NAVASET: Nava Level Titration Using Comfort Scales

Study Overview
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Brief Summary
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Determining the optimal Neurally Adjusted Ventilatory Assist (NAVA) level remains challenging, and several methods have been suggested. However none of them seems easily utilisable. Thus the investigators propose to test a way of NAVA level titration according to ventilator comfort.

Detailed Description
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Physiological comparison of different levels of ventilator assistance during Neurally Adjusted Ventilatory Assist (NAVA) to evaluate the effect of these on tidal volume, inspiratoy activity, comfort scales. We propose to evaluate the ability to guide the titration according the patient's comfort scale. The intensity of the breathing sensations will be evaluated using the labeled visual analog scale (Banzett Scale).

Official Title
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Neurally Adjusted Ventilatory Assist (NAVA) Levels Titration During Weaning Using Ventilatory Comfort Scales: a Physiological Evaluation

Conditions
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Acute Respiratory Failure

Intervention / Treatment
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* Device: PSV - pressure support ventilation
* Device: Neurally Adjusted Ventilatory Assist


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 years Hospitalized in intensive care unit for an acute respiratory failure Intubated or tracheotomized and mechanically ventilated RASS score: 0;-2 Weaning period Exclusion Criteria: Hemodynamic instability Absence of consent Contraindication of nasogastric catheter insertion

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Pressure Support Ventilation<br>Device: PSV - pressure support ventilation | Device: PSV - pressure support ventilation<br>* Gold standard partial ventilator support: Pressure Support Ventilation performed with Servo-i® ventilator (MAQUET,Critical Care, Sweden). Pressure support ventilator assistance to obtain a tidal volume of 6-8 ml/kg of ideal body weight.<br>|
| Active Comparator: Neurally Adjusted Ventilatory Assist<br>Device: Partial ventilator support with partial ventilation mode (NAVA) | Device: Neurally Adjusted Ventilatory Assist<br>* Partial ventilator support partial ventilation mode (NAVA) performed with Servo-i® ventilator (Maquet,Critical Care, Sweden). Different levels of neurally adjusted ventilatory assist are tested. Stepwise implementation of the NAVA level (steps of 25% ), returning to the  optimal  level between each evaluation (PSV 100%, NAVA 100%, 75%, 50%, 125%, 150%).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of ventilatory comfort with the physiological parameters when varying the levels of pressure support and Neurally Adjusted Ventilatory Assist (NAVA) | To prove the feasibility of neurally adjusted ventilatory assist (NAVA) level titration according to the ventilatory comfort felt by the patient. The ventilatory comfort will be evaluated using the labeled visual analog scale (Banzett scale). | 24hr | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Efficiency | The efficiency will be evaluated by using minute ventilation | 24hr | 
| Efficiency | The efficiency will be evaluated using arterial PCO2. | 24hr | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Mechanical ventilation, Acute respiratory failure, Weaning, Pressure support ventilation, Neurally adjusted ventilatory assist