Effect of volume history on successive partial expiratory flow-volume maneuvers

Wellman, James J.; Brown, Robert; Ingram, R. H.; Mead, J.; McFadden, E. R.

doi:10.1152/jappl.1976.41.2.153

Cited by 33 publications

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“…In this connection, it should be noted that similar considerations pertain to comparison of tidal V-V curves with those obtained during partial forced expirations. Indeed, WELLMAN et al [35] have shown that in normal subjects the maximal flows obtained during a forced expiratory manoeuvre started from FRC depend on the previous volume history, similar to the FVC manoeuvres. By contrast, with the NEP method, the previous volume history is by definition fixed (figs 2 and 3).…”

Section: Discussionmentioning

confidence: 80%

A simple method to detect expiratory flow limitation during spontaneous breathing

Koulouris¹,

Valta²,

Lavoie³

et al. 1995

Eur Respir J

220

225

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A A s si im mp pl le e m me et th ho od d t to o d de et te ec ct t e ex xp pi ir ra at to or ry y f fl lo ow w l li im mi it ta at ti io on n d du ur ri in ng g s sp po on nt ta an ne eo ou us s b br re ea at th hi in ng g N.G. Koulouris*, P. Valta*, A. Lavoie*, C. Corbeil**, M. Chassé**, J. Braidy**, J. Milic-Emili*A simple method to detect expiratory flow limitation during spontaneous breathing. N.G. Koulouris, P. Valta, A. Lavoie, C. Corbeil, M. Chassé, J. Braidy, J. Milic-Emili. ERS Journals Ltd 1995. ABSTRACT: Patients with severe chronic obstructive pulmonary disease (COPD) often exhale along the same flow-volume curve during quiet breathing as during a forced expiratory vital capacity manoeuvre, and this has been taken as indicating flow limitation at rest. To obtain such curves, a body plethysmograph and the patient's co-operation are required. We propose a simple technique which does not entail these requirements. It consists in applying negative pressure at the mouth during a tidal expiration (NEP). Patients in whom NEP elicits an increase in flow throughout the expiration are not flow-limited. In contrast, patients in whom application of NEP does not elicit an increase in flow during most or part of the tidal expiration are considered as flowlimited. Using this technique, 26 stable COPD patients were studied sitting and supine.Eleven patients were flow-limited both seated and supine, eight were flow-limited only when supine, and seven were not flow-limited either seated or supine. Only 5 of 19 patients who were flow-limited seated and/or supine had severe ventilatory impairment (forced expiratory volume in one second (FEV 1 ) <40% predicted).We conclude that the NEP technique provides a simple, rapid, and reliable method for detection of expiratory flow limitation in spontaneously breathing subjects, which does not require the patient's co-operation, and can be applied in different body positions both at rest and during muscular exercise. Our results also indicate a high prevalence of flow limitation in COPD patients at rest, particularly when supine. Eur Respir J., 1995, 8, 306-313 It has long been suggested that patients with severe chronic obstructive pulmonary disease (COPD) may exhibit expiratory flow limitation at rest, as reflected by the fact that they breathe tidally along or above their maximum expiratory flow-volume curves [1][2][3]. The effects of expiratory flow limitation may be partly compensated by breathing at lung volumes higher than the relaxation volume of the respiratory system [3]. The latter condition, which is termed dynamic pulmonary hyperinflation, is associated with intrinsic positive endexpiratory pressure (PEEPi) [4]. The combined effects of increased flow resistance, dynamic hyperinflation and PEEPi place a severe burden on the inspiratory muscles of COPD patients [5][6][7], and may also contribute to dyspnoea [8].Though dynamic hyperinflation is the hallmark of expiratory flow limitation, the prevalence and clinical significance of this phenomenon have not been adequa...

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Section: Discussionmentioning

confidence: 80%

A simple method to detect expiratory flow limitation during spontaneous breathing

Koulouris¹,

Valta²,

Lavoie³

et al. 1995

Eur Respir J

220

225

View full text Add to dashboard Cite

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“…Wellman et al showed that the SF peaks obtained in partial maximal expiratory-flow curves decreased in successive maneuvers, thus implicating the involvement of the viscoelastic properties of the airway wall in the genesis of the SF peaks [13]. …”

Section: Discussionmentioning

confidence: 99%

Supramaximal Flows: Comparison between Asthmatics and Patients with Chronic Obstructive Pulmonary Disease

González

Fernández²,

Guardia³

et al. 2010

Respiration

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Background: The major motive that prompted this study was to investigate whether or not the differences in supramaximal flow (SF) behavior between patients suffering from asthma and patients suffering from chronic obstructive pulmonary disease (COPD) might aid in clarifying the differences in the physiopathology of the two diseases. Objectives: The aim of the present study was therefore to compare SFs in asthma and COPD patients with similar degrees of air-flow limitation. Methods: Twelve asthmatic patients were individually matched with 12 COPD patients by forced expiratory volume during the first second (FEV₁) as a percent (±5%) of the reference value (ΔFEV₁) and by age (±4 years). The subjects performed baseline maximal expiratory flow-volume curves (MEFV) and then repeated the same maneuvers through a valve that occluded the air flow 6 times per second with an open/closed time ratio of 4/1. We then plotted an envelope of the expiration-interrupted curve passing through the SF peaks, measured the increase in flow at 50% of the forced vital capacity between the baseline curve and the envelope curves (ΔVmax₅₀), and compared the FEV₁ of the interrupted curve to the FEV₁ obtained from control MEFV curves (ΔFEV₁). Results: We found significantly higher values for ΔVmax₅₀ (p < 0.03) and ΔFEV₁ (p < 0.01) in the asthmatics compared to the COPD patients. Conclusions: The differences reported here are best explained by a greater preservation of elastic recoil pressure at a similar degree of air-flow limitation in the asthmatics than in the COPD patients.

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“…In fact, there is not a single maximal flow-volume curve but rather a family of different curves, which depend on the time course of the inspiration preceding the FVC manoeuvre [35][36][37]. 4) Respiratory mechanics and time constant inequalities are different during the tidal and maximal expiratory efforts, again making comparisons of the two flow-volume curves problematic [38][39][40]. 5) Exercise may result in bronchodilation or bronchoconstriction and other changes of lung mechanics, which may also affect correct comparisons of the two flow-volume curves [41].…”

Section: Conventional (Hyatt's) Methodsmentioning

confidence: 99%

Physiological techniques for detecting expiratory flow limitation during tidal breathing

Koulouris¹,

Hardavella²

2011

Eur Respir Rev

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Patients with severe chronic obstructive pulmonary disease (COPD) often exhale along the same flow-volume curve during quiet breathing as they do during the forced expiratory vital capacity manoeuvre, and this has been taken as an indicator of expiratory flow limitation at rest (EFLT). Therefore, EFLT, namely attainment of maximal expiratory flow during tidal expiration, occurs when an increase in transpulmonary pressure causes no increase in expiratory flow. EFLT leads to small airway injury and promotes dynamic pulmonary hyperinflation, with concurrent dyspnoea and exercise limitation. In fact, EFLT occurs commonly in COPD patients (mainly in Global Initiative for Chronic Obstructive Lung Disease III and IV stage), in whom the latter symptoms are common, but is not exclusive to COPD, since it can also be detected in other pulmonary and nonpulmonary diseases like asthma, acute respiratory distress syndrome, heart failure and obesity, etc. The existing up to date physiological techniques of assessing EFLT are reviewed in the present work. Among the currently available techniques, the negative expiratory pressure has been validated in a wide variety of settings and disorders. Consequently, it should be regarded as a simple, noninvasive, practical and accurate new technique.

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Effect of volume history on successive partial expiratory flow-volume maneuvers

Cited by 33 publications

References 0 publications

A simple method to detect expiratory flow limitation during spontaneous breathing

A simple method to detect expiratory flow limitation during spontaneous breathing

Supramaximal Flows: Comparison between Asthmatics and Patients with Chronic Obstructive Pulmonary Disease

Physiological techniques for detecting expiratory flow limitation during tidal breathing

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