Imposed Resistance and Pressure Delivery Evaluation With a Novel Neonatal Noninvasive Interface

Abstract

Background: Nearly 50% of infants supported with bubble CPAP (B-CPAP) fail and require (re)intubation. Endotracheal tubes are known to impose high resistance, which may add to causal respiratory failure but only modest consideration is given to the resistance of neonatal nasal airway interfaces. We hypothesized that resistance and pressure are similar between e a novel prong interface prototype and F&P, RAM, and Hudson Prongs. Methods: We measured resistance between ET tubes and interfaces as pressure drop within an ANSI test lung at different flows. We then attached nasal airway interfaces (no ET tube) to a 3D printed 28 week preemie nasal airway model/ASL 5000 lung model. All interfaces were used occlusively and pressure was measured during spontaneous breathing. Mean resistances and lung model pressures were compared using ANOVA. Results: Resistance values were all within acceptable ISO standards among all Hudson, F&P, Prototype Prongs and ET tube (3.0 and 3.5 mm), and RAM (blue and orange). Prototype, Hudson, and F&P prongs’ resistance was lower than corresponding ET tubes and RAM cannulae sizes (P < .05; see Figure). Noninvasive interfaces provided greater lung model pressure (within 0.5 cm H₂O) than RAM cannula (P < .05) which was always at least 1 cm H₂O less than preset B-CPAP levels. Conclusions: Our studies indicate that novel prototype provides similar support and at similar resistance values as Hudson and F&P bi-nasal short prongs. A low resistance occlusive prong interface that provides adequate support and does not rely upon a complicated fixation is needed to support the large fraction of newborns that otherwise fail noninvasive support.

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