Comparison of Proportional Assist Ventilation And Neurally Adjusted Ventilator Assist

Breathing Pattern Variability, Respiratory Discomfort and Work of Breathing in Proportional Assist Ventilation And Neurally Adjusted Ventilator Assist

In spontaneously breathing mechanically ventilated patients, the adequacy between the patient's demand and the level of respiratory support delivered by the ventilator is a major clinical issue. Neurally adjusted ventilator assist (NAVA) and proportional assist ventilation (PAV) have been developed to adapt the level of assistance to the patient's demand. These two modes have been compared to pressure support ventilation (PSV) but have not been compared to each other.

Inclusion Criteria:

• Intubated patients.
• Mechanical ventilation for a respiratory reason.
• Expected duration of Mechanical ventilation > 48 hrs.
• Spontaneous breathing.
• Sedations stopped for more than 24 hours.

Exclusion Criteria:

• - Main contra indications to NAVA: gastro-oesophageal surgery in the previous 12 months, oesophageal obstruction, gastro-esophageal bleeding in the previous 30 days, history of esophageal varices, facial trauma or surgery, neuromuscular diseases, individuals with known or suspected phrenic nerve dysfunction.
• Main contra indications to PAV: airway leak, body weight <25 kg, neuromuscular diseases.
• Hemodynamic instability defined as the current administration of vasopressors or inotropic drugs.
• Severe hypoxemia defined as PaO2/FiO2 ratio <200.
• Decision to withhold life-sustaining treatment.
• Pregnant women.
• Minors < 18 years.