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

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

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.

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.

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.