Physiological Changes With High-Flow Nasal Cannula

Study Overview
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Brief Summary
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To measure changes in physiologic parameters in extremely low birthweight (ELBW) infants on high-flow nasal cannula compared to nasal continuous positive airway pressure (nCPAP).

Detailed Description
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After informed consent is obtained, eligible infants who are stable on nCPAP therapy of 5-7 cm H20 achieved with a ventilator, an underwater bubble system, or a variable-flow device will be enrolled. All subjects will have physiologic data and electrical impedance tomography collected at: Baseline nCPAP for 15 minutes Upon transition to high flow nasal cannula at 8 LPM for 6 hours. Data collection is obtained after infant is calm for 15 minutes at the beginning and end of this 6 hour period Then upon return to baseline NCPAP for a final 15 minutes of data collection.

Official Title
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Physiological Changes With High-Flow Nasal Cannula Compared to Nasal CPAP in Extremely Low Birth Weight Infants

Conditions
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Respiratory Distress Syndrome in Premature Infant

Intervention / Treatment
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* Procedure: High flow nasal cannula
* Procedure: Nasal CPAP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 23 to 28+6 weeks gestational age at birth Corrected gestational age less than or equal to 30 weeks Over 72 hours of life Stable on Nasal CPAP of 5-7cm H20 Hemodynamically stable Tolerating routine handling Nares size appropriate for Fisher & Paykel Optiflow Jr 2 HFNC size XS or small Successfully extubated for 12 hours after administration of surfactant Caffeine Citrate at a maintenance dose of 5 to 10 mg /kg Transcutaneous monitoring in place Stable blood gas (pH>/= 7.25 and PaCO2 <60 mmHg torr) Exclusion Criteria: Prior pneumothorax or evidence of pulmonary interstitial emphysema. Prior or current pulmonary hemorrhage Congenital airway malformations Major cardiopulmonary malformations Congenital Diaphragmatic hernia or untreated bowel obstruction Poor respiratory drive unresponsive to CPAP therapy Requirement of a nCPAP of >8 cmH20 or FiO2 > 0.3 to maintain oxygen saturations between 90-95 percent. Receiving positive pressure breaths or SIPAP on prongs Conflicting clinical trial Clinically unstable per physician discretion

Ages Eligible for Study
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Minimum Age: 23 Weeks
Maximum Age: 29 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: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Nasal CPAP - Period 1<br>Eligible infants stable on high flow nasal cannula (nCPAP) therapy of 5-7 cm H20 achieved with a ventilator, an underwater bubble system, or a variable-flow device will be enrolled. A data acquisition cart will be placed at the subject's bedside to collect hemodynamic and respiratory parameters measured including: Heart rate (HR), blood pressure (BP), respiratory rate (RR), fraction of inspired oxygen (FiO2), transcutaneous carbon dioxide (TcCO2), and peripheral oxygen saturation (SpO2) via bedside monitoring devices. A neonatal chest belt, sized to the infant's chest circumference (nipple level) using warmed ultrasound gel applied to the belt beforehand, will collect regional lung volume measurements using electrical impedance tomography (EIT). Subject video recording will capture apnea events and the interventions used to resolve them such as positive pressure ventilation, repositioning, or stimulation. Data will be collected for 15 minutes on nCPAP. | Procedure: Nasal CPAP<br>* Nasal continuous positive airway pressure of 5-7 cm/H20 delivered using Ventilator or bubble cpap device through short nasal prongs or a nasal face mask.<br>|
| Active Comparator: High Flow Nasal Cannula (HFNC) - Period 2 & 3<br>Respiratory support will be crossed over to a HFNC Optiflow Jr 2 (Fisher & Paykel Healthcare, Auckland, New Zealand) at a flow rate of 8 LPM. The size of the nasal cannula will be determined according to the manufacturer's instructions in order to maintain a leak at the nares. Identical data collection will occur for two 15 minute periods on HFNC, at the beginning and end of the six hour Study period. | Procedure: High flow nasal cannula<br>* 8 liters per minute of blended oxygen through Fisher Paykel Optiflow Jr 2 nasal prongs.<br>|
| Active Comparator: Nasal CPAP - Period 4<br>After 6 hours of HFNC of 8 LPM, or sooner if the infant meets failure criteria, the infant will then be crossed back to the nCPAP device and at the settings previously utilized in Study Period 1. The infant will remain on the nCPAP device with identical data collection for 15 minutes. The total duration of the study and data collection will be 8 hours. The infant's body position will be similar for each lung volume measurement during the study periods. | Procedure: Nasal CPAP<br>* Nasal continuous positive airway pressure of 5-7 cm/H20 delivered using Ventilator or bubble cpap device through short nasal prongs or a nasal face mask.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| % Unventilated Lung | Atelectasis will be calculated using the percentage of the lung fields that are not engaged in tidal volume.(VT) | Through study completion, an average of 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric Center of Ventilation (CoV) | numeric value that describes the geographic point within the thorax that represents the statistical center of VT | Through study completion, an average of 30 days | 
| End-expiratory lung volume | % of total VT within 8 lung regions, relative change in uncalibrated aeration | Through study completion, an average of 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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high flow nasal cannula, nasal cpap