Study of the Effects of CPAP and HHHFNC on Diaphragmatic Dimensions in Preterm Infants

Study Overview
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Brief Summary
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This is a prospective, randomized crossover study to recognize the effects of nasal continuous positive airway pressure (CPAP) versus heated humidified high flow nasal cannula (HHHFNC) on diaphragmatic dimensions and excursion (evaluated by ultrasonography) in preterm infants.

Detailed Description
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Preterm infants will be recruited consecutively from NICU of Mansoura University Children's Hospital. They will be randomized in two groups; one group will start on nasal CPAP (Fisher & Paykel Healthcare, Auckland, New Z ealand) (Pressure 5 cmH2O) for 60 minutes and then will be switched to HHHFNC (Fisher & Paykel Healthcare, Auckland, New Z ealand) (flow of 4 l/m) for another 60 minutes. The other group will start on HHHFNC and then switched to nasal CPAP. After the 2 h study period (2×60 minutes epochs) further respiratory support will be at the discretion of the clinical team. Ultrasonographic assessment of diaphragmatic dimensions and excursion will be analyzed in different respiratory cycles and the average of 3 cycles will be calculated at the end of the 60 minutes periods on nasal CPAP and HHHFNC.

Official Title
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Comparative Study of the Effects of Continuous Positive Airway Pressure and Heated, Humidified High Flow Nasal Cannula on Diaphragmatic Dimensions in Preterm Infants

Conditions
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Respirtory Distress

Intervention / Treatment
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* Device: CPAP first (Fisher & Paykel Healthcare)
* Device: HHHFNC first (Fisher & Paykel Healthcare)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Preterm infants < 37 weeks. Stable on nasal continuous positive airway pressure (CPAP) for at least 24 hours. On less than 35% oxygen. Exclusion Criteria: Congenital and acquired problems of the gastrointestinal tract as necrotizing enterocolitis, esophageal perforation and tracheoesophageal fistula. Phrenic nerve injury and/or diaphragm paralysis Congenital/acquired neurological deficit and/or seizures Hemodynamic instability Congenital heart disease (including symptomatic patent ductus arteriosus) Undergoing treatment for sepsis or pneumonia. Use of muscle relaxants, narcotic analgesics, or gastric motility agents. Congenital anomalies of respiratory tract. Infants requiring more than 35% oxygen. Infants with facial anomalies. Infants with pneumothorax and/or pneumomediatinum. Infants in the immediate postoperative period. Infants with significant gastric residues and vomiting.

Ages Eligible for Study
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Maximum Age: 1 Month

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 |
| --- | --- |
| Active Comparator: CPAP first<br>Infant will be given nasal CPAP for 60 minutes and then put on HHHFNC for another 60 minutes. Ultrasonographic assessment of diaphragmatic dimensions and excursion will be done at the end of the 60 minute periods on nasal CPAP and HHHFNC. After the 2 h study period (2×60 minutes epochs) further respiratory support will be at the discretion of the clinical team | Device: CPAP first (Fisher & Paykel Healthcare)<br>* Infants will start on nasal CPAP for 60 minutes and then switched to HHHFNC for anther 60 minutes. Ultrasonographic assessment of diaphragmatic dimensions and excursion will be done at the end of each 60 minute epochs.<br>|
| Active Comparator: HHHFNC first<br>Infant will be given HHHFNC for 60 minutes and then switched to nasal CPAP for another 30 minutes. Ultrasonographic assessment of diaphragmatic dimensions and excursion will be done at the end of the 60 minute periods on HHHFNC and nasal CPAP. After the 2 h study period (2×60 minutes epochs) further respiratory support will be at the discretion of the clinical team | Device: HHHFNC first (Fisher & Paykel Healthcare)<br>* Infants will start on HHHFNC for 60 minutes and then switched to nasal CPAP for anther 60 minutes. Ultrasonographic assessment of diaphragmatic dimensions and excursion will be done at the end of each 60 minute epochs.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diaphragmatic dimensions (inspiratory diaphragmatic thickness, expiratory diaphragmatic thickness and delta diaphragmatic thickness) | Ultrasonographic assessment of (inspiratory diaphragmatic thickness, expiratory diaphragmatic thickness and delta diaphragmatic thickness will be assessed at the end of each 60 minutes epoch on nasal CPAP. Diaphragm thickness will be measured as the perpendicular distance between the pleural and peritoneal reflections. All measurements will be performed during quiet breathing. Several respiratory cycles will be recorded, and measurements will be averaged from at least three different cycles. | at the end of each 60 minutes epoch on nasal CPAP | 
| Right and left diaphragmatic excursion | Ultrasonographic assessment of right and left diaphragmatic excursion will be assessed at the end of each 60 minutes epoch on nasal CPAP. The displacements of the liver and spleen will be monitored in real-time. Using M-mode ultrasonography, with the probe fixed on the chest wall during respiration, ultrasonographic image of will be frozen and a mark for measurement will be placed on the image at the location of the most caudal margin of the liver or spleen at the end of expiration, and a second mark will be placed on the new location of the most caudal margin of the liver or spleen at the end of inspiration. The distance between the two marks will be then measured and defined as the displacement of the liver or the spleen (right or left diaphragmatic excursion). Several respiratory cycles will be recorded, and measurements will be averaged from at least three different cycles. | at the end of each 60 minute epoch on CPAP | 
| Diaphragmatic dimensions (inspiratory diaphragmatic thickness, expiratory diaphragmatic thickness and delta diaphragmatic thickness) | Ultrasonographic assessment of (inspiratory diaphragmatic thickness, expiratory diaphragmatic thickness and delta diaphragmatic thickness will be assessed at the end of each 60 minutes epoch on HHHFNC. Diaphragm thickness will be measured as the perpendicular distance between the pleural and peritoneal reflections. All measurements will be performed during quiet breathing. Several respiratory cycles will be recorded, and measurements will be averaged from at least three different cycles. | at the end of each 60 minutes epochs on HHHNC | 
| Right and left diaphragmatic excursion | Ultrasonographic assessment of right and left diaphragmatic excursion will be assessed at the end of each 60 minutes epoch on HHHFNC. The displacements of the liver and spleen will be monitored in real-time. Using M-mode ultrasonography, with the probe fixed on the chest wall during respiration, ultrasonographic image of will be frozen and a mark for measurement will be placed on the image at the location of the most caudal margin of the liver or spleen at the end of expiration, and a second mark will be placed on the new location of the most caudal margin of the liver or spleen at the end of inspiration. The distance between the two marks will be then measured and defined as the displacement of the liver or the spleen (right or left diaphragmatic excursion). Several respiratory cycles will be recorded, and measurements will be averaged from at least three different cycles. | at the end of each 60 minutes epochs on HHHNC | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory rate | Respiratory rate will be assessed at the end of each 60 minutes epoch on CPAP or HHHFNC | At the end of each 60 minutes epochs on CPAP and HHHFNC | 
| Heart rate | Heart rate will be assessed at the end of each 60 minutes epoch on CPAP or HHHFNC | At the end of each 60 minutes epochs on CPAP and HHHFNC | 
| Spo2 | Oxygen saturation by pulse oximetry (SpO2) will be assessed at the end of each 60 minutes epoch on CPAP or HHHFNC | At the end of each 60 minutes epochs on CPAP and HHHFNC | 
| Number of apneas | Number of apneas will be recorded during the 60 minutes epoch on CPAP or HHHFNC | during the 60 minutes epochs on CPAP and HHHFNC |