NHFOV Vs NIPPV Post-extubation in Preterm Neonates

Inclusion Criteria: * Preterm neonates with gestational age between 32 and 36 weeks and on mechanical ventilation ready to be extubated. When the case is ready for extubation , will receive at least one loading dose of caffeine citrate (20 mg/kg/dose) and daily maintenance dose of 5 mg/kg/dose. Criteria for extubation: * Blood gas analysis: PH \> 7.25 and PaCO2 ≤ 60 mmHg. * Airway pressure (Paw) of 7 to 8 cmH2O. * Required fraction of inspired oxygen (FiO2) ≤ 30%. * Sufficient spontaneous breathing by clinical evaluation. Exclusion Criteria: * Full term neonates. * Preterm neonates who will not require intubation. * Preterm neonates with one of the following criteria: birth weight \> 900 gms , major congenital anomalies, upper airway anomalies, neuromuscular diseases, surgical cases, intraventricular hemorrhage grade IV. • Cases that require reintubation after more than 72 hours of extubation.