Mask versus nasal prong leak and intermittent hypoxia during continuous positive airway pressure in very preterm infants

Background: Nasal continuous positive airway pressure (NCPAP) can be applied via binasal prongs or nasal masks; both may be associated with air leak and intermittent hypoxia. We investigated whether the latter is more frequent with nasal masks or prongs.

Methods: Continuous 24 hours recordings of inspired oxygen fraction (FiO₂), pulse rate, respiratory rate, pulse oximeter saturation (SpO₂) and CPAP level were made in preterm infants with respiratory insufficiency (n=20) managed on CPAP in the NICU at the Royal Hobart Hospital. As part of routine care, nasal interfaces were alternated 4-hourly between mask and prongs. In each recording, the first two segments containing at least 3 hours of artefact-free signal for each interface were selected. Recordings were analysed for episodes with hypoxaemia (SpO₂ <80% for ≥10 s) and bradycardia (pulse rate <80/min for ≥4 s) and for episodes of pressure loss at the nasal interface. Data were compared using Wilcoxon-matched pairs test and are reported as median (IQR).

Results: Infants had a gestational age at birth of 26 (25-27) weeks and postnatal age of 17 (14-24) days. There was no difference in %time with interface leak between prong and mask (0.9 (0-8)% vs 1.1 (0-18)%, p=0.82), %time with SpO₂ <80% (0.15 (0-1.2)% vs 0.06 (0-0.8)%, p=0.74) or heart rate <80/min (0.03 (0-0.2)% vs 0 (0-0.2)%, p=0.64). Three infants had interface leak for >10% of the time with prongs and 5 with the mask.

Conclusion: Both interfaces resulted in a similarly stable provision of positive airway pressure, and there was also no difference in the occurrence of intermittent hypoxia.