The spontaneous breathing trial will determine the extubation readiness of the subject.

Subjects will be extubated using usual care, without the use of the spontaneous breathing trial.

The SBT is performed daily on rounds if an infant is on conventional ventilation and meets all predetermined ventilator criteria (set ventilator rate ≤30, peak inspiratory pressure (PIP) delivered on mandatory breaths ≤20 cm H2O, pressure support (PS) ≤8 cm H2O, positive end-expiratory pressure (PEEP) ≤6 cm H2O, inspired fractional oxygen (FiO2) ≤0.40).

During the SBT, the ventilator rate and pressure support are set to zero, and the infant is maintained on continuous positive airway pressure (CPAP) alone via the endotracheal tube. The trial duration is 3 minutes, unless an infant fails before the trial is complete. Failure is defined as bradycardia <100 for >15 seconds or oxygen saturation by pulse oximetry <85% despite a 15% increase in FiO2. If an infant passes the SBT, they are extubated within 3 hours. If an infant fails the SBT, they remain intubated and the daily application of the SBT continues as long as the minimum ventilator criteria are met.

The time from intubation (if >48 hours) to successful extubation (if > 7 days) as evaluated at 34 weeks postmenstrual age (gestational age + chronologic age)

The diagnosis of bronchopulmonary dysplasia will be made at 36 weeks postmenstrual age, using the traditional definition and the NIH Consensus definition.