Effect of high‐frequency oscillation on pressure delivered by high flow nasal cannula in a premature infant lung model

摘要

Abstract Objective This study describes the effect of high‐frequency oscillation on airway pressure generated by high flow nasal cannula (HFNC) in a premature infant lung model. Design/Methods A premature in 0.5 or 1.0?mL/cmH 2 O, respiratory rate (RR) of 40 or 60 breaths per min, and tidal volume of 6?mL. Oscillation was achieved by passing the HFNC supply flow through a 3‐way solenoid valve operating at 4, 6, 8, or 10?Hz. Airway pressure at the simulated trachea was recorded following equilibration of end‐tidal CO 2 both with and without oscillation. Results Superimposing high‐frequency oscillations onto HFNC resulted in an average decrease in mean airway pressure of 17.9% ( P ?=?.011). The difference between the maximum and minimum airway pressures, ? P min‐max, significantly increased as oscillation frequency decreased ( P ??.001). Airway pressure during oscillation was 12.8% greater with the 1.0 vs the 0.5?mL/cmH 2 O compliance at flows??4?L/min ( P ?=?.031). CO 2 clearance was 13.1% greater with the 1.0 vs 0.5?mL/cmH 2 O compliance at oscillation frequencies less than 8?Hz ( P ?=?.015). Conclusion In this in‐vitro study we demonstrate that delivered mean airway pressure decreases when applying high‐frequency oscillation to HFNC, while still improving CO 2 clearance. The combination of improved CO 2 clearance and reduced pressure delivery of this novel noninvasive modality may prove to be a useful improvement in the respiratory care of infants in respiratory distress.