Analysis of Tidal Breathing Profiles in Cystic Fibrosis and COPD

Colasanti, R. L.; Morris, MJ; Madgwick, Richard G.; Sutton, Linda; Williams, Edgar M.

doi:10.1378/chest.125.3.901

Cited by 24 publications

(36 citation statements)

References 14 publications

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“…Morris et al 3,4 and Colasanti et al 19 noted that the reason for SEFV curve concavity was dynamic airway compression or gas compression by high pleural pressure during expiration. These changes appear to affect the forced expiratory volume (FEV) curve pattern, but not the SEFV curve pattern in patients with moderate or severe COPD, but they affect the SEFV curve pattern (not only FEV) in patients with very severe COPD.…”

Section: Resultsmentioning

confidence: 99%

Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients

Nozoe¹,

Mase

Murakami³

et al. 2013

Respir Care

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BACKGROUND: Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of airflow obstruction in elderly COPD patients. METHODS: In 34 elderly subjects (mean ؎ SD age 80 ؎ 7 y) with stable COPD (percent-of-predicted FEV 1 39.0 ؎ 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. RESULTS: Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV 1 % (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83-1.00), and had the highest sensitivity (0.93) and specificity (0.88). CONCLUSIONS: Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients unable to perform a satisfactory FVC maneuver.

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Section: Resultsmentioning

confidence: 99%

Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients

Nozoe¹,

Mase

Murakami³

et al. 2013

Respir Care

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“…Observed changes in the severity of breathlessness and declining pulmonary function should alter resting tidal breathing . Despite this, little is known about changes to the pattern of tidal breathing in this patient group, and whether tidal breathing relates to other measures of disease progression and breathlessness severity.…”

Section: Introductionmentioning

confidence: 99%

Breathing pattern and breathlessness in idiopathic pulmonary fibrosis: An observational study

et al. 2015

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Background and objective: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive decline in lung function and increasing dyspnoea. The aim of this study was to investigate the relationship among IPF, pulmonary function, resting tidal breathing patterns and level of breathlessness. Methods: Thirty-one participants with IPF and 17 matched healthy controls underwent lung function testing, followed by a 2-min period of resting tidal breathing. The IPF cohort was stratified according to disease severity, based on their forced vital capacity and diffusion capacity for carbon monoxide. Results: In comparison to the healthy controls, the IPF cohort showed a higher tidal volume, VT, of 0.22 L (P = 0.026) and a raised minute ventilation in the severest IPF group, while no differences in the timing of inspiration or expiration were observed. In the IPF cohort, the ratio of VT to forced vital capacity was around 15% higher. These changes corresponded with an increase in the self-reported sensation of breathlessness. Conclusion: Those with IPF increased their depth of breathing with worsening disease severity, with IPF-induced changes in pulmonary function and breath-lessness associated with an altered tidal breathing pattern.

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“…It would be highly desirable to predict respiratory volume and flow signal waveforms accurately during tidal breathing as, because they contain pathological signs, for example, of asthma [12], airway obstruction [13-15], cystic fibrosis [16], and chronic obstructive pulmonary disease [17]. However, the respiratory volume and respiratory flow accuracy are degraded with subject body position or breathing style change due to the change of calibration factors [18].…”

Section: Introductionmentioning

confidence: 99%

Reducing the airflow waveform distortions from breathing style and body position with improved calibration of respiratory effort belts

2013

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BackgroundRespiratory effort belt measurement is a widely used method to monitor respiration. Signal waveforms of respiratory volume and flow may indicate pathological signs of several diseases and, thus, it would be highly desirable to predict them accurately. Calibrated effort belts are sufficiently accurate for estimating respiratory rate, but the respiratory volume and flow prediction accuracies degrade considerably with changes in the subject’s body position and breathing style.MethodsAn improved calibration method of respiratory effort belts is presented in this paper. It is based on an optimally trained FIR (Finite Impulse Response) filter bank constructed as a MISO system (Multiple-Input Single-Output) between respiratory effort belt signals and the spirometer in order to reduce waveform errors. Ten healthy adult volunteers were recruited. Breathing was varied between the following styles: metronome-guided controlled breathing rate of 0.1 Hz, 0.15 Hz, 0.25 Hz and 0.33 Hz, and a free rate that was felt normal by each subject. Body position was varied between supine, sitting and standing. The proposed calibration method was tested against these variations and compared with the state-of-the-art methods from the literature.ResultsRelative waveform error decreased 60-70% when predicting airflow under changing breathing styles. The coefficient of determination R2 varied between 0.88-0.95 and 0.65-0.79 with the proposed and the standard method, respectively. Standard deviation of respiratory volume error decreased even 80%. The proposed method outperformed other methods.ConclusionsResults show that not only the respiratory volume can be computed more precisely from the predicted airflow, but also the flow waveforms are very accurate with the proposed method. The method is robust to breathing style changes and body position changes improving greatly the accuracy of the calibration of respiratory effort belts over the standard method. The enhanced accuracy of the belt calibration offers interesting opportunities, e.g. in pulmonary and critical care medicine when objective measurements are required.

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Analysis of Tidal Breathing Profiles in Cystic Fibrosis and COPD

Cited by 24 publications

References 14 publications

Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients

Relationship Between Spontaneous Expiratory Flow-Volume Curve Pattern and Air-Flow Obstruction in Elderly COPD Patients

Breathing pattern and breathlessness in idiopathic pulmonary fibrosis: An observational study

Reducing the airflow waveform distortions from breathing style and body position with improved calibration of respiratory effort belts

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