Sources of variation in FEV1.

Coates, Allan L.; Desmond, Katharine J.; Demizio, Debbie; Allen, Paul D.

doi:10.1164/ajrccm.149.2.8306042

Cited by 24 publications

(13 citation statements)

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“…In contrast, our data support the notion that the opposite is true (table 3). In addition, although FEV1 is much less dependent on effort than had been originally thought [14], provided that the FVC manoeuvre fulfils the ATS criteria [15,16], it is also significantly different. Consequently, while the increase in PEF could, in part, be related to greater expiratory muscle activation, muscle activation alone is unlikely to explain the higher FEV1, MMEF, and MEF25, MEF50 and MEF75 found with manoeuvre 1 [2][3][4].…”

Section: Discussionmentioning

confidence: 84%

Dependence of forced vital capacity manoeuvre on time course of preceding inspiration in patients with restrictive lung disease

Koulouris¹,

Rapakoulias²,

Rassidakis³

et al. 1997

Eur Respir J

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In normal subjects and patients with airway obstruction, flows during a forced vital capacity (FVC) manoeuvre are higher after a fast inspiration without an end-inspiratory pause (manoeuvre 1) as compared to a slow inspiration with an end-expiratory pause of ~5 s (manoeuvre 2). In this study, we investigated the influence of these manoeuvres on maximal expiratory volume-time and flow-volume curves in patients with restrictive lung disease.Eleven patients with restrictive lung disease were studied. Their average (±SD) lung function test results were: FVC=55±12% predicted value, forced expiratory volume in one second (FEV1) 52±20% pred, FEV1/FVC 85±6%, total lung capacity 55±8% pred, and carbon monoxide transfer factor 47±18% pred. The patients performed the two FVC manoeuvres in random order. We compared the ensuing spirograms and maximal expiratory flow-volume curves from which peak expiratory flow, FEV1, FEV1/FVC, maximal mid-expiratory flow, and maximal flows were computed.All spirometric indices were significantly higher with manoeuvre 1 than 2. Maximal expiratory flows at the same lung volume were also significantly higher with manoeuvre 1 than 2, in all patients.Routine spirometric indices, obtained during a forced vital capacity manoeuvre depend on the time course of the preceding inspiration in patients with restrictive lung disease. Therefore, the forced vital capacity manoeuvre should be standardized if used in clinical, epidemiological and research studies.

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Section: Discussionmentioning

confidence: 84%

Dependence of forced vital capacity manoeuvre on time course of preceding inspiration in patients with restrictive lung disease

Koulouris¹,

Rapakoulias²,

Rassidakis³

et al. 1997

Eur Respir J

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“…It is likely that the intraindividual variation of repeated measurements [13] was too high for most of the function indices to appreciate the small systematic differences introduced by the Spirobac filter. In routine laboratory activity, the measurement error is presumably higher than in our study and, therefore, systematic differences due to the filter should be less likely to be detected [13,14].…”

Section: Discussionmentioning

confidence: 91%

Effects of a filter at the mouth on pulmonary function tests

Fuso¹,

Accardo²,

Bevignani³

et al. 1995

Eur Respir J

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E Ef ff fe ec ct ts s o of f a a f fi il lt te er r a at t t th he e m mo ou ut th h o on n p pu ul lm mo on na ar ry y f fu un nc ct ti io on n t te es st ts sL. Fuso*, D. Accardo*, G. Bevignani*, E. Ferrante**, A. Della Corte*, R. Pistelli* Effects of a filter at the mouth on pulmonary function tests. L. Fuso, D. Accardo, G. Bevignani, E. Ferrante, A. Della Corte, R. Pistelli. ERS Journals Ltd 1995. ABSTRACT: The aim of this study was to verify whether the increase of resistance to airflow using a filter at the mouth could determine significant systematic errors of measurement or change the diagnostic performance in a respiratory physiology laboratory.The effect of the new filter Spirobac (DAR Spa, Italy) was assessed on out-patients referred to our laboratory for routine functional evaluation. The following tests were performed: maximal expiratory flow-volume curve, plethysmographic lung volume and airway resistance, bronchodilator test, and methacholine challenge test. Each test was performed randomly, twice with the filter and twice without.Significant differences between measurements with and without filter were found for forced vital capacity, forced expiratory volume in one second, airway resistance, and specific airway conductance (sGaw). These differences were unrelated to the average values of the measurements, except for sGaw. The limits of agreement were within the range of intraindividual short-term repeatability for almost all of the function indices. The overall concordance between tests performed with and without filter was 78% for bronchodilator test and 53% for methacholine test. However, in all the cases but one, the concordance of the methacholine test was inside the short-term repeatability.We conclude that the filter Spirobac has a statistically significant effect on the results of some pulmonary function tests. However, this is not considered to be clinically significant, since the changes due to the filter were within the intraindividual variability of repeated measurements for almost all the function indices and no appreciable classification error was found in diagnostic tests.

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“…The short-term (, 1 h) within-subject reproducibility for FEV 1 and FVC is very good: less than or equal to 200 ml and 5% for both healthy subjects and patients with asthma (all ages) (144,145). Values within these limits are indicative of acceptable biological and technical variability.…”

Section: Lung Function and Airway Hyperresponsiveness Spirometrymentioning

confidence: 90%