Kinetic analyses as a tool to examine physiological exercise responses in a large sample of patients with COPD

2020 ◽  
Vol 128 (4) ◽  
pp. 813-821
Author(s):  
Joren Buekers ◽  
Jean-Marie Aerts ◽  
Jan Theunis ◽  
Sarah Houben-Wilke ◽  
Frits M. E. Franssen ◽  
...  
Keyword(s):  
Work Rate ◽  
Chronic Obstructive ◽  
Kinetic Feature ◽  
Obstructive Pulmonary Disease ◽  
Mean Response Time ◽  
Copd Patients ◽  
Constant Work Rate ◽  
Rate Test ◽  
Feature Values ◽  
Kinetic Features

Kinetic features such as oxygen uptake (V̇o2) mean response time (MRT), and gains of V̇o2, carbon dioxide output (V̇co2), and minute ventilation (V̇e) can describe physiological exercise responses during a constant work rate test of patients with chronic obstructive pulmonary disease (COPD). This study aimed to establish simple guidelines that can identify COPD patients for whom kinetic analyses are (un)likely to be reliable and examined whether slow V̇o2 responses and gains of V̇o2, V̇co2, and V̇e are associated with ventilatory, cardiovascular, and/or physical impairments. Kinetic features were examined for 265 COPD patients [forced expiratory volume in 1 s (FEV1): 54 ± 19%predicted] who performed a constant work rate test (duration > 180 s) with breath-by-breath measurements of V̇o2, V̇co2, and V̇e. Negative/positive predictive values were used to define cutoff values of relevant clinical variables below/above which kinetic analyses are (un)likely to be reliable. Kinetic feature values were unreliable for 21% (= 56/265) of the patients and for 79% (= 19/24) of the patients with a peak work rate (WRpeak)< 45 W. Kinetic feature values were considered reliable for 94% (= 133/142) of the patients with an FEV1 > 1.3 L. For patients exhibiting reliable kinetic feature values, V̇o2 MRT was associated with ventilatory (e.g., FEV1 %predicted: P < 0.001; r = −0.35) and physical (e.g., V̇o2peak %predicted: P = 0.009; r = −0.18) impairments. Gains were mainly associated with cardiac function and ventilatory constraints, representing both response efficiency and limitation. Kinetic analyses are likely to be unreliable for patients with a WRpeak < 45 W. Whereas gains enrich analyses of physiological exercise responses, V̇o2 MRT shows potential to serve as a motivation-independent, physiological indicator of physical performance. NEW & NOTEWORTHY A constant work rate test that is standardly performed during a prerehabilitation assessment is unable to provide reliable kinetic feature values for chronic obstructive pulmonary disease (COPD) patients with a peak work rate below 45 W. For patients suffering from less severe impairments, kinetic analyses are a powerful tool to examine physiological exercise responses. Especially oxygen uptake mean response time can serve as a motivation-independent, physiological indicator of physical performance in patients with COPD.

Sensory-mechanical relationships during high-intensity, constant-work-rate exercise in COPD

2006 ◽  
Vol 101 (4) ◽  
pp. 1025-1035 ◽  
Author(s):  
Denis E. O’Donnell ◽  
Alan L. Hamilton ◽  
Katherine A. Webb
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Esophageal Pressure ◽  
Work Rate ◽  
Chronic Obstructive ◽  
Dynamic Hyperinflation ◽  
Obstructive Pulmonary Disease ◽  
Displacement Ratio ◽  
Constant Work Rate ◽  
Anticholinergic Bronchodilator

During constant-work-rate exercise in chronic obstructive pulmonary disease, dyspnea increases steeply once inspiratory reserve volume (IRV) falls to a critical level that prevents further expansion of tidal volume (Vt). We studied the effects of this mechanical restriction on the quality and intensity of exertional dyspnea and examined the impact of an anticholinergic bronchodilator. In a randomized, double-blind, crossover study, 18 patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 s = 40 ± 3%predicted; mean ± SE) inhaled tiotropium 18 μg or placebo once daily for 7–10 days each. Pulmonary function tests and symptom-limited cycle exercise at 75% of each patient’s maximal work capacity were performed 2 h after dosing. Dyspnea intensity (Borg scale), operating lung volumes, breathing pattern, and esophageal pressure ( n = 11) were measured during exercise. Dynamic hyperinflation reached its maximal value early in exercise and was associated with only mild increases in dyspnea intensity and the effort-displacement ratio, which is defined as the ratio between tidal swings of esophageal pressure (expressed relative to maximum inspiratory pressure) and Vt (expressed relative to predicted vital capacity). After a minimal IRV of 0.5 ± 0.1 liter was reached, both dyspnea and the effort-displacement ratio rose steeply until an intolerable level was reached. Tiotropium did not alter dyspnea-IRV relationships, but the increase in resting and exercise inspiratory capacity was associated with an improved effort-displacement ratio throughout exercise. Once a critically low IRV was reached during exercise, dyspnea rose with the disparity between respiratory effort and the Vt response. Changes in dyspnea intensity after tiotropium were positively correlated with changes in this index of neuromechanical coupling.

scholarly journals Responsiveness of Various Exercise-Testing Protocols to Therapeutic Interventions in COPD

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Benoit Borel ◽  
Steeve Provencher ◽  
Didier Saey ◽  
François Maltais
Keyword(s):  
Exercise Testing ◽  
Exercise Tolerance ◽  
Work Rate ◽  
Therapeutic Interventions ◽  
Exercise Intolerance ◽  
Chronic Obstructive ◽  
Exercise Tests ◽  
Obstructive Pulmonary Disease ◽  
Constant Work Rate ◽  
Testing Protocols

Exercise intolerance is a key element in the pathophysiology and course of Chronic Obstructive Pulmonary Disease (COPD). As such, evaluating exercise tolerance has become an important part of the management of COPD. A wide variety of exercise-testing protocols is currently available, each protocol having its own strengths and weaknesses relative to their discriminative, methodological, and evaluative characteristics. This paper aims to review the responsiveness of several exercise-testing protocols used to evaluate the efficacy of pharmacological and nonpharmacological interventions to improve exercise tolerance in COPD. This will be done taking into account the minimally important difference, an important concept in the interpretation of the findings about responsiveness of exercise testing protocols. Among the currently available exercise-testing protocols (incremental, constant work rate, or self-paced), constant work rate exercise tests (cycle endurance test and endurance shuttle walking test) emerge as the most responsive ones for detecting and quantifying changes in exercise capacity after an intervention in COPD.

scholarly journals Box-Jenkins Transfer Function Modelling for Reliable Determination of VO2 Kinetics in Patients with COPD

2019 ◽  
Vol 9 (9) ◽  
pp. 1822 ◽  
Author(s):  
Joren Buekers ◽  
Jan Theunis ◽  
Alberto Peña Fernández ◽  
Emiel F. M. Wouters ◽  
Martijn A. Spruit ◽  
...  
Keyword(s):  
Transfer Function ◽  
Mean Squared Error ◽  
Kinetic Feature ◽  
Reliable Determination ◽  
Exponential Models ◽  
Mean Response Time ◽  
Vo2 Kinetics ◽  
Constant Work Rate ◽  
Function Modelling ◽  
Feature Values

Oxygen uptake (VO2) kinetics provide information about the ability to respond to the increased physical load during a constant work rate test (CWRT). Box-Jenkins transfer function (BJ-TF) models can extract kinetic features from the phase II VO2 response during a CWRT, without being affected by unwanted noise contributions (e.g., phase I contribution or measurement noise). CWRT data of 18 COPD patients were used to compare model fits and kinetic feature values between BJ-TF models and three typically applied exponential modelling methods. Autocorrelation tests and normalised root-mean-squared error values (BJ-TF: 2.8 ± 1.3%; exponential methods A, B and C: 10.5 ± 5.8%, 11.3 ± 5.2% and 12.1 ± 7.0%; p < 0.05) showed that BJ-TF models, in contrast to exponential models, could account for the most important noise contributions. This led to more reliable kinetic feature values compared to methods A and B (e.g., mean response time (MRT), BJ-TF: 74 ± 20 s; methods A-B: 100 ± 56 s–88 ± 52 s; p < 0.05). Only exponential modelling method C provided kinetic feature values comparable to BJ-TF features values (e.g., MRT: 75 ± 20 s). Based on theoretical considerations, we recommend using BJ-TF models, rather than exponential models, for reliable determinations of VO2 kinetics.

scholarly journals Exertional dyspnoea and cortical oxygenation in patients with COPD

2015 ◽  
Vol 46 (6) ◽  
pp. 1615-1624 ◽  
Author(s):  
Yuji Higashimoto ◽  
Noritsugu Honda ◽  
Toshiyuki Yamagata ◽  
Akiko Sano ◽  
Osamu Nishiyama ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Near Infrared ◽  
Cortical Activation ◽  
Chronic Obstructive ◽  
Exertional Dyspnoea ◽  
Oxygen Supplementation ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Constant Work Rate ◽  
Cortical Oxygenation

This study was designed to investigate the association of perceived dyspnoea intensity with cortical oxygenation and cortical activation during exercise in patients with chronic obstructive pulmonary disease (COPD) and exertional hypoxaemia.Low-intensity exercise was performed at a constant work rate by patients with COPD and exertional hypoxaemia (n=11) or no hypoxaemia (n=16), and in control participants (n=11). Cortical oxyhaemoglobin (oxy-Hb) and deoxyhaemoglobin (deoxy-Hb) concentrations were measured by multichannel near-infrared spectroscopy. Increased deoxy-Hb is assumed to reflect impaired oxygenation, whereas decreased deoxy-Hb signifies cortical activation.Exercise decreased cortical deoxy-Hb in control and nonhypoxaemic patients. Deoxy-Hb was increased in hypoxaemic patients and oxygen supplementation improved cortical oxygenation. Decreased deoxy-Hb in the pre-motor cortex (PMA) was significantly correlated with exertional dyspnoea in control participants and patients with COPD without hypoxaemia. In contrast, increased cortical deoxy-Hb concentration was correlated with dyspnoea in patients with COPD and hypoxaemia. With the administration of oxygen supplementation, exertional dyspnoea was correlated with decreased deoxy-Hb in the PMA of COPD patients with hypoxaemia.During exercise, cortical oxygenation was impaired in patients with COPD and hypoxaemia compared with control and nonhypoxaemic patients; this difference was ameliorated with oxygen supplementation. Exertional dyspnoea was related to activation of the pre-motor cortex in COPD patients.

scholarly journals Effect of 12 weeks of once-daily tiotropium/olodaterol on exercise endurance during constant work-rate cycling and endurance shuttle walking in chronic obstructive pulmonary disease

2018 ◽  
Vol 12 ◽  
pp. 175346581875509 ◽  
Author(s):  
François Maltais ◽  
Denis O’Donnell ◽  
Juan Bautista Gáldiz Iturri ◽  
Anne-Marie Kirsten ◽  
Dave Singh ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Cycle Ergometry ◽  
Work Rate ◽  
Chronic Obstructive ◽  
Double Blind ◽  
Endurance Time ◽  
Obstructive Pulmonary Disease ◽  
Once Daily ◽  
Constant Work Rate

Background: The TORRACTO® study evaluated the effects of tiotropium/olodaterol versus placebo on endurance time during constant work-rate cycling and constant speed shuttle walking in patients with chronic obstructive pulmonary disease (COPD) after 12 weeks of treatment. Methods: The effects of once-daily tiotropium/olodaterol (2.5/5 and 5/5 μg) on endurance time during constant work-rate cycle ergometry (CWRCE) after 6 and 12 weeks of treatment were compared with placebo in patients with COPD in a randomized, double-blind, placebo-controlled, parallel-group clinical trial. Endurance time during the endurance shuttle walk test (ESWT) after 6 and 12 weeks of treatment was also evaluated in a subset of patients. Results: A total of 404 patients received treatment, with 165 participating in the ESWT substudy. A statistically significant improvement in endurance time during CWRCE was observed after 12 weeks (primary endpoint) with tiotropium/olodaterol 5/5 µg [14% ( p = 0.02)] but not with tiotropium/olodaterol 2.5/5 µg [9% ( p = 0.14)] versus placebo. In the ESWT substudy, a trend to improvement in endurance time during ESWT after 12 weeks (key secondary endpoint) was observed with tiotropium/olodaterol 5/5 µg [21% ( p = 0.055)] and tiotropium/olodaterol 2.5/5 µg [21% ( p = 0.056)] versus placebo. Conclusion: Tiotropium/olodaterol 5/5 µg improved endurance time during cycle ergometry versus placebo, with a strong tendency to also improve walking endurance time. [ ClinicalTrials.gov identifier: NCT01525615.]

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