Journal of Applied Physiology, Vol 71, Issue 6 2317-2324, Copyright © 1991 by American Physiological Society

ARTICLES

Nasal and oral airway pressure-flow relationships

J. R. Wheatley, T. C. Amis and L. A. Engel
Thoracic Medicine Unit, Westmead Hospital, Sydney, New South Wales, Australia.

We examined the inspiratory and expiratory pressure-flow relationships of both the oral and nasal airways before and after exercise in normal upright subjects. With the use of a partitioned facemask, nasal resistance was measured using posterior rhinomanometry, and oral resistance was measured by recording transoral pressure during oral breathing. Both the nasal and oral pressure-flow relationships for inspiration and expiration were curvilinear and were well described by a power function of the form delta P = aVb (where P is pressure, V is flow, a and b are constants) (r2 = 0.96 +/- 0.01). The exponent b describes the curvilinearity of the pressure-flow curve and can be used to infer the flow regimen. At rest, the inspiratory nasal and oral curves suggested a similar degree of turbulence (b = 1.77 +/- 0.06 and 1.83 +/- 0.04, respectively). However, inspiratory flow regimens were inferred to be more turbulent than those during expiration both before and after exercise. After exercise, decreases in inspiratory nasal resistance at low flows were associated with a change in flow regimen from fully turbulent to orifice flow over the entire flow range. Thus the application of a power function to nasal and oral pressure-flow data permits representation of the whole relationship and allows insight into the nature of the flow regimens.

This article has been cited by other articles:

				K. Kairaitis, L. Howitt, J. R. Wheatley, and T. C. Amis Mass loading of the upper airway extraluminal tissue space in rabbits: effects on tissue pressure and pharyngeal airway lumen geometry J Appl Physiol, March 1, 2009; 106(3): 887 - 892. [Abstract] [Full Text] [PDF]

				M. Hallani, J. R. Wheatley, and T. C. Amis Initiating oral breathing in response to nasal loading: asthmatics versus healthy subjects Eur. Respir. J., April 1, 2008; 31(4): 800 - 806. [Abstract] [Full Text] [PDF]

				M. Brouns, S. T. Jayaraju, C. Lacor, J. De Mey, M. Noppen, W. Vincken, and S. Verbanck Tracheal stenosis: a flow dynamics study J Appl Physiol, March 1, 2007; 102(3): 1178 - 1184. [Abstract] [Full Text] [PDF]

				M.R. Madronio, E. Di Somma, R. Stavrinou, J.P. Kirkness, E. Goldfinch, J.R. Wheatley, and T.C. Amis Older individuals have increased oro-nasal breathing during sleep Eur. Respir. J., July 1, 2004; 24(1): 71 - 77. [Abstract] [Full Text] [PDF]

				F. Series and G. Ethier Site of phrenic nerve stimulation-induced upper airway collapse: influence of expiratory time J Appl Physiol, February 1, 2002; 92(2): 665 - 671. [Abstract] [Full Text] [PDF]

				J. M. Gehring, S. R. Garlick, J. R. Wheatley, and T. C. Amis Nasal resistance and flow resistive work of nasal breathing during exercise: effects of a nasal dilator strip J Appl Physiol, September 1, 2000; 89(3): 1114 - 1122. [Abstract] [Full Text] [PDF]

				T C Amis, N O'Neill, and J R Wheatley Oral airway resistance during wakefulness in patients with obstructive sleep apnoea Thorax, May 1, 1999; 54(5): 423 - 426. [Abstract] [Full Text]

				T C Amis, N O'Neill, and J R Wheatley Oral airway flow dynamics in healthy humans J. Physiol., February 15, 1999; 515(1): 293 - 298. [Abstract] [Full Text] [PDF]

				Y. CORMIER, M. LAVIOLETTE, G. BEDARD, J. DOSMAN, and E. ISRAEL-ASSAYAG Effect of Route of Breathing on Response to Exposure in a Swine Confinement Building Am. J. Respir. Crit. Care Med., May 1, 1997; 157(5): 1512 - 1521. [Abstract] [Full Text]