Prevalence and correlates of a ‘knee’ pattern on the maximal expiratory flow-volume loop in young adults

Respirology ◽  
2014 ◽  
Vol 19 (7) ◽  
pp. 1052-1058 ◽  
Author(s):  
Hayden H. Shin ◽  
Malcolm R. Sears ◽  
Robert J. Hancox
Keyword(s):  
Young Adults ◽  
Flow Volume ◽  
Maximal Expiratory Flow ◽  
Flow Volume Loop ◽  
Expiratory Flow

Pattern and mechanism of airway response to hypocapnia in normal subjects

1979 ◽  
Vol 47 (1) ◽  
pp. 8-12 ◽  
Author(s):  
C. F. O'Cain ◽  
M. J. Hensley ◽  
E. R. McFadden ◽  
R. H. Ingram
Keyword(s):  
Vital Capacity ◽  
Normal Subjects ◽  
Oxygen Mixture ◽  
Flow Volume ◽  
Mixture Density ◽  
Lung Capacity ◽  
Airway Constriction ◽  
Maximal Expiratory Flow ◽  
Airway Response ◽  
Expiratory Flow

We examined the bronchoconstriction produced by airway hypocapnia in normal subjects. Maximal expiratory flow at 25% vital capacity on partial expiratory flow-volume (PEFV) curves fell during hypocapnia both on air and on an 80% helium- 20% oxygen mixture. Density dependence also fell, suggesting predominantly small airway constriction. The changes seen on PEFV curves were not found on maximal expiratory flow-volume curves, indicating the inhalation to total lung capacity substantially reversed the constriction. Pretreatment with a beta-sympathomimetic agent blocked the response, whereas atropine pretreatment did not, suggesting that hypocapnia affects airway smooth muscle directly, not via cholinergic efferents.

scholarly journals Shape Analysis of the Maximal Expiratory Flow Volume Curve Among the Patients with Various Kind of Pulmonary Diseases

1982 ◽  
Vol 29 (1) ◽  
pp. 30-36
Author(s):  
Song Hyun Nam ◽  
Hyun Ha Park ◽  
Re Hwe Kim ◽  
Sung Koo Han ◽  
Ye Won Kim ◽  
...  
Keyword(s):  
Shape Analysis ◽  
Pulmonary Diseases ◽  
Flow Volume ◽  
Maximal Expiratory Flow ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Expiratory Flow

scholarly journals Longitudinal Examination of the Shape of the Maximum Expiratory Flow‐Volume Curve in Young Adults Following SARS‐CoV‐2 Infection

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Jonathon Stickford ◽  
Marc Augenreich ◽  
Valesha Province ◽  
Nina Stute ◽  
Abigail Stickford ◽  
...  
Keyword(s):  
Young Adults ◽  
Flow Volume ◽  
Volume Curve ◽  
Maximum Expiratory Flow ◽  
Flow Volume Curve ◽  
Expiratory Flow ◽  
Longitudinal Examination

Volume Adjustment of Maximal Expiratory Flow Rates of Flow-Volume Loops

CHEST Journal ◽  
1992 ◽  
Vol 102 (5) ◽  
pp. 1636-1637
Author(s):  
Sema Umut ◽  
Bilun Gemicioğlu ◽  
Nurhayat Yildirim
Keyword(s):  
Flow Volume ◽  
Flow Rates ◽  
Maximal Expiratory Flow ◽  
Expiratory Flow ◽  
Expiratory Flow Rates

Relation of concavity in the expiratory flow-volume loop to dynamic hyperinflation during exercise in COPD

2016 ◽  
Vol 234 ◽  
pp. 79-84 ◽  
Author(s):  
Janos Varga ◽  
Richard Casaburi ◽  
Shuyi Ma ◽  
Ariel Hecht ◽  
David Hsia ◽  
...  
Keyword(s):  
Dynamic Hyperinflation ◽  
Flow Volume ◽  
Flow Volume Loop ◽  
Expiratory Flow

Spirometry and Maximal Expiratory Flow-Volume Curve Reference Standards for Polynesian, European, and Chinese Teenagers

CHEST Journal ◽  
1988 ◽  
Vol 94 (4) ◽  
pp. 792-798 ◽  
Author(s):  
Françoise Neukirch ◽  
René Chansin ◽  
Renata Liard ◽  
Monique Levallois ◽  
Philippe Leproux
Keyword(s):  
Reference Standards ◽  
Flow Volume ◽  
Maximal Expiratory Flow ◽  
Volume Curve ◽  
Flow Volume Curve ◽  
Expiratory Flow

Evaluation of Major Airway Lesions Using the Flow-Volume Loop

1975 ◽  
Vol 84 (5) ◽  
pp. 635-642 ◽  
Author(s):  
Robert E. Hyatt
Keyword(s):  
Vital Capacity ◽  
Inspiratory Flow ◽  
Flow Volume ◽  
Flow Volume Loop ◽  
Expiratory Flow

The flow-volume (FV) loop is another way of representing spirometric data from combinations of forced expiratory and forced inspiratory vital capacity breaths. The FV loop is of use in identifying, and often localizing, lesions of the larynx and the trachea (down to the carina). Three general patterns have been recognized. When the lesion behaves in a fixed fashion (as might occur with an artificial orifice), maximal expiratory and inspiratory flows are almost equally compromised. This results in a rectangular FV loop, irrespective of whether the lesion is located intrathoracically or extrathoracically. When the lesion behaves in a variable fashion, two distinct patterns are seen, depending on the location of the lesion (intrathoracic or extrathoracic). The variable lesion acts as a fixed lesion during one phase of forced respiration only. The extrathoracic variable lesion results in a predominant reduction in forced inspiratory flow, with little effect on expiratory flow, whereas the intrathoracic variable lesion produces a characteristic reduction in expiratory flow. These patterns reflect the transmural forces existing at the site of the lesion.

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