Work of breathing using high-flow nasal cannula in preterm infants.

OBJECTIVE: To compare the work of breathing (WOB) in premature neonates supported with high-flow nasal cannula (HFNC) and nasal continuous positive airway pressure (NCPAP). STUDY DESIGN: Eighteen preterm neonates <2.0 kg on HFNC or NCPAP support were studied in a random order. A ventilator was used to deliver 6 cm H2O of NCPAP with nasal prongs. High-flow nasal cannula delivered with Vapotherm (VAPO) at 3, 4 and 5 l/min was used. Tidal ventilation was obtained using respiratory inductance plethysmography calibrated with face-mask pneumotachography. An esophageal balloon estimated pleural pressure from which changes in end distending pressure were calculated. Inspiratory, elastic and resistive WOB and respiratory parameters were calculated. RESULTS: No differences were found in the WOB for all settings. Changes in end distending pressure did not vary significantly over all device settings except VAPO at 5 l/min. CONCLUSION: In these preterm infants with mild respiratory illness, HFNC provided support comparable to NCPAP.