The investigators hypothesize that there is a growing trend of the feasibility of HFNC as an alternative to other forms of non-invasive ventilation mechanism to provide continuous distending pressure to preterm infants. However, there remains uncertainty about the efficacy and safety of HFNC in this population.

Our primary outcome is to determine whether postextubation respiratory support via heated humidified high-flow nasal cannula results in a greater proportion of infants younger than 34 weeks gestation being successfully extubated after a period of endotracheal positive pressure ventilation compared with conventional (NCPAP).

The following study will be conducted in the neonatal intensive care unit (NICU) of Gynecology and Obstetric department of Kasr El Aini hospital and neonatal intensive care unit of Military Hospital throughout a time interval of at least 6 months for a minimum of 100 preterm infants.

Infants will be eligible for the study if they born at less than 34 weeks' gestation, required endotracheal intubation and positive pressure ventilation, and considered ready for extubation by the clinical team.

The investigators will assign extubation of preterm ventilated infants (50 preterm infant) in NICU of Military Hospital into HHFNC and extubation of preterm ventilated infants (50 preterm infant) in (NICU) of Gynecology and Obstetric department of Kasr El Aini hospital into NCPAP (50 preterm infant).

Inclusion Criteria:

•Infants born at a gestational age of less than 34 weeks, receiving mechanical ventilation through an endotracheal tube.

Exclusion Criteria:

• Full term neonates or large for gestational age.
• Preterm neonates not supported primarily by invasive ventilation.
• Infants with suspected upper airway obstruction, congenital airway malformations or major cardiopulmonary malformations.

The following study will be conducted in the neonatal intensive care unit (NICU) of Gynecology and Obstetric department of Kasr El Aini hospital and neonatal intensive care unit of Military Hospital throughout a time interval of at least 6 months for a minimum of 100 preterm infants.

Infants will be eligible for the study if they born at less than 34 weeks' gestation, required endotracheal intubation and positive pressure ventilation, and considered ready for extubation by the clinical team.