Effect of changing airway pressure on the ability of the human nose to warm and humidify air.
OBJECTIVE
Nasal continuous positive airway pressure (CPAP) treatment causes nasal symptoms that are believed to result from the drying effects of the air on the nasal mucosa, and these symptoms affect compliance with therapy. We hypothesized that the increased air pressure on the nasal mucosa caused by positive pressure from CPAP would decrease the ability of the nose to warm and humidify inspired air, explaining these symptoms.


METHODS
We performed a 4-way crossover trial using CPAP pressures of -5, 0, +5, and +10 cm H2O in 10 subjects. The ability to warm and humidify inspired air was determined by measurement of the temperature of a fixed volume of cold, dry air entering and exiting the nostril and calculation of the amount of water supplied to the airstream by the nose.


RESULTS
The water content of air was unaffected at the pressures studied.


CONCLUSIONS
The pressure of delivered CPAP does not affect the ability of the nose to warm and humidify inspired air.
Sahin-Yilmaz
Asli
A
Department of Surgery, Section of Otolaryngology-Head and Neck Surgery, University of Chicago, Chicago, Illinois 60637, USA.
Baroody
Fuad M
FM
DeTineo
Marcy
M
Cuttance
Georgina
G
Makinson
Doug
D
Pinto
Jayant M
JM
Naureckas
Edward T
ET
Naclerio
Robert M
RM
D000328:Adult; D000388:Air; D045422:Continuous Positive Airway Pressure; D018592:Cross-Over Studies; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008297:Male; D009666:Nose / Q000502:physiology*; D011446:Prospective Studies