Respiratory Pattern During Neurally Adjusted Ventilator Assist (NAVA) in Preterm Infants

Study Overview
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Brief Summary
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This study is to investigate the effect of a wide range of assistance levels on respiratory pattern, breathing variability including tidal volume and peak inspiratory pressure during neurally adjusted ventilatory assist (NAVA) in preterm infants. The investigators also aim to explore whether the effects of NAVA on the electrical activity of diaphragm (Edi) signal amplitude, work of breathing and comfort of preterm infants.

Conditions
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Respiratory Distress Syndrome In Premature Infants, Preterm Infants

Intervention / Treatment
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* Device: Increasing and decreasing NAVA levels with 10-min intervals


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: preterm infants born before 36 weeks of gestational age who received mechanical ventilatory care through the endotracheal tube at least 24 hours for respiratory distress no use of anesthetics or analgetics Exclusion Criteria: with major congenital anomalies (facial, gastrointestinal tract, cardiac, etc) with phrenic nerve palsy or injuries
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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NAVA<br>Seven increasing and decreasing NAVA levels (0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0 and 0.5 cmH2O/uV) will applied to 20 preterm infants each for 10 minutes. | Device: Increasing and decreasing NAVA levels with 10-min intervals<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| maximum Edi | mean of recorded maximum electrical activities in the middle 2 min duration out of the total 10 min period | the middle 2 minutes duration out of the total interval of 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| comfort score | calculated score of premature infant pain profile (PIPP) from the recorded video, heart rates and oxygen saturation | the 5-min point in the total 10-min period | 
| peak inspiratory pressure | mean of recorded peak inspiratory pressures in the middle 2 min duration out of the total 10 min period | the middle 2 minutes duration out of the total interval of 10 minutes | 
| tidal volume | mean of recorded expiratory tidal volumes in the middle 2 min duration out of the total 10 min period | the middle 2 minutes duration out of the total interval of 10 minutes | 
| inspiratory time in excess | mean of calculated excessive inspiratory times from the calculation ((ventilator pressurization time-neural inspiratory time)/neural inspiratory time) from the middle 2 min duration out of the total 10 min period | the middle 2 minutes duration out of the total interval of 10 minutes | 
| electrical time product | mean of calculated electrical time product from the middle 2 min duration out of the total 10 min period | the middle 2 minutes duration out of the total interval of 10 minutes |