Respiratory Failure
Conditions
Keywords
mechanical ventilation, pressure support ventilation, NAVA, PAV, variable ventilation, patient ventilator asynchrony
Brief summary
Experimental animal data suggest that increasing breathing pattern variability in mechanical ventilation could be beneficial. Variable ventilation can be induced through the following modes: Neurally Adjust Ventilatory Assist (NAVA), Proportional Assist Ventilation (PAV) and Variable-Pressure Support Ventilation (V-PSV). These modes have not yet been compared to each other. Pilot observations in our department suggest a feasibility in patients. The objectives of the study are to compare the impact of PSV, NAVA, PAV and V-PSV on the variability of the breathing pattern, patient-ventilator asynchrony, risk of lung overdistension, gas exchange, and repartition of ventilation.
Detailed description
Cross-over, prospective, randomized controlled monocentric trial . Patients on pressure support ventilation will be ventilated with PSV, NAVA, PAV, and V-PSV (in a randomized sequence). In each mode the level of assistance will be set to achieve a similar tidal volume of 6-8 ml/kg. The following data will be measured and recorded: airway flow and pressure, electrical activity of the diaphragm (EAdi), blood gases, electrical impedance tomography, end tidal partial pressure in carbon dioxide (PEtCO2). Will be calculated: the coefficient of variation (CV, standard deviation (SD)/mean) of the peak pressure (Ppeak), EAdi and of the main descriptors of the breathing pattern, the prevalence of the main patient-ventilator asynchronies, the prevalence of tidal volume (VT) \>10ml/kg, ventrodorsal repartition of ventilation and inhomogeneity index, dead space
Interventions
DEVICEPSV, NAVA, PAV, Variable-PSV
Each patient enrolled in the study will be ventilated in all the following modes: PSV, NAVA, PAV and variable PSV
Sponsors
Association pour le Développement et l'Organisation de la Recherche en Pneumologie et sur le Sommeil
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* patient on mechanical ventilation for \>48 h * estimated duration of mechanical ventilation \>24h * hemodynamic stability
Exclusion criteria
* pregnancy * impossibility to insert an EAdi catheter * neuromuscular disease, phrenic nerve lesions
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Coefficient of variation of the maximal inspiratory pressure (Ppeak) | 1 hour | Coefficient of variation (standard deviation/mean) of the maximal inspiratory pressure (Ppeak) |
| Coefficient of variation of the tidal volume (VT) | 1 hour | Coefficient of variation (standard deviation/mean) of the tidal volume (VT) |
| Coefficient of variation of the respiratory rate (RR) | 1 hour | Coefficient of variation (standard deviation/mean) of the respiratory rate (RR) |
| Coefficient of variation of the inspiratory time (Ti) | 1 hour | Coefficient of variation (standard deviation/mean) of the inspiratory time (Ti) |
| Coefficient of variation of the electrical activity of the diaphragm (EAdi) | 1 hour | Coefficient of variation (standard deviation/mean) of the electrical activity of the diaphragm (EAdi) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Patient ventilator asynchrony | 1 hour | asynchrony index (composite outcome, that includes double triggering, auto triggering and ineffective efforts) ) |
| Safety from lung overdistension, assessed by the proportion of tidal volumes (VT) >10 ml/kg | 1 hour | — |
| Gas exchanges | 6 hours | Ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), arterial carbon dioxide pressure (PaCO2) |
| Repartition of ventilation measured by electrical impedance tomography | 6 hours | — |
| Dead space to tidal volume ratio (Vd/Vt) | 6 hours | Vd/Vd, is a ratio between two volumes |
Countries
France
Outcome results
None listed