nCPAP-NAVA-Backup Versus Standard nCPAP for Severe Apnea in Preterm Infants ≤28 Weeks

The goal of this clinical trial is to determine whether nasal continuous positive airway pressure (nCPAP) with neurally adjusted ventilatory assist (NAVA) backup ventilation (nCPAP-NAVA-backup mode) reduces the rate of severe apnea in extremely preterm infants ≤28 weeks' gestation compared with standard nasal continuous positive airway pressure (nCPAP mode). Severe apnea episodes is defined as breathing pause with oxygen levels ( SpO2) below 85% lasting at least 5 seconds and/or heart rate (HR) below 100 beats/minute lasting at least 5 seconds. Each participant will receive both interventions in a randomized order, serving as their own control. The total duration of the intervention will be 24h. Each intervention period will last 12 hours. A washout period of 3 hours will be included between intervention periods to minimize potential carryover effects. Randomized sequences to avoid order effects: * Sequence A: nCPAP mode → nCPAP-NAVA-backup mode * Sequence B: nCPAP-NAVA-backup mode →nCPAP mode

Inclusion Criteria: * Born at ≤28 weeks gestational age * Currently receiving nCPAP mode as part of routine care * Receiving caffeine citrate at a maintenance dose of 10 mg/kg/day * An average of ≥1 severe apnea per hour over a 6-hour period (apnea associated with SpO₂\