Quantifying the shape of maximal expiratory flow-volume curves in healthy humans and asthmatic patients

Dominelli, Paolo B.; Molgat‐Seon, Yannick; Foster, Glen E.; Dominelli, Giulio S.; Haverkamp, Hans Christian; Henderson, William R.; Sheel, A. William

doi:10.1016/j.resp.2015.09.007

Cited by 10 publications

(21 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their outcomes are in agreement with our recent results (Dominelli et al, 2015) where we utilized the slope-ratio method, as first described by Mead (1978). Collectively, these studies indicate that the shape of the maximal expiratory flow-volume (MEFV) curve has the potential to provide instructive data regarding pathology as well as differences that occur due to normal biological variation (Dominelli et al, 2016). Specifically, both our sets of data demonstrate that the shape of MEFV curves could be used when other metrics (fixed ratio or lower limit of normal) provide conflicting results as to the appropriate diagnosis.…”

supporting

confidence: 90%

Reply to Topalovic and Janssens

Dominelli

Foster

Guenette

et al. 2016

Respiratory Physiology & Neurobiology

Self Cite

View full text Add to dashboard Cite

supporting

confidence: 90%

Reply to Topalovic and Janssens

Dominelli

Foster

Guenette

et al. 2016

Respiratory Physiology & Neurobiology

Self Cite

View full text Add to dashboard Cite

“…The maximum expiratory flow-volume curve depicts the interrelationship between flow and volume during maximum expiration. 11 Slowing of the expiratory flow that results from air-flow obstruction induces a concave shape in the maximum expiratory flow-volume curve during forced exhalation. 12 As determined in a previous study, 13 a concave maximum expiratory flow-volume curve is a sensitive indicator of air-flow limitation and can be detected in subjects with normal values of traditional lung function parameters.…”

Section: Introductionmentioning

confidence: 99%

Curvilinearity of a Maximum Expiratory Flow-Volume Curve: A Useful Indicator for Assessing Airway Obstruction in Children With Asthma

Xiong

Dai²,

et al. 2019

Respir Care

View full text Add to dashboard Cite

BACKGROUND: Lung function parameters are used as signs in the diagnosis and evaluation of asthma; however, their sensitivity and specificity are not ideal. We calculated and combined angle ␤ with lung function parameters to identify the ideal indicator. OBJECTIVE: We aimed to identify an ideal indicator for evaluating the severity of airway obstruction in children with asthma. METHODS: In total, 151 school-age children diagnosed with asthma were selected as the asthma group, and 106 healthy children were selected as the control group. The subjects were divided into the exacerbation group, chronic persistent group, and clinical remission group. Furthermore, the subjects were classified into mild and moderate groups or severe and critical groups. Angle ␤ was calculated in each group. A receiver operating characteristic curve analysis was performed to determine the cutoff values of angle ␤ and lung function parameters that together provided high sensitivity and specificity for airway obstruction evaluation in children with asthma. RESULTS: The mean value of angle ␤ in the asthma group was significantly smaller than that in the control group (178.18°and 196.72°, respectively, P < .001). More exacerbations or greater severity corresponded to smaller angle ␤ values (P < .001). The best cutoff value of angle ␤ was 189.43°, and the area under the receiver operating characteristic curve of angle ␤ was 0.877, which is greater than the area under the receiver operating characteristic curve of FEV 1 , forced expiratory flow (FEF) at 75% vital capacity (FEF 25%), and FEF at 50% vital capacity (FEF 50%), but smaller than the area under the receiver operating characteristic curve of FEF 75% and FEV 1 /FVC%. Interestingly, combining these measures can enhance the sensitivity and specificity in assessing airway obstruction. CONCLUSIONS: Angle ␤ was a useful indicator for assessing airway obstruction. Furthermore, angle ␤ combined with FEV 1 , FEV 1 /FVC%, FEF 25% , FEF 50% , and FEF 75% can enhance the sensitivity and specificity of airway obstruction evaluations.

show abstract

“…Qualitative and quantitative assessment of the descending limb of the FVL and its variability with airway obstruction have already been addressed in past studies, by visual examination or objective measures 13,14,24,24,25 . β‐angle, constructed to transcribe the curvature of the FVL into a single numerical value, 16 is the angle between the first and second half of the FVL at the point of maximum flow point at mid pulmonary volume.…”

Section: Discussionmentioning

confidence: 99%

“…During a forced expiration maneuver, the choke point, where dynamic compression starts, might not be homogeneously distributed in asthmatic lungs, depending on the parallel peripheral resistances. Therefore, whereas healthy lungs will empty uniformly across the forced expired volume, asthmatic lungs will show a successive inhomogeneous emptying of territories, as expected from a model with different time constants, 13 resulting in an upward concavity of FVL. Some indexes were previously described to characterize the shape of FVL 13‐15 .…”

Section: Introductionmentioning

confidence: 92%

“…Therefore, whereas healthy lungs will empty uniformly across the forced expired volume, asthmatic lungs will show a successive inhomogeneous emptying of territories, as expected from a model with different time constants, 13 resulting in an upward concavity of FVL. Some indexes were previously described to characterize the shape of FVL 13‐15 . β‐angle, computed on FVL, is the aperture between two lines passing through forced expiratory flow at 50% of the forced vital capacity (FEF50), one crossing the point at the end of forced expiration corresponding to residual volume, and the other a point situated at the height of peak expiratory flow (PEF) on y axis (Figure 1).…”

Section: Introductionmentioning

confidence: 92%

See 1 more Smart Citation

Assessment of bronchial obstruction and its reversibility by shape indexes of the flow‐volume loop in asthmatic children

Berrier

Tiotiu

Bonabel

et al. 2020

Pediatric Pulmonology

View full text Add to dashboard Cite

Asthma assessment by spirometry is challenging in children as forced expiratory volume in 1 s (FEV1) is frequently normal at baseline. Bronchodilator (BD) reversibility testing may reinforce asthma diagnosis but FEV1 sensitivity in children is controversial. Ventilation inhomogeneity, an early sign of airway obstruction, is described by the upward concavity of the descending limb of the forced expiratory flow-volume loop (FVL), not detected by FEV1. The aim was to test the sensitivity and specificity of FVL shape indexes as β-angle and forced expiratory flow at 50% of the forced vital capacity (FEF50)/peak expiratory flow (PEF) ratio, to identify asthmatics from healthy children in comparison to "usual" spirometric parameters. Seventy-two school-aged asthmatic children and 29 controls were prospectively included. Children performed forced spirometry at baseline and after BD inhalation. Parameters were expressed at baseline as z-scores and BD reversibility as percentage of change reported to baseline value (Δ%). Receiver operating characteristic curves were generated and sensitivity and specificity at respective thresholds reported. Asthmatics presented significantly smaller zβ-angle, zFEF50/PEF and zFEV1 (p ≤ .04) and higher BD reversibility, significant for Δ%FEF50/PEF (p = .02) with no difference for Δ%FEV1. zβ-angle and zFEF50/PEF exhibited better sensitivity (0.58, respectively 0.60) than zFEV1 (0.50), and similar specificity (0.72). Δ%β-angle showed higher sensitivity compared to Δ%FEV1 (0.72 vs. 0.42), but low specificity (0.52 vs. 0.86). Quantitative and qualitative assessment of FVL by adding shape indexes to spirometry interpretation may improve the ability to detect an airway obstruction, FEV1 reflecting more proximal while shape indexes peripheral bronchial obstruction.

show abstract

Quantifying the shape of maximal expiratory flow-volume curves in healthy humans and asthmatic patients

Cited by 10 publications

References 40 publications

Reply to Topalovic and Janssens

Reply to Topalovic and Janssens

Curvilinearity of a Maximum Expiratory Flow-Volume Curve: A Useful Indicator for Assessing Airway Obstruction in Children With Asthma

Assessment of bronchial obstruction and its reversibility by shape indexes of the flow‐volume loop in asthmatic children

Contact Info

Product

Resources

About