title: Comparison of the pharyngeal pressure provided by two heated, humidified high-flow nasal cannulae devices in premature infants.
abstract: OBJECTIVE
  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: Fisher & Paykel Healthcare HHHFNC and Vapotherm 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, Vapotherm delivered a mean (standard deviation) pharyngeal pressure of 4.7 (2.2) cmH2 O compared with 4.23 (2.2) cmH2 O by the Fisher & Paykel device (P = 0.04). At a flow of 8 L/min, the mean pharyngeal pressure via Vapotherm was 4.9 (2.2) cmH2 O compared with 4.1 (2.3) cmH2 O with the Fisher & Paykel 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 Fisher & Paykel device attenuated the pharyngeal pressures at flows of 7 and 8 L/min. Vapotherm trended towards higher delivered pharyngeal pressure at flow rates 7 and 8 L/min, but the clinical significance of the difference remains unclear.
authors.affiliation: Department of Paediatrics, Mercy Hospital for Women, Melbourne, VIC 3084, Australia.
authors.forename: Clare L
authors.initials: CL
authors.lastname: Collins
authors.forename: James R
authors.initials: JR
authors.lastname: Holberton
authors.forename: Kai
authors.initials: K
authors.lastname: König
mesh_terms: D057785:Catheters; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D005260:Female; D006361:Heating; D006801:Humans; D006813:Humidity; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D010614:Pharynx; D011312:Pressure
keywords: continuous positive airway pressure; heated; humidified high-flow nasal cannula; infant; non-invasive ventilation; premature