scholarly journals Shape of the Expiratory Flow-volume Curve of Chronic Obstructive Pulmonary Disease and Interstitial Pneumonia Patients at Rest and during Exercise

2012 ◽  
Vol 27 (4) ◽  
pp. 379-383
Author(s):  
Masafumi NOZOE ◽  
Kyoshi MASE ◽  
Shigefumi MURAKAMI ◽  
Makoto OKADA ◽  
Tomoyuki OGINO ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Interstitial Pneumonia ◽  
Chronic Obstructive ◽  
Flow Volume ◽  
Obstructive Pulmonary Disease ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Expiratory Flow

scholarly journals The Concavity of the Maximal Expiratory Flow–Volume Curve Reflects the Extent of Emphysema in Obstructive Lung Diseases

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fumi Mochizuki ◽  
Hiroaki Iijima ◽  
Azusa Watanabe ◽  
Naoya Tanabe ◽  
Susumu Sato ◽  
...  
Keyword(s):  
Vital Capacity ◽  
Chronic Obstructive ◽  
Flow Volume ◽  
Obstructive Pulmonary Disease ◽  
Wall Area ◽  
Maximal Expiratory Flow ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Expiratory Flow ◽  
Volume Difference

Abstract A concave-shaped maximal expiratory flow-volume (MEFV) curve is a spirometric feature in chronic obstructive pulmonary disease (COPD). The MEFV curve is characterized by an increase in the Obstructive Index, which is defined as a ratio of forced vital capacity to the volume-difference between two points of half of the peak expiratory flow on the MEFV curve. We hypothesized that the Obstructive Index would reflect the severity of emphysema in patients with COPD and asthma-COPD overlap (ACO). Thus, the aim of this retrospective study was to evaluate whether the Obstructive Index on spirometry is associated with the extent of emphysema on computed tomography (CT) in patients with COPD, ACO, and asthma (N = 65, 15, and 53, respectively). The percentage of low-attenuation volume (LAV%) and wall area (WA%) were measured on CT. The Obstructive Index was higher in patients with COPD and ACO than in those with asthma. Spearman correlation showed that a greater Obstructive Index was associated with a higher LAV%, but not WA%. Multivariate analysis showed that Obstructive Index was associated with LAV% (standardized β = 0.43, P < 0.0001) independent of other spirometric indices. The Obstructive Index is a useful spirometric index that reflects the extent of emphysema.

scholarly journals Tidal expiratory flow limitation induces expiratory looping of the alveolar pressure-flow relation in COPD patients

2020 ◽  
Vol 129 (1) ◽  
pp. 75-83
Author(s):  
Matteo Pecchiari ◽  
Dejan Radovanovic ◽  
Camilla Zilianti ◽  
Laura Saderi ◽  
Giovanni Sotgiu ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Chronic Obstructive ◽  
Flow Limitation ◽  
Alveolar Pressure ◽  
Expiratory Flow Limitation ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Expiratory Flow ◽  
Spontaneously Breathing

In stable chronic obstructive pulmonary disease (COPD) patients spontaneously breathing at rest, tidal expiratory flow limitation is the major determinant of the occurrence of expiratory looping in the plethysmographic flow-alveolar pressure diagram. In these patients the magnitude and the characteristics of the loop can be used as predictors of the presence of tidal expiratory flow limitation.

Detection of expiratory flow limitation during exercise in COPD patients

1997 ◽  
Vol 82 (3) ◽  
pp. 723-731 ◽  
Author(s):  
Nickolaos G. Koulouris ◽  
Ioanna Dimopoulou ◽  
Päivi Valta ◽  
Richard Finkelstein ◽  
Manuel G. Cosio ◽  
...  
Keyword(s):  
Normal Subjects ◽  
Chronic Obstructive ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Obstructive Pulmonary Disease ◽  
Normal Limits ◽  
Volume Curve ◽  
Copd Patients ◽  
Flow Volume Curve ◽  
Expiratory Flow

Koulouris, Nickolaos G., Ioanna Dimopoulou, Päivi Valta, Richard Finkelstein, Manuel G. Cosio, and J. Milic-Emili.Detection of expiratory flow limitation during exercise in COPD patients. J. Appl. Physiol. 82(3): 723–731, 1997.—The negative expiratory pressure (NEP) method was used to detect expiratory flow limitation at rest and at different exercise levels in 4 normal subjects and 14 patients with chronic obstructive pulmonary disease (COPD). This method does not require performance of forced expirations, nor does it require use of body plethysmography. It consists in applying negative pressure (−5 cmH2O) at the mouth during early expiration and comparing the flow-volume curve of the ensuing expiration with that of the preceding control breath. Subjects in whom application of NEP does not elicit an increase in flow during part or all of the tidal expiration are considered flow limited. The four normal subjects were not flow limited up to 90% of maximal exercise power output (W˙max). Five COPD patients were flow limited at rest, 9 were flow limited at one-third W˙max, and 12 were flow limited at two-thirdsW˙max. Whereas in all patients who were flow limited at rest the maximal O2 uptake was below the normal limits, this was not the case in most of the other patients. In conclusion, NEP provides a rapid and reliable method to detect expiratory flow limitation at rest and during exercise.

Forced Expiratory Flow Is Reduced by 100% Oxygen in Patients With Chronic Obstructive Pulmonary Disease

1995 ◽  
Vol 88 (4) ◽  
pp. 443-449 ◽  
Author(s):  
LTC JAMES E. JOHNSON ◽  
MAJ MARK D. PEACOCK ◽  
CPT JACKIE A. HAYES ◽  
MAJ MICHAEL J. MORRIS ◽  
MAJ GREGG T. ANDERS ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Forced Expiratory Flow ◽  
Expiratory Flow
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