Send to

Choose Destination
Respir Care. 2013 Oct;58(10):1621-4. doi: 10.4187/respcare.02358. Epub 2013 Mar 19.

Pressures delivered by nasal high flow oxygen during all phases of the respiratory cycle.

Author information

Cardiothoracic and Vascular Intensive Care Unit, Auckland City Hospital, Auckland, New Zealand.



Nasal high flow (NHF) oxygen therapy and CPAP are modes of noninvasive respiratory support used to improve respiratory function in multiple patient groups. Both therapies provide positive pressure, although this varies during the respiratory cycle. The purpose of this study was to measure and compare the airway pressure generated during different phases of the respiratory cycle in patients receiving NHF at various gas flows.


Patients scheduled for elective cardiac surgery were invited to participate. Nasopharyngeal pressure measurements were performed using NHF with gas flows of 30, 40, and 50 L/min. All measurements were performed in random order, with the subject breathing with mouth closed.


During NHF the mean ± SD nasopharyngeal airway pressures were 1.5 ± 0.6, 2.2 ± 0.8, and 3.1 ± 1.2 at 30, 40, and 50 L/min using NHF. Analyses also determined the mean peak expiratory and mean expiratory plateau pressures.


The expiratory pressure during NHF was higher than the mean pressure previously reported for NHF. This may account in part for the disproportional clinical effects seen with NHF. (Australian Clinical Trials Registry ACTRN12609000305224).


airway pressure; nasal high flow oxygen; noninvasive ventilation; oxygen

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center