Increased work of breathing associated with nasal prongs

To see if continuous distending pressure (CPD) given by nasal prongs increases work of breathing, we measured the mechanics of breathing, minute ventilation, and blood gases in nine infants with both nasal prong and face mask CDP. Minute ventilation was 16% larger (P less than .02), work of breathing was 94% higher (P less than .01), and the mean PaO2 was 8 mm Hg lower (P less than .03) with the nasal prongs. There was no difference in pH or PaCO2. We speculate that CDP given by nasal prongs may increase the risk of respiratory failure in the premature infant already compromised with hyaline membrane disease.