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Bartolome R Celli - One of the best experts on this subject based on the ideXlab platform.
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aclidinium bromide improves exercise endurance dyspnea and Inspiratory Capacity in patients with moderate to severe copd
American Thoracic Society International Conference, 2010Co-Authors: François Maltais, Bartolome R Celli, Richard Casaburi, Esther Garcia Gil, Janos Porszasz, Cynthia CaractaAbstract:Rest 0.26�(0.04)*** -0.01�(0.04) 0.24�(0.04)*** 0.01�(0.04) 0.13�(0.05) 0.10�(0.06) Isotime 0.26�(0.04)*** 0.02�(0.04) 0.23�(0.04)** 0.06�(0.04) 0.15�(0.05) 0.10�(0.05) Peak 0.24�(0.04)*** -0.02�(0.04) 0.18�(0.04)* 0.07�(0.04) 0.09�(0.05) 0.08�(0.05) Dyspnea, Borg Rest -0.03�(0.08) 0.12�(0.08) 0.02�(0.09) 0.15�(0.09) 0.01�(0.07) -0.01�(0.07) Isotime -0.58�(0.22)*** 0.56�(0.21) -0.77�(0.21)*** 0.43�(0.21) -0.59�(0.22)* 0.11�(0.22) Peak 0.28�(0.20) 0.44�(0.19) -0.28�(0.22)* 0.37�(0.23) -0.07�(0.20) -0.03�(0.21) Datareportedasmean�(SE). *p<0.05,�**p<0.01,�***p<0.001�vsplacebo;� † Day�-10�datawereusedforbaselinevaluesifDay�-5�datawerenotavailable.�
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Effects of hyperinflation on the oxygen pulse as a marker of cardiac performance in COPD
The European respiratory journal, 2008Co-Authors: Carlos Vassaux, Bartolome R Celli, Luis Torre-bouscoulet, Salah Zeineldine, Felipe Cortopassi, Hildegarde Paz-diaz, Victor Pinto-plataAbstract:A decreased Inspiratory Capacity (IC)/total lung Capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise Capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL·kg−1·min−1) and oxygen pulse (mL·beat−1)) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3–4) and 46 controls. The patients were divided into those with IC/TLC >25% or ≤25%. The IC/TLC ratio at rest and at peak exercise was associated significantly with oxygen pulse. Patients with IC/TLC ≤25% (n = 45) had significantly lower exercise Capacity, peak oxygen pulse, peak minus baseline oxygen pulse, peak IC, peak IC/TLC ratio and % change from baseline to peak IC/TLC ratio compared with patients with IC/TLC >25% and controls. During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC ≤25% than in those with IC/TLC >25%. Resting hyperinflation (Inspiratory Capacity/total lung Capacity) is associated with lower oxygen pulse, peak exercise Inspiratory Capacity/total lung Capacity and exercise Capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.
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Inspiratory to total lung Capacity ratio predicts mortality in patients with chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2005Co-Authors: Ciro Casanova, Juan P De Torres, Victor Pintoplata, A Aguirrejaime, Claudia Cote, Jose M Marin, Bartolome R CelliAbstract:Static lung hyperinflation has important clinical consequences in patients with chronic obstructive pulmonary disease. We analyzed the power of lung hyperinflation as measured by the Inspiratory Capacity–to-total lung Capacity ratio (IC/TLC) to predict mortality in a cohort of 689 patients with chronic obstructive pulmonary disease (95% males; FEV1, 1.17 L) with a mean follow-up of 34 months. We also compared the predictive value of IC/TLC with that of the BODE (body mass index, airflow obstruction, dyspnea, exercise performance) Index. Subjects who died (183; 27%) were older; had lower body mass index, FEV1, and IC/TLC ratio; walked less in the 6-minute walking distance; and had more dyspnea, a higher BODE Index, and comorbidity (p < 0.001). On the basis of logistic regression analysis, IC/TLC was found to be a good and independent predictor of all-cause and respiratory mortality. On the basis of receiver operating characteristic Type II curves, IC/TLC compared favorably with FEV1 and predicted mortality...
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Inspiratory to total lung Capacity ratio predicts mortality in patients with chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2005Co-Authors: Ciro Casanova, Juan P De Torres, Victor Pintoplata, A Aguirrejaime, Claudia Cote, Jose M Marin, Bartolome R CelliAbstract:Static lung hyperinflation has important clinical consequences in patients with chronic obstructive pulmonary disease. We analyzed the power of lung hyperinflation as measured by the Inspiratory Capacity–to-total lung Capacity ratio (IC/TLC) to predict mortality in a cohort of 689 patients with chronic obstructive pulmonary disease (95% males; FEV1, 1.17 L) with a mean follow-up of 34 months. We also compared the predictive value of IC/TLC with that of the BODE (body mass index, airflow obstruction, dyspnea, exercise performance) Index. Subjects who died (183; 27%) were older; had lower body mass index, FEV1, and IC/TLC ratio; walked less in the 6-minute walking distance; and had more dyspnea, a higher BODE Index, and comorbidity (p < 0.001). On the basis of logistic regression analysis, IC/TLC was found to be a good and independent predictor of all-cause and respiratory mortality. On the basis of receiver operating characteristic Type II curves, IC/TLC compared favorably with FEV1 and predicted mortality...
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improvement in resting Inspiratory Capacity and hyperinflation with tiotropium in copd patients with increased static lung volumes
Chest, 2003Co-Authors: Bartolome R Celli, Richard Zuwallack, Susan Wang, Steven KestenAbstract:Background: In patients with COPD, changes in Inspiratory Capacity (IC) have shown a higher correlation to patient-focused outcomes, such as dyspnea with exercise, than other standard spirometric measurements. Changes in IC reflect changes in hyperinflation. Tiotropium is a once-daily inhaled anticholinergic that has its effect through prolonged M3 muscarinic receptor antagonism and has demonstrated sustained improvements in spirometric and health outcomes. We sought to evaluate changes in resting IC and lung volumes after long-term administration of tiotropium. Methods: To evaluate the effect of tiotropium, 18 g/d, on IC, a 4-week, randomized, doubleblind, placebo-controlled study was conducted in 81 patients with stable COPD. At each of the visits (weeks 0, 2, and 4) FEV1, FVC, IC, slow vital Capacity (SVC), and thoracic gas volume (TGV) were measured prior to study drug (– 60 and – 15 min) and after study drug (30 min, 60 min, 120 min, and 180 min). Results: Mean age was 64 years; 62% were men. Mean baseline FEV1 was 1.12 L (43% predicted). The mean differences (tiotropium placebo) in FEV1 trough (morning before drug), peak, and area under the curve over 3 h values (adjusted for baseline and center differences) at week 4 were 0.16 L, 0.22 L, and 0.22 L, respectively (p < 0.01 for all); differences in IC for these variables were 0.22 L, 0.35 L, and 0.30 L (p < 0.01 for all). Differences in TGV were – 0.54 L, – 0.60 L, and – 0.70 L, respectively (p < 0.01 for all). The percentage improvement in area under the curve above baseline with tiotropium was similar among FEV1 and lung volumes (FEV1, 18%; FVC, 20%; SVC, 16%; IC, 16%; TGV, 14%). Conclusions: Observed improvements in IC and reductions in TGV with once-daily tiotropium reflect improvements in hyperinflation that are maintained over 24 h. (CHEST 2003; 124:1743–1748)
Denis E Odonnell - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of orthopnea in patients with advanced copd
European Respiratory Journal, 2019Co-Authors: Amany F Elbehairy, Azmy Faisal, Hannah Mcisaac, Casey E Ciavaglia, Alberto J Neder, Denis E OdonnellAbstract:Background: Many patients with COPD report unpleasant respiratory sensation at rest, further amplified by adoption of supine position (orthopnea). The source of this sensation remains poorly understood. Methods: 16 symptomatic patients with advanced COPD and 16 age- and gender-matched healthy controls (CTRL) underwent pulmonary function tests and detailed sensory-mechanical measurements with diaphragm electromyography (EMGdi) and respiratory pressures in sitting and supine positions. Results: Patients (age:66±7years, BMI:25±6 Kg/m2, smoking history:52±25 pack-year, FEV1:40±18 %predicted) had lower Inspiratory Capacity (IC) by 44% and greater intensity of breathing difficulty (Borg scale) compared with CTRL (p Conclusion: In COPD, acute orthopnea while supine coincided with an abrupt increase in amplitude of diaphragm activation and force generation in the setting of a low fixed Inspiratory Capacity.
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the link between reduced Inspiratory Capacity and exercise intolerance in chronic obstructive pulmonary disease
Annals of the American Thoracic Society, 2017Co-Authors: Denis E Odonnell, Amany F Elbehairy, Katherine A Webb, J A NederAbstract:Low Inspiratory Capacity (IC), chronic dyspnea, and reduced exercise Capacity are inextricably linked and are independent predictors of increased mortality in chronic obstructive pulmonary disease. It is no surprise, therefore, that a major goal of management is to improve IC by reducing lung hyperinflation to improve respiratory symptoms and health-related quality of life. The negative effects of lung hyperinflation on respiratory muscle and cardiocirculatory function during exercise are now well established. Moreover, there is growing appreciation that a key mechanism of exertional dyspnea in chronic obstructive pulmonary disease is critical mechanical constraints on tidal volume expansion during exercise when resting IC is reduced. Further evidence for the importance of lung hyperinflation comes from multiple studies, which have reported the clinical benefits of therapeutic interventions that reduce lung hyperinflation and increase IC. A reduced IC in obstructive pulmonary disease is further eroded by ...
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effects of combined tiotropium olodaterol on Inspiratory Capacity and exercise endurance in copd
European Respiratory Journal, 2017Co-Authors: Denis E Odonnell, Annemarie Kirsten, Dorothy De Sousa, Peter Frith, Richard Casaburi, Alan Hamilton, François MaltaisAbstract:Two replicate, double-blind, 6-week, incomplete-crossover studies (MORACTO 1 and 2) assessed the effects of tiotropium/olodaterol on Inspiratory Capacity and exercise endurance time in patients with moderate to severe chronic obstructive pulmonary disease. For each patient, four of five treatments were administered once daily for 6 weeks, with a 21-day washout between treatments: tiotropium/olodaterol 2.5/5 µg or 5/5 µg, tiotropium 5 µg, olodaterol 5 µg or placebo, all via the Respimat inhaler. Primary outcomes were Inspiratory Capacity prior to exercise and exercise endurance time during constant work-rate cycle ergometry to symptom limitation at 75% of peak incremental work rate after 6 weeks (2 h post-dose). 295 and 291 patients were treated in MORACTO 1 and 2, respectively. Tiotropium/olodaterol 2.5/5 and 5/5 µg provided significant improvements in Inspiratory Capacity versus placebo and monotherapies (p versus placebo (p versus placebo (p Once-daily tiotropium/olodaterol yielded improvements in lung hyperinflation versus placebo and statistically significant improvements versus monotherapies. Tiotropium/olodaterol also showed improvements in dyspnoea and exercise tolerance versus placebo but not consistently versus monotherapies.
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common mechanisms of dyspnea in chronic interstitial and obstructive lung disorders
American Journal of Respiratory and Critical Care Medicine, 2016Co-Authors: Azmy Faisal, Amany F Elbehairy, Casey E Ciavaglia, Alberto J Neder, Katherine A Webb, Bader J Alghamdi, Josuel Ora, Denis E OdonnellAbstract:Rationale: The mechanisms underlying dyspnea in interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD) are unknown.Objectives: To examine whether the relationship between Inspiratory neural drive to the diaphragm and exertional dyspnea intensity is different in ILD and COPD, given the marked differences in static respiratory mechanics between these conditions.Methods: We compared sensory–mechanical relationships in patients with ILD, patients with COPD, and healthy control subjects (n = 16 each) during incremental cycle exercise with diaphragmatic electromyography (EMGdi) and respiratory pressure measurements.Measurements and Main Results: In patients with mild to moderate ILD or COPD with similarly reduced Inspiratory Capacity, the peak oxygen uptake, work rate, and ventilation were lower (P < 0.05) than in healthy control subjects. EMGdi expressed as a percentage of the maximum (EMGdi/EMGdi,max), respiratory effort (esophageal pressure expressed as percentage of the maximum), a...
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decline of resting Inspiratory Capacity in copd the impact on breathing pattern dyspnea and ventilatory Capacity during exercise
Chest, 2012Co-Authors: Denis E Odonnell, François Maltais, Jordan A Guenette, Katherine A WebbAbstract:Background To better understand the interrelationships among disease severity, Inspiratory Capacity (IC), breathing pattern, and dyspnea, we studied responses to symptom-limited cycle exercise in a large cohort with COPD. Methods Analysis was conducted on data from two previously published replicate clinical trials in 427 hyperinflated patients with COPD. Patients were divided into disease severity quartiles based on FEV 1 % predicted. Spirometry, plethysmographic lung volumes, and physiologic and perceptual responses to constant work rate (CWR) cycle exercise at 75% of the peak incremental work rate were compared. Results Age, body size, and COPD duration were similar across quartiles. As the FEV 1 quartile worsened (mean, 62%, 49%, 39%, and 27% predicted), functional residual Capacity increased (144%, 151%, 164%, and 185% predicted), IC decreased (86%, 81%, 69%, and 60% predicted), and peak incremental cycle work rate decreased (66%, 55%, 50%, and 44% predicted); CWR endurance time was 9.7, 9.3, 8.2, and 7.3 min, respectively. During CWR exercise, as FEV 1 quartile worsened, peak minute ventilation ( e ) and tidal volume (V t ) decreased, whereas an inflection or plateau of the V t response occurred at a progressively lower e ( P e (82%–86%), and similar V t /IC ratio (73%–77%). Dyspnea intensity at this inflection point was also similar across quartiles (3.1-3.7 Borg units) but accelerated steeply to intolerable levels thereafter. Conclusion Progressive reduction of the resting IC with increasing disease severity was associated with the appearance of critical constraints on V t expansion and a sharp increase in dyspnea to intolerable levels at a progressively lower ventilation during exercise.
Franco Laghi - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Breathing Retraining Using Metronome-Based Acoustic Feedback on Exercise Endurance in COPD: A Randomized Trial
Lung, 2019Co-Authors: Eileen G. Collins, Christine Jelinek, Susan O’connell, Jolene Butler, Domenic Reda, Franco LaghiAbstract:Background During exercise-training patients with chronic obstructive pulmonary disease (COPD) can entrain their breathing pattern to visual-feedback cues as to achieve a slower respiratory rate and prolong exhalation. The result is an improvement in exercise tolerance and a reduction in dynamic hyperinflation. Acoustic stimuli, including metronome-generated acoustic stimuli, can entrain human movements. Accordingly, we hypothesized that exercise duration and dynamic hyperinflation would be less after exercise-training plus breathing-retraining using a metronome-based acoustic-feedback system than after exercise-training alone. Methods Of 205 patients with COPD [FEV_1 = 44 ± 16% predicted (± SD)] recruited, 119 were randomly assigned to exercise-training plus breathing-retraining using acoustic feedback ( n = 58) or exercise-training alone ( n = 61). Patients exercised on a treadmill thrice-weekly for 12 weeks. Before and at completion of training, patients underwent constant-load treadmill testing with Inspiratory Capacity measures every 2 min. Results At completion of training, improvements in exercise duration in the breathing-retraining plus exercise-training and exercise-training alone groups were similar ( p = 0.35). At isotime, Inspiratory Capacity increased (less exercise-induced dynamic hyperinflation) by 3% ( p = 0.001) in the breathing-retraining plus exercise-training group and remained unchanged in the exercise-alone group. The between-group change in Inspiratory Capacity, however, was not significant ( p = 0.08). Conclusions In patients with COPD, breathing-retraining using a metronome-based acoustic feedback did not result in improved exercise endurance or decreased dynamic hyperinflation when compared to exercise-training alone. Trial registry : ClinicalTrials.gov; No.: NCT NCT01009099; URL: http://www.clinicaltrials.gov
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the effect of breathing retraining using metronome based acoustic feedback on exercise endurance in copd a randomized trial
Lung, 2019Co-Authors: Eileen G. Collins, Christine Jelinek, Jolene Butler, Franco Laghi, Susan Oconnell, Domenic J RedaAbstract:During exercise-training patients with chronic obstructive pulmonary disease (COPD) can entrain their breathing pattern to visual-feedback cues as to achieve a slower respiratory rate and prolong exhalation. The result is an improvement in exercise tolerance and a reduction in dynamic hyperinflation. Acoustic stimuli, including metronome-generated acoustic stimuli, can entrain human movements. Accordingly, we hypothesized that exercise duration and dynamic hyperinflation would be less after exercise-training plus breathing-retraining using a metronome-based acoustic-feedback system than after exercise-training alone. Of 205 patients with COPD [FEV1 = 44 ± 16% predicted (± SD)] recruited, 119 were randomly assigned to exercise-training plus breathing-retraining using acoustic feedback (n = 58) or exercise-training alone (n = 61). Patients exercised on a treadmill thrice-weekly for 12 weeks. Before and at completion of training, patients underwent constant-load treadmill testing with Inspiratory Capacity measures every 2 min. At completion of training, improvements in exercise duration in the breathing-retraining plus exercise-training and exercise-training alone groups were similar (p = 0.35). At isotime, Inspiratory Capacity increased (less exercise-induced dynamic hyperinflation) by 3% (p = 0.001) in the breathing-retraining plus exercise-training group and remained unchanged in the exercise-alone group. The between-group change in Inspiratory Capacity, however, was not significant (p = 0.08). In patients with COPD, breathing-retraining using a metronome-based acoustic feedback did not result in improved exercise endurance or decreased dynamic hyperinflation when compared to exercise-training alone. Trial registry: ClinicalTrials.gov; No.: NCT NCT01009099; URL: http://www.clinicaltrials.gov
C Lisboa - One of the best experts on this subject based on the ideXlab platform.
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breathing pattern and gas exchange at peak exercise in copd patients with and without tidal flow limitation at rest
European Respiratory Journal, 2001Co-Authors: Orlando Diaz, J Milicemili, C Villafranca, H Ghezzo, Gisella R Borzone, A Leiva, C LisboaAbstract:Expiratory flow limitation (FL) at rest is frequently present in chronic obstructive pulmonary disease (COPD) patients. It promotes dynamic hyperinflation with a consequent decrease in Inspiratory Capacity (IC). Since in COPD resting IC is strongly correlated with exercise tolerance, this study hypothesized that this is due to limitation of the maximal tidal volume ( V T,max) during exercise by the reduced IC. The present study investigated the role of tidal FL at rest on: 1) the relationship of resting IC to V T,max; and 2) on gas exchange during peak exercise in COPD patients. Fifty-two stable COPD patients were studied at rest, using the negative expiratory pressure technique to assess the presence of FL, and during incremental symptom-limited cycling exercise to evaluate exercise performance. At rest, FL was present in 29 patients. In the 52 patients, a close relationship of V T,max to IC was found using non-normalized values (r=0.77; p<0.0001), and stepwise regression analysis selected IC as the only significant predictor of V T,max. Subgroup analysis showed that this was also the case for patients both with and without FL (r=0.70 and 0.76, respectively). In addition, in FL patients there was an increase (p<0.002) in arterial carbon dioxide partial pressure at peak exercise, mainly due to a relatively low V T,max and consequent increase in the physiological dead space ( V D)/ V T ratio. The arterial oxygen partial pressure also decreased at peak exercise in the FL patients (p<0.05). In conclusion, in chronic obstructive pulmonary disease patients the maximal tidal volume, and hence maximal oxygen consumption, are closely related to the reduced Inspiratory Capacity. The flow limited patients also exhibit a significant increase in arterial carbon dioxide partial pressure and a decrease in arterial oxygen partial pressure during peak exercise. This study was supported by Grant 198/0937 from Fondecyt.
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role of Inspiratory Capacity on exercise tolerance in copd patients with and without tidal expiratory flow limitation at rest
European Respiratory Journal, 2000Co-Authors: Orlando Diaz, C Villafranca, H Ghezzo, Gisella R Borzone, A Leiva, J Milicemil, C LisboaAbstract:Expiratory flow limitation promotes dynamic hyperinflation during exercise in chronic obstructive pulmonary disease (COPD) patients with a consequent reduction in Inspiratory Capacity (IC), limiting their exercise tolerance. Therefore, the exercise Capacity of patients with tidal expiratory flow limitation (FL) at rest should depend on the magnitude of IC. The presented study was designed to evaluate the role of FL on the relationship between resting IC, other respiratory function variables and exercise performance in COPD patients. Fifty-two patients were included in the study. Negative expiratory pressure (NEP) uptake (VO2,max) were measured during an incremental symptom-limited cycle exercise. Twenty-nine patients were FL at rest. The IC was normal in all non-FL patients, while in most FL subjects it was decreased. Both WRmax and VO2,max were lower in FL patients (p<0.001, each). A close relationship of WRmax and O2,max to IC was found (r=0.73 and 0.75, respectively; p<0.0001, each). In the whole group, stepwise regression analysis selected IC and forced expiratory volume in one second (FEV1)/forced vital Capacity (FVC) (% predicted) as the only significant contributors to exercise tolerance. Subgroup analysis showed that IC was the sole predictor in FL patients, and FEV1/FVC in non-FL patients. Detection of flow limitation provides useful information on the factors that influence exercise Capacity in chronic obstructive pulmonary disease patients. Accordingly, in patients with flow limitation, Inspiratory Capacity appears as the best predictor of exercise tolerance, reflecting the presence of dynamic hyperinflation.
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role of Inspiratory Capacity on exercise tolerance in copd patients with and without tidal expiratory flow limitation at rest
European Respiratory Journal, 2000Co-Authors: Orlando Diaz, C Villafranca, H Ghezzo, Gisella R Borzone, A Leiva, J Milicemil, C LisboaAbstract:Expiratory flow limitation promotes dynamic hyperinflation during exercise in chronic obstructive pulmonary disease (COPD) patients with a consequent reduction in Inspiratory Capacity (IC), limiting their exercise tolerance. Therefore, the exercise Capacity of patients with tidal expiratory flow limitation (FL) at rest should depend on the magnitude of IC. The presented study was designed to evaluate the role of FL on the relationship between resting IC, other respiratory function variables and exercise performance in COPD patients. Fifty-two patients were included in the study. Negative expiratory pressure (NEP) uptake (VO2,max) were measured during an incremental symptom-limited cycle exercise. Twenty-nine patients were FL at rest. The IC was normal in all non-FL patients, while in most FL subjects it was decreased. Both WRmax and VO2,max were lower in FL patients (p
Katherine A Webb - One of the best experts on this subject based on the ideXlab platform.
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the link between reduced Inspiratory Capacity and exercise intolerance in chronic obstructive pulmonary disease
Annals of the American Thoracic Society, 2017Co-Authors: Denis E Odonnell, Amany F Elbehairy, Katherine A Webb, J A NederAbstract:Low Inspiratory Capacity (IC), chronic dyspnea, and reduced exercise Capacity are inextricably linked and are independent predictors of increased mortality in chronic obstructive pulmonary disease. It is no surprise, therefore, that a major goal of management is to improve IC by reducing lung hyperinflation to improve respiratory symptoms and health-related quality of life. The negative effects of lung hyperinflation on respiratory muscle and cardiocirculatory function during exercise are now well established. Moreover, there is growing appreciation that a key mechanism of exertional dyspnea in chronic obstructive pulmonary disease is critical mechanical constraints on tidal volume expansion during exercise when resting IC is reduced. Further evidence for the importance of lung hyperinflation comes from multiple studies, which have reported the clinical benefits of therapeutic interventions that reduce lung hyperinflation and increase IC. A reduced IC in obstructive pulmonary disease is further eroded by ...
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Review Article Inspiratory Capacity during Exercise: Measurement, Analysis, and Interpretation
2016Co-Authors: Jordan A Guenette, Katherine A Webb, Roberto C. Chin, Julia M. Cory, Denis E. O’donnellAbstract:Copyright © 2013 Jordan A. Guenette et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Cardiopulmonary exercise testing (CPET) is an established method for evaluating dyspnea and ventilatory abnormalities. Ventilatory reserve is typically assessed as the ratio of peak exercise ventilation to maximal voluntary ventilation. Unfortunately, this crude assessment provides limited data on the factors that limit the normal ventilatory response to exercise. Additional measurements can provide a more comprehensive evaluation of respiratory mechanical constraints during CPET (e.g., expiratory flow limitation and operating lung volumes). These measurements are directly dependent on an accurate assessment of Inspiratory Capacity (IC) throughout rest and exercise. Despite the valuable insight that the IC provides, there are no established recommendations on how to perform the maneuver during exercise and how to analyze and interpret the data. Accordingly, the purpose of this manuscript is to comprehensively examine a number of methodological issues related to themeasurement, analysis, and interpretation of the IC. We will also briefly discuss IC responses to exercise in health and disease and will consider how various therapeutic interventions influence the IC, particularly in patients with chronic obstructive pulmonary disease. Our main conclusion is that IC measurements are both reproducible and responsive to therapy and provide important information on th
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common mechanisms of dyspnea in chronic interstitial and obstructive lung disorders
American Journal of Respiratory and Critical Care Medicine, 2016Co-Authors: Azmy Faisal, Amany F Elbehairy, Casey E Ciavaglia, Alberto J Neder, Katherine A Webb, Bader J Alghamdi, Josuel Ora, Denis E OdonnellAbstract:Rationale: The mechanisms underlying dyspnea in interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD) are unknown.Objectives: To examine whether the relationship between Inspiratory neural drive to the diaphragm and exertional dyspnea intensity is different in ILD and COPD, given the marked differences in static respiratory mechanics between these conditions.Methods: We compared sensory–mechanical relationships in patients with ILD, patients with COPD, and healthy control subjects (n = 16 each) during incremental cycle exercise with diaphragmatic electromyography (EMGdi) and respiratory pressure measurements.Measurements and Main Results: In patients with mild to moderate ILD or COPD with similarly reduced Inspiratory Capacity, the peak oxygen uptake, work rate, and ventilation were lower (P < 0.05) than in healthy control subjects. EMGdi expressed as a percentage of the maximum (EMGdi/EMGdi,max), respiratory effort (esophageal pressure expressed as percentage of the maximum), a...
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decline of resting Inspiratory Capacity in copd the impact on breathing pattern dyspnea and ventilatory Capacity during exercise
Chest, 2012Co-Authors: Denis E Odonnell, François Maltais, Jordan A Guenette, Katherine A WebbAbstract:Background To better understand the interrelationships among disease severity, Inspiratory Capacity (IC), breathing pattern, and dyspnea, we studied responses to symptom-limited cycle exercise in a large cohort with COPD. Methods Analysis was conducted on data from two previously published replicate clinical trials in 427 hyperinflated patients with COPD. Patients were divided into disease severity quartiles based on FEV 1 % predicted. Spirometry, plethysmographic lung volumes, and physiologic and perceptual responses to constant work rate (CWR) cycle exercise at 75% of the peak incremental work rate were compared. Results Age, body size, and COPD duration were similar across quartiles. As the FEV 1 quartile worsened (mean, 62%, 49%, 39%, and 27% predicted), functional residual Capacity increased (144%, 151%, 164%, and 185% predicted), IC decreased (86%, 81%, 69%, and 60% predicted), and peak incremental cycle work rate decreased (66%, 55%, 50%, and 44% predicted); CWR endurance time was 9.7, 9.3, 8.2, and 7.3 min, respectively. During CWR exercise, as FEV 1 quartile worsened, peak minute ventilation ( e ) and tidal volume (V t ) decreased, whereas an inflection or plateau of the V t response occurred at a progressively lower e ( P e (82%–86%), and similar V t /IC ratio (73%–77%). Dyspnea intensity at this inflection point was also similar across quartiles (3.1-3.7 Borg units) but accelerated steeply to intolerable levels thereafter. Conclusion Progressive reduction of the resting IC with increasing disease severity was associated with the appearance of critical constraints on V t expansion and a sharp increase in dyspnea to intolerable levels at a progressively lower ventilation during exercise.
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lung hyperinflation and its reversibility in patients with airway obstruction of varying severity
COPD: Journal of Chronic Obstructive Pulmonary Disease, 2010Co-Authors: Athavudh Deesomchok, Katherine A Webb, Yukmiu Lam, Lutz Forkert, Dror Ofir, Dennis Jensen, Denis E OdonnellAbstract:ABSTRACTThe natural history of lung hyperinflation in patients with airway obstruction is unknown. In particular, little information exists about the extent of air trapping and its reversibility to bronchodilator therapy in those with mild airway obstruction. We completed a retrospective analysis of data from individuals with airway obstruction who attended our pulmonary function laboratory and had plethysmographic lung volume measurements pre- and post-bronchodilator (salbutamol). COPD was likely the predominant diagnosis but patients with asthma may have been included. We studied 2,265 subjects (61% male), age 65 ± 9 years (mean ± SD) with a post-bronchodilator FEV1/FVC <0.70. We examined relationships between indices of airway obstruction and lung hyperinflation, and measured responses to bronchodilation across subgroups stratified by GOLD criteria. In GOLD stage I, vital Capacity (VC) and Inspiratory Capacity (IC) were in the normal range; pre-bronchodilator residual volume (RV), functional residual c...