAPS-AE mode, with a Trilogy ventilation device (Respironics, Murrysville, PA). The range of positive expiratory pressure will be set between 4 and 14 cmH2O. The range of inspiratory pressure support will be set between 14 and 24 cmH2. The target tidal volume will be set to achieve 8 to 10 mL/kg of ideal body weight (Size (m) * Size (m) * 23).

NIV will be setup in ST mode, with a Trilogy ventilation device (Respironics, Murrysville, PA). The physician will decide the level of positive expiratory pressure and of pressure support.

Comparison of persistent apneic events on NIV (/h) during the first night (determined with a respiratory polygraph) between S/T mode arm and AVAPS-AE mode arm (determined with an oxymeter)

Comparison of patient-ventilator asynchronisms during NIV (/h) between S/T mode arm and AVAPS-AE mode arm (determined with ventilator datas and a respiratory polygraph)

Comparison of time during NIV with a oxygen saturation below 90% between S/T mode arm and AVAPS-AE mode arm (determined with an oxymeter)

Comparison of NIV confort between S/T mode arm and AVAPS-AE mode arm (NIV confort determined by a visual scale: 0: very comfortable to 10:not comfortable at all)

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