Comparison of the pharyngeal pressure provided by two heated, humidified high‐flow nasal cannulae devices in premature infants

Aims This study aims to determine if there is a difference in the pharyngeal pressure, measured as a surrogate for continuous positive distending airway pressure, delivered to premature infants between two commonly used heated, humidified high‐flow nasal cannulae ( HHHFNC ) devices: F isher & P aykel H ealthcare HHHFNC and V apotherm 2000i. Methods Pharyngeal pressure measurements were taken from stable premature infants receiving HHHFNC for respiratory support. Flow rates of 2–8 L/min were studied. Results Nine infants had pharyngeal pressure measurements recorded with both HHHFNC devices at flow rates of 2–8 L/min. There was no difference in pharyngeal pressures recorded between devices at flow rates of 2–6 L/min; measured pressure was linearly associated with flow ( R 2 = 0.9). At flow rates of 7 L/min, V apotherm delivered a mean (standard deviation) pharyngeal pressure of 4.7 (2.2) cmH 2 O compared with 4.23 (2.2) cmH 2 O by the F isher & P aykel device ( P = 0.04). At a flow of 8 L/min, the mean pharyngeal pressure via V apotherm was 4.9 (2.2) cmH 2 O compared with 4.1 (2.3) cmH 2 O with the F isher & P aykel device ( P = 0.05). Conclusions Both HHHFNC delivered similar pharyngeal pressures at flow rates of 2–6 L/min. The pressure limiter valve of the F isher & P aykel device attenuated the pharyngeal pressures at flows of 7 and 8 L/min. V apotherm trended towards higher delivered pharyngeal pressure at flow rates 7 and 8 L/min, but the clinical significance of the difference remains unclear.