Comparison of Effort of Breathing for Infants on Nasal Modes of Respiratory Support.

OBJECTIVE: To directly compare effort of breathing between high flow nasal cannula (HFNC), nasal intermittent mechanical ventilation (NIMV), and nasal continuous positive airway pressure (NCPAP).

STUDY DESIGN: This was a single center prospective cross-over study for patients <6 months in the cardiothoracic or pediatric intensive care unit receiving nasal noninvasive respiratory support after extubation. We measured effort of breathing using esophageal manometry with pressure-rate product (PRP) on all 3 modes. NIMV synchrony was determined by comparing patient efforts (esophageal manometry) with mechanically delivered breaths (spirometry in ventilator circuit). On NIMV, PRP and synchrony was also measured after adding a nasal clip on 26 patients.

RESULTS: Forty-two children were included. Median (IQR) age was 2 (0.5, 4) months. There was no difference in median PRP between HFNC 6 liters per minute, 355 (270,550), NIMV 12/5 cm H2 O, 341 (235, 472), and NCPAP 5 cm H2 O, 340 (245,506) (P?=?.33). Results were similar regardless of HFNC flow rate or NIMV inspiratory pressure. Median PRP on CPAP of 5 cm H2 O prior to extubation 255 (176, 375) was significantly lower than all postextubation values (P?<?.002). On NIMV, less than 50% of patient efforts resulted in a ventilator breath, which was not improved with a nasal clip (P?>?.07)). However, as NIMV synchrony improved (>60%), PRP on NIMV was lower than on HFNC.

CONCLUSIONS: For infants, effort of breathing is similar on HFNC, NIMV, and NCPAP after extubation, regardless of flow rate or inspiratory pressure. We speculate that bi-level NIMV may be superior if high levels of synchrony can be achieved.