| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Fisiopatologia Respiratoria and 2 Medicina Nucleare, Azienda Ospedaliera S. Croce e Carle, 12110 Cuneo, Italy; 3 Pulmonary and Critical Care Section, Baylor College of Medicine, Houston, Texas 77030; and 4 Cattedra di Fisiopatologia Respiratoria, Dipartimento di Scienze Motorie e Riabilitative, Università di Genova, 16132 Genova, Italy
Regional expiratory flow limitation (EFL) may occur during tidal breathing without being detected by measurements of flow at the mouth. We tested this hypothesis by using Technegas to reveal sites of EFL. A first study (study 1) was undertaken to determine whether deposition of Technegas during tidal breathing reveals the occurrence of regional EFL in induced bronchoconstriction. Time-activity curves of Technegas inhaled during 12 tidal breaths were measured in four asthmatic subjects at control conditions and after exposure to inhaled methacholine at a dose sufficient to abolish expiratory flow reserve near functional residual capacity. A second study (study 2) was conducted in seven asthmatic subjects at control and after three increasing doses of methacholine to compare the pattern of Technegas deposition in the lung with the occurrence of EFL. The latter was assessed at the mouth by comparing tidal with forced expiratory flow or with the flow generated on application of a negative pressure. Study 1 documented enhanced and spotty deposition of Technegas in the central lung regions with increasing radioactivity during tidal expiration. This is consistent with increased impaction of Technegas on the airway wall downstream from the flow-limiting segment. Study 2 showed that both methods based on analysis of flow at the mouth failed to detect EFL at the time spotty deposition of Technegas occurred. We conclude that regional EFL occurs asynchronously across the lung and that methods based on mouth flow measurements are insensitive to it.
bronchoconstriction; methacholine; lung hyperinflation; negative expiratory pressure; flow-volume curve
This article has been cited by other articles:
|
|
 |
|
  P-R. Burgel, J. de Blic, P. Chanez, C. Delacourt, P. Devillier, A. Didier, J-C. Dubus, I. Frachon, G. Garcia, M. Humbert, et al. Update on the roles of distal airways in asthma Eur. Respir. Rev., June 1, 2009; 18(112): 80 - 95. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Campana, J. Kenyon, S. Zhalehdoust-Sani, Y.-S. Tzeng, Y. Sun, M. Albert, and K. R. Lutchen Probing airway conditions governing ventilation defects in asthma via hyperpolarized MRI image functional modeling J Appl Physiol, April 1, 2009; 106(4): 1293 - 1300. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. E. Hyatt, C. T. Cowl, J. A. Bjoraker, and P. D. Scanlon Conditions Associated With an Abnormal Nonspecific Pattern of Pulmonary Function Tests Chest, February 1, 2009; 135(2): 419 - 424. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Agostoni, M. Contini, G. Cattadori, A. Apostolo, S. Sciomer, M. Bussotti, P. Palermo, and C. Fiorentini Lung function with carvedilol and bisoprolol in chronic heart failure: Is {beta} selectivity relevant? Eur J Heart Fail, August 1, 2007; 9(8): 827 - 833. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Venegas Linking ventilation heterogeneity and airway hyperresponsiveness in asthma Thorax, August 1, 2007; 62(8): 653 - 654. [Full Text] [PDF]
|
|
|
|
|
|
M. Meinero, G. Coletta, L. Dutto, M. Milanese, G. Nova, A. Sciolla, R. Pellegrino, and V. Brusasco Mechanical response to methacholine and deep inspiration in supine men J Appl Physiol, January 1, 2007; 102(1): 269 - 275. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Petersson, A. Sanchez-Crespo, S. A. Larsson, and M. Mure Physiological imaging of the lung: single-photon-emission computed tomography (SPECT) J Appl Physiol, January 1, 2007; 102(1): 468 - 476. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Torchio, C. Gulotta, C. Ciacco, A. Perboni, M. Guglielmo, F. Crosa, M. Zerbini, V. Brusasco, R. E. Hyatt, and R. Pellegrino Effects of chest wall strapping on mechanical response to methacholine in humans J Appl Physiol, August 1, 2006; 101(2): 430 - 438. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Pellegrino, V. Brusasco, R. O. Crapo, and G. Viegi From the authors Eur. Respir. J., May 1, 2006; 27(5): 1070 - 1070. [Full Text] [PDF]
|
|
|
|
|
|
F. G. Salerno, R. Pellegrino, G. Trocchio, A. Spanevello, V. Brusasco, and E. Crimi Attenuation of induced bronchoconstriction in healthy subjects: effects of breathing depth J Appl Physiol, March 1, 2005; 98(3): 817 - 821. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P.G. Cox, J. Miller, W. Mitzner, and A.R. Leff Radiofrequency ablation of airway smooth muscle for sustained treatment of asthma: preliminary investigations Eur. Respir. J., October 1, 2004; 24(4): 659 - 663. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E.N. Kosmas, J. Milic-Emili, A. Polychronaki, I. Dimitroulis, S. Retsou, M. Gaga, A. Koutsoukou, Ch. Roussos, and N.G. Koulouris Exercise-induced flow limitation, dynamic hyperinflation and exercise capacity in patients with bronchial asthma Eur. Respir. J., September 1, 2004; 24(3): 378 - 384. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Petersson, A. Sanchez-Crespo, M. Rohdin, S. Montmerle, S. Nyren, H. Jacobsson, S. A. Larsson, S. G. E. Lindahl, D. Linnarsson, R. W. Glenny, et al. Physiological evaluation of a new quantitative SPECT method measuring regional ventilation and perfusion J Appl Physiol, March 1, 2004; 96(3): 1127 - 1136. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Filippelli, R. Duranti, F. Gigliotti, R. Bianchi, M. Grazzini, L. Stendardi, and G. Scano Overall Contribution of Chest Wall Hyperinflation to Breathlessness in Asthma Chest, December 1, 2003; 124(6): 2164 - 2170. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Brusasco and R. Pellegrino Invited Review: Complexity of factors modulating airway narrowing in vivo: relevance to assessment of airway hyperresponsiveness J Appl Physiol, September 1, 2003; 95(3): 1305 - 1313. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. Brown, K. L. Zeman, and W. D. Bennett Ultrafine Particle Deposition and Clearance in the Healthy and Obstructed Lung Am. J. Respir. Crit. Care Med., November 1, 2002; 166(9): 1240 - 1247. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
