Physiologic Comparison Between NIV-NAVA and PS in Preterm Infants

Study Overview
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Brief Summary
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Neurally adjusted ventilatory assist (NAVA) has been shown to improve patient- ventilator interaction and reduce asynchronies. This is a short-term physiologic comparison between PSV (pressure support ventilation) and NAVA in delivering noninvasive ventilation through a nasal cannula, in premature infants postextubation. Patients will undergo a 30-min crossover trial of noninvasive PSV and NAVA, 15 minutes each. Diaphragm electrical activity (EAdi)and airway pressure (Paw) are recorded to derive neural and mechanical respiratory rate and timing, inspiratory trigger delays time of synchrony between diaphragm contraction and ventilator assistance, and the asynchrony index (AI).

Official Title
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Physiologic Comparison Between Noninvasive Neurally Adjusted Ventilatory Assist (NAVA) and Pressure Support (PS) in Preterm Infants

Conditions
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Noninvasive Neurally Adjusted Ventilatory Assist and Pressure Support in Preterm Infants

Intervention / Treatment
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* Device: noninvasive respiratory support with NAVA mode and PSV


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: preterm infants less than 32 weeks of gestational age intubated more than 48 hours after birth subjected to extubation with minimal ventilator setting (mean airway pressure < 7cmH2O + peak inspiratory pressure < 13 cmH2O + FiO2 < 0.4 + respiratory rate < 35/min) with informed consent from parents Exclusion Criteria: with major congenital anomalies use of sedative or anesthetic drugs hemodynamic instability grade 3 or higher intraventricular hemorrhage phrenic nerve palsy

Ages Eligible for Study
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Minimum Age: 3 Days
Maximum Age: 3 Months

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NAVA-PS<br>noninvasive NAVA first for 15 minutes and then PSV for 15 minutes | Device: noninvasive respiratory support with NAVA mode and PSV<br> <br> |
| Experimental: PS-NAVA<br>noninvasive PSV first for 15 minutes and then NAVA for 15 minutes | Device: noninvasive respiratory support with NAVA mode and PSV<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Trigger Delay | Inspiratory trigger delay could be calculated by the time interval between beginning of the increase of actual diaphragmatic excitation and start of ventilator inspiratory flow of each respiration. The value will be present as a mean of all inspiratory trigger delay measurements of all respiration during last 5 minutes of each 15 minutes trial. | last 5-min of each 15-min trial | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ti_excess (Inspiratory Time in Excess) | Ti_excess = (VPT-NIT)/NIT VPT: ventilator pressurization time (VPT) between beginning and end of inspiratory flow NIT: neural inspiratory time (NIT) between beginning of the increase in the diaphragmatic excitation and its maximal value | last 5-min of each 15-min trial | 
| Minute Ventilation Volume | inspiratory tidal volume / respiratory rate | last 5-min of each 15-min trial | 
| Peak Inspiratory Pressure |  | last 5-min of each 15-min trial | 
| Pneumatic Respiratory Rate |  | last 5-min of each 15-min trial | 
| Maximum EAdi |  | last 5-min of each 15-min trial | 
| Swing EAdi |  | last 5-min of each 15-min trial | 
| Leakage | [TVi (inspiratory tidal volume) - TVe (expiratory tidal volume)]/TVi (inspiratory tidal volume) | last 5-min of each 15-min trial | 
| All Asynchrony Events |  | last 5-min of each 15-min trial | 
| Asynchrony Index | total number of each event per minute ineffective efforts: presence of a characteristic EAdi (electrical activity of diaphragm) activity not followed by a ventilator delivered pressurization auto-triggering: a cycle delivered by the ventilator without EAdi signal premature cycling delayed cycling: VPT > NIT x2 double triggering Asynchrony index = [(1)+(2)+(3)+(4)+(5)]/[(1)+pneumatic respiratory rate] x100 | last 5-min of each 15-min trial | 
| SpO2 | transcutaneous peripheral saturation of oxygen by pulse oximeter | last 5-min of each 15-min trial | 
| Heart Rate |  | last 5-min of each 15-min trial | 
| Blood Pressure | systolic, diastolic and mean blood pressure measured by non-invasive cuff | last 5-min of each 15-min trial | 
| Respiratory Rate |  | last 5-min of each 15-min trial | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Preterm infant less than 32 weeks of gestation age, intubated more than 48 hours after birth, postextubation