Am. J. Respir. Crit. Care Med., Volume 161, Number 1, January 2000, 50-56

Airway-Parenchyma Uncoupling in Nocturnal Asthma

CHARLES G. IRVIN, JUNO PAK, and RICHARD J. MARTIN

Pulmonary Disease and Critical Care Medicine, Molecular Physiology and Biophysics, University of Vermont, Colchester, Vermont; and Pulmonary Division, Department of Medicine, National Jewish Medical and Research Center, and University of Colorado Health Sciences Center, Denver, Colorado

Airway flow resistance is well known to be dependent upon lung volume. The rise in lung volume that occurs in asthma is therefore thought to be an important mechanism that defends airway patency. The purpose of the current study was to investigate the interdependence or mechanical coupling between airways and lung parenchyma during the inflammatory processes that occur in the patient with nocturnal asthma. Five patients with documented nocturnal asthma were studied in both a vertical and a horizontal body plethysmograph. Lung volume was altered with continuous negative pressure as applied to the chest wall with a poncho cuirass in different postures and during sleep. We found during the awake phase that an increase in lung volume decreased lower pulmonary resistance (Rlp); however, within 30 min of sleep onset, functional residual capacity (FRC) fell and Rlp rose more than would be expected for the fall in FRC. Restoring FRC to presleep values either at an early (half-hour) or a late (3-h) time point did not cause Rlp to significantly fall. A second phase of the study showed that the loss of Rlp dependence on lung volume was not due to the assumption of the supine posture. Indirect measurements of lung compliance were consistent with a stiffening of the lung. We conclude that with sleep there is an immediate uncoupling of the parenchyma to the airway, resulting in a loss of interdependence that persists throughout sleep and may contribute to the morbidity and mortality associated with nocturnal asthma. Irvin CG, Pak J, Martin RJ. Airway-parenchyma uncoupling in nocturnal asthma.

This article has been cited by other articles:

				C. G. Irvin and J. H. T. Bates Physiologic Dysfunction of the Asthmatic Lung: What's Going On Down There, Anyway? Proceedings of the ATS, May 1, 2009; 6(3): 306 - 311. [Abstract] [Full Text] [PDF]

				R. L. Sorkness, E. R. Bleecker, W. W. Busse, W. J. Calhoun, M. Castro, K. F. Chung, D. Curran-Everett, S. C. Erzurum, B. M. Gaston, E. Israel, et al. Lung function in adults with stable but severe asthma: air trapping and incomplete reversal of obstruction with bronchodilation J Appl Physiol, February 1, 2008; 104(2): 394 - 403. [Abstract] [Full Text] [PDF]

				S. S. An, T. R. Bai, J. H. T. Bates, J. L. Black, R. H. Brown, V. Brusasco, P. Chitano, L. Deng, M. Dowell, D. H. Eidelman, et al. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma Eur. Respir. J., May 1, 2007; 29(5): 834 - 860. [Abstract] [Full Text] [PDF]

				S. S. Wagers, H. C. Haverkamp, J. H. T. Bates, R. J. Norton, J. A. Thompson-Figueroa, M. J. Sullivan, and C. G. Irvin Intrinsic and antigen-induced airway hyperresponsiveness are the result of diverse physiological mechanisms J Appl Physiol, January 1, 2007; 102(1): 221 - 230. [Abstract] [Full Text] [PDF]

				C. Y. Seow Are you pulling my airway? Eur. Respir. J., November 1, 2005; 26(5): 759 - 761. [Full Text] [PDF]

				T. Mauad, L. F. F. Silva, M. A. Santos, L. Grinberg, F. D. C. Bernardi, M. A. Martins, P. H. N. Saldiva, and M. Dolhnikoff Abnormal Alveolar Attachments with Decreased Elastic Fiber Content in Distal Lung in Fatal Asthma Am. J. Respir. Crit. Care Med., October 15, 2004; 170(8): 857 - 862. [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]

				C.G. Irvin Lung volume: a principle determinant of airway smooth muscle function Eur. Respir. J., July 1, 2003; 22(1): 3 - 5. [Full Text] [PDF]

				B. E. McParland, P. T. Macklem, and P. D. Pare Airway wall remodeling: friend or foe? J Appl Physiol, July 1, 2003; 95(1): 426 - 434. [Abstract] [Full Text] [PDF]

				W. J. Calhoun Nocturnal Asthma Chest, March 1, 2003; 123 (2009): 399S - 405S. [Abstract] [Full Text] [PDF]

				E. Crimi, R. Pellegrino, M. Milanese, and V. Brusasco Deep breaths, methacholine, and airway narrowing in healthy and mild asthmatic subjects J Appl Physiol, October 1, 2002; 93(4): 1384 - 1390. [Abstract] [Full Text] [PDF]

				E. L. Bijaoui, V. Champagne, P. F. Baconnier, R. J. Kimoff, and J. H. T. Bates Mechanical Properties of the Lung and Upper Airways in Patients with Sleep-disordered Breathing Am. J. Respir. Crit. Care Med., April 15, 2002; 165(8): 1055 - 1061. [Abstract] [Full Text] [PDF]

				M. J. TOBIN Asthma, Airway Biology, and Allergic Rhinitis in AJRCCM 2000 Am. J. Respir. Crit. Care Med., November 1, 2001; 164(9): 1559 - 1580. [Full Text] [PDF]

				D. A. KAMINSKY, J. H. T. BATES, and C. G. IRVIN Effects of Cool, Dry Air Stimulation on Peripheral Lung Mechanics in Asthma Am. J. Respir. Crit. Care Med., July 1, 2000; 162(1): 179 - 186. [Abstract] [Full Text]