Tidal volume transmission during non-synchronized nasal intermittent positive pressure ventilation via RAM ® cannula.

BACKGROUND: Nasal intermittent positive pressure ventilation (NIPPV) is a widely used mode of support in neonates, during which ventilator inflations may or may not coincide with spontaneous breathing.

OBJECTIVE: We tested the hypothesis that inflations delivered with NIPPV via RAM® cannula and not accompanied by patient effort produce minimal tidal volume as measured by respiratory inductance plethysmography.

DESIGN/METHODS: Fourteen subjects were monitored while receiving NIPPV. We compared tidal volumes during ventilator-supported breaths, unsupported breaths, and ventilator inflations not accompanied by patient effort (defined using electrical activity of the diaphragm).

RESULTS: Mean tidal volumes in arbitrary units were 0.30 ± 0.22 in NIPPV inflations associated with patient effort and 0.27 ± 0.15 in spontaneous breaths without ventilator assistance (p = 0.82). Tidal volumes during ventilator-only inflations were 0.06 ± 0.04 (p < 0.005 vs. both ventilator-assisted and unassisted efforts).

CONCLUSIONS: NIPPV via RAM cannula produces minimal, clinically insignificant tidal volumes during non-spontaneous inflations.