Randomized Crossover Study of Neurally Adjusted Ventilatory Assist (NAVA) in Preterm Infants

Study Overview
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Brief Summary
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The purpose of this study is to test the hypothesis that neurally adjusted ventilatory assist (NAVA) will allow to lower the ventilator pressure at equivalent fractions of inspiratory oxygen (FiO2) and partial pressure of CO2 of capillary blood in preterm infants in comparison with currently used standard ventilation (synchronized intermittent mandatory ventilation with pressure-support ventilation, SIMV+PSV).

Detailed Description
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The investigators will apply crossover comparison in preterm infants who received a ventilatory support. In patient whose frequency of mandatory support is under 25, the two ventilatory modes (SIMV+PSV and NAVA) are delivered by the same ventilator (Servo-I; Maquet Critical Care AB, Solna, Sweden) and will set to maintain similar blood gas analysis results. Determination of the type of ventilatory mode used is performed using a cluster randomization. The randomized order of ventilatory mode will be used during total 9 hours; one mode for 4 hours and another mode for 5 hours. To rule out carry-over effects, a 1-hour interval for washout was guaranteed between modes. Recordings will be obtained over a total 8 hours.

Official Title
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Application of Neurally Adjusted Ventilatory Assist (NAVA) in Preterm Infants and Assessment of Its Benefits Compared to Synchronized Intermittent Mandatory Ventilation (SIMV) With Pressure Support (PS)

Conditions
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Infant, Preterm

Intervention / Treatment
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* Procedure: neurally adjusted ventilatory assist (NAVA) ventilator mode


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: preterm infants mechanically ventilated ventilatory set frequency is under 25 with informed consent of their parents Exclusion Criteria: major congenital anomalies patients without self respiratory effort use of sedative or anesthetic drugs grade III or IV intraventricular hemorrhage phrenic nerve palsy or insufficiency

Ages Eligible for Study
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Maximum Age: 12 Weeks

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: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ventilator assist<br> | Procedure: neurally adjusted ventilatory assist (NAVA) ventilator mode<br>* Neurally adjusted ventilatory assist (NAVA) utilizes the electrical activity of the diaphragm (EAdi) to trigger and cycle-off breaths, and therefore presents a means of bypassing the ventilator circuit, and the inherent delays with pneumatic triggering. This is a processed signal, which is not artificially influenced by changes in muscle length, chest wall configuration, and/or lung volume. It represents the summation of muscle motor unit recruitment and/or firing rate, and correlates with phrenic nerve activity. In this mode, the amount of support pressure is coupled with the magnitude of the EAdi. The proportion of support pressure to EAdi (NAVA level) is adjustable.<br>* Other names: Servo-i (Maquet Critical Care AB, Solna, Sweden);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak Inspiratory Pressure | peak inspiratory pressure measured by a ventilator for 4 hours with each ventilator mode | four hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Airway Pressure | mean airway pressure measured by a ventilator for 4 hours with each ventilator mode | four hours | 
| Minute Ventilation | Minute ventilation measured by a ventilator for 4 hours with each ventilator mode | four hours | 
| Expiratory Tidal Volume | Expiratory tidal volume measured by a ventilator for 4 hours with each ventilator mode | four hours | 
| Dynamic Compliance | Dynamic Compliance measured by a ventilator for 4 hours with each ventilator mode | four hours | 
| Work of Breathing | Work of breathing of patients measured by a ventilator for 4 hours with each ventilator mode | four hours | 
| Peak EAdi | Peak electrical activity of the diaphragm | four hours | 
| Fraction of Oxygen | Fraction of oxygen measured by a ventilator for 4 hours with each ventilator mode | four hours | 
| Capillary Blood pH | Capillary blood pH checked immediately after the 4-hour respiratory support with each ventilator mode | four hours | 
| Capillary Blood pCO2 | Capillary blood pCO2 checked immediately after the 4-hour respiratory support with each ventilator mode | four hours | 
| Capillary Blood pO2 | Capillary blood pO2 checked immediately after the 4-hour respiratory support with each ventilator mode | four hours | 
| Capillary Blood HCO3 | Capillary blood HCO3 checked immediately after the 4-hour respiratory support with each ventilator mode | four hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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mechanical ventilation, diaphragm electrical activity, pressure support