Expiratory Flow Limitation During Spontaneous Breathing

Comparison of Patients With Restrictive and Obstructive Respiratory Disorders

¹ From the Chest Medicine Service, Rancho Los Amigos Medical Center, Downey, Calif, and the Division of Pulmonary and Critical Care, Department of Medicine, University of Southern California School of Medicine, Los Angeles
² Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada

Background and study objectives: Comparison of tidal and forced expiratory flow-volume (V-V) curves has inherent technical problems in the characterization of expiratory flow limitation. In addition, patients with neuromuscular disorders may be unable to perform forced expiratory maneuvers because of muscle weakness or poor coordination. A recently developed simple, noninvasive technique that avoids these problems was used to detect expiratory flow limitation at rest in 19 seated patients with restrictive respiratory (13 with musculoskeletal) disorders (RD) and 20 with chronic obstructive airway disease (COAD).

Setting: A large rehabilitation hospital for the care of patients with chronic musculoskeletal and respiratory disorders.

Interventions and measurements: The method consisted of applying negative pressure of about 5 cm H₂O at the airway opening during expiration and comparing the ensuing V-V curve to the preceding tidal V-V curve.

Results: While nine patients with COAD demonstrated flow limitation, only one patient with RD did so. Patients with expiratory flow limitation exhibited various contours of the control tidal expiratory V-V curve. Thus, inspection of the tidal V-V curve is not a reliable means of detecting expiratory flow limitation.

Conclusions: We conclude that expiratory flow limitation during resting breathing is common in patients with COAD but not in patients with RD.

Key Words: COAD • expiratory flow limitation • negative expiratory pressure method • restrictive disease • tidal flow-volume curves

Submitted on June 19, 1996
Accepted on April 9, 1997

This article has been cited by other articles:

				P. M. A. Calverley and N. G. Koulouris Flow limitation and dynamic hyperinflation: key concepts in modern respiratory physiology Eur. Respir. J., January 1, 2005; 25(1): 186 - 199. [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]

				A. Baydur, L. Wilkinson, R. Mehdian, B. Bains, and J. Milic-Emili Extrathoracic Expiratory Flow Limitation in Obesity and Obstructive and Restrictive Disorders: Effects of Increasing Negative Expiratory Pressure Chest, January 1, 2004; 125(1): 98 - 105. [Abstract] [Full Text] [PDF]

				P.-H. Wang, P.-H. Kuo, C.-L. Hsu, H.-D. Wu, Y.-S. Chang, S.-H. Kuo, and P.-C. Yang Diagnostic Value of Negative Expiratory Pressure for Airway Hyperreactivity Chest, November 1, 2003; 124(5): 1762 - 1767. [Abstract] [Full Text] [PDF]

				N.G. Koulouris, S. Retsou, E. Kosmas, K. Dimakou, K. Malagari, G. Mantzikopoulos, A. Koutsoukou, J. Milic-Emili, and J. Jordanoglou Tidal expiratory flow limitation, dyspnoea and exercise capacity in patients with bilateral bronchiectasis Eur. Respir. J., May 1, 2003; 21(5): 743 - 748. [Abstract] [Full Text] [PDF]

				B. D. Johnson, K. C. Beck, R. J. Zeballos, and I. M. Weisman Advances in Pulmonary Laboratory Testing Chest, November 1, 1999; 116(5): 1377 - 1387. [Abstract] [Full Text] [PDF]