Detecting improvements in dyspnea in COPD using a three-minute constant rate shuttle walking protocol

Fixed-intensity exercise tests to measure exertional dyspnoea in chronic heart and lung populations: a systematic review

INTRODUCTION

Exertional dyspnoea is the primary diagnostic symptom for chronic cardiopulmonary disease populations. Whilst a number of exercise tests are used, there remains no gold standard clinical measure of exertional dyspnoea. The aim of this review was to comprehensively describe and evaluate all types of fixed-intensity exercise tests used to assess exertional dyspnoea in chronic cardiopulmonary populations and, where possible, report the reliability and responsiveness of the tests.

METHODS

A systematic search of five electronic databases identified papers that examined 1) fixed-intensity exercise tests and measured exertional dyspnoea, 2) chronic cardiopulmonary populations, 3) exertional dyspnoea reported at isotime or upon completion of fixed-duration exercise tests, and 4) published in English.

RESULTS

Searches identified 8785 papers. 123 papers were included, covering exercise tests using a variety of fixed-intensity protocols. Three modes were identified, as follows: 1) cycling (n=87), 2) walking (n=31) and 3) other (step test (n=8) and arm exercise (n=2)). Most studies (98%) were performed on chronic respiratory disease patients. Nearly all studies (88%) used an incremental exercise test. 34% of studies used a fixed duration for the exercise test, with the remaining 66% using an exhaustion protocol recording exertional dyspnoea at isotime. Exertional dyspnoea was measured using the Borg scale (89%). 7% of studies reported reliability. Most studies (72%) examined the change in exertional dyspnoea in response to different interventions.

CONCLUSION

Considerable methodological variety of fixed-intensity exercise tests exists to assess exertional dyspnoea and most test protocols require incremental exercise tests. There does not appear to be a simple, universal test for measuring exertional dyspnoea in the clinical setting.

Tests to uncover and assess breathlessness: a proposed framework

PURPOSE OF REVIEW

Breathlessness is a common, distressing, and limiting symptom that many people avoid by reducing their activity. This review discusses exertional tests that can be used for uncovering and assessing breathlessness depending on the person's severity of illness, function, the setting, and aim of the assessment.

RECENT FINDINGS

Standardized exertional tests are useful to uncover 'hidden' breathlessness earlier in people who may have adapted their physical activity to limit their breathing discomfort. In 'more fit' ambulatory people and outpatients, cardiopulmonary exercise testing is the gold standard for assessing symptom severity, underlying conditions, and mechanisms and treatment effects. Among field tests, the 6-min walk test is not useful for assessing breathlessness. Instead, the 3-min step test and walk test are validated for measuring breathlessness change in chronic obstructive pulmonary disease. In people with more severe illness (who are most often not breathless at rest), reported tests include upper limb exercise or counting numbers aloud, but a valid and useful test for this population is lacking.

SUMMARY

A framework for selecting the most appropriate test to assess breathlessness validly is proposed, and research needs are identified.

Examining the repeatability of a novel test to measure exertional dyspnoea in chronic obstructive pulmonary disease

BACKGROUND

Exertional dyspnoea(ED) is a hallmark of chronic obstructive pulmonary disease(COPD). We examined the repeatability and face validity of the end-exercise ED(ED_end) response during the Dyspnoea Challenge and compared those to the six-minute walk test (6MWT) in COPD.

METHODS

Twenty-six individuals with COPD(13 Females, age:69 ± 5.5yrs, FEV₁:63.4 ± 11.9 %) completed 2 × 6MWTs and 4 x Dyspnoea Challenges on three occasions. The challenge consisted of a two-minute treadmill walk at 80 % of 6MWT speed(3.9 ± 0.5 km·hr^-1) at either a low(LI_DC:5.3 ± 2%) or high angle of incline(HI_DC:9.5 ± 3%). Dyspnoea(0-10 scale), heart rate(HR) and oxygen saturation(S_pO₂) were monitored continuously.

RESULTS

Mean 6MWT distance was 488 ± 58 m. End-exercise ED and HR were higher in the HI_DC(ED_end 6.2 ± 2.0; HR: 123 ± 17beats·min^-1) compared to the LI_DC(ED_end 4.2 ± 2.0; HR: 119 ± 15beats·min^-1) and the 6MWT(ED_end 4.3 ± 2.0; HR: 115 ± 16beats·min^-1)(P < 0.01). SpO₂ was not different between 6MWT, LI_DC or HI_DC(P = 0.34). The intraclass correlation coefficient(ICC) for each intensity was excellent (HI_DC, ICC = 0.88, LI_DC, ICC = 0.93, P < 0.001) with neither reporting bias(HI_DC, P = 0.63; LI_DC, P = 0.94).

CONCLUSIONS

The Dyspnoea Challenge is a simple measure of ED that appears to have both repeatability and face validity. With further optimisation, this test may enhance the field-based clinical assessment of ED.

Determination of the minimal important difference for Dyspnoea-12 questionnaire in patients with COPD, after pulmonary rehabilitation

INTRODUCTION

The authors of the international task force about the management of Dyspnoea recommend assessing sensory and affective components of dyspnoea. The Dyspnoea-12 questionnaire (D-12) allows to assess both components of dyspnoea. D-12 is valid and reliable but its sensitivity to pulmonary rehabilitation was not studied. The aim of this study was to estimate the minimal important difference (MID) for D-12 in COPD patients undergoing a pulmonary rehabilitation programme (PRP).

METHODS

Severe or very severe COPD patients undergoing a PRP were included. Dyspnoea was assessed using D-12, MMRC dyspnoea scale, London chest of Activity of Daily Living questionnaire (LCADL). Quality of life was assessed using Saint-George respiratory questionnaire (SGRQ) and COPD assessment Test (CAT); exercise capacity using 6-Minute walk Test (6MWT) and 1-minute sit to-stand test (1STST). The MID was evaluated using distribution and anchor-based methods.

RESULTS

Sixty patients (age: 64.4 ± 8.2; FEV1 (%): 28.6 ± 8.1) were included. At the end of the PRP, patients had significantly decreased their dyspnoea measured with D-12, MMRC, LCADL (D-12:23.9 ± 8.9 to 17.6 ± 9.4; MMRC: 3 ± 0.7 to 2.2 ± 1.1, LCADL: 38 ± 13.9 to 31.6 ± 11; p < 0.0001). Using the distribution-based analysis, MID of -2.67 (standard error of measurement) or -4.45 (standard deviation) was found. According to methodology, we could only use SGRQ as anchor. With SGRQ as anchor, the receiver operating characteristic curve identified MID for the change in D-12 at -6.1 (sensibility: 58%, specificity: 79%). The correlation with SGRQ was modest (r = 0.33), so the calculated MID should be interpreted with caution.

CONCLUSION

D-12 is a good tool to assess the decrease of dyspnoea after PR. We propose MID of -6 points. However, Future estimates of MID for the D-12 should use anchors that are more strongly correlated with it.

Effects of Tiotropium/Olodaterol on Activity-Related Breathlessness, Exercise Endurance and Physical Activity in Patients with COPD: Narrative Review with Meta-/Pooled Analyses

Abstract

One of the most debilitating symptoms of chronic obstructive pulmonary disease (COPD) is breathlessness, which leads to avoidance of physical activities in daily living and hastens clinical deterioration. Treatment of patients with COPD with inhaled long-acting muscarinic antagonist (LAMA)/long-acting β₂-agonist (LABA) combination therapy improves airflow limitation, reduces breathlessness compared with LAMA or LABA monotherapies, and improves health status and quality of life. A large clinical trial programme focusing on the effects of tiotropium/olodaterol combination therapy demonstrated that this LAMA/LABA combination improves lung function and reduces hyperinflation (assessed by serial inspiratory capacity measurements) compared with either tiotropium alone or placebo in patients with COPD. Tiotropium/olodaterol also increases exercise endurance capacity and improves patient perception of the intensity of breathlessness compared with placebo. In this narrative review, we focus on the relationship between improving symptoms during activity, the ability to remain active in daily life and how this may impact quality of life. We consider the benefits of therapy optimisation by means of dual bronchodilation with tiotropium/olodaterol, and present new data from meta-analyses/pooled analyses showing that tiotropium/olodaterol improves inspiratory capacity compared with placebo and tiotropium and improves exercise endurance time compared with placebo after 6 weeks of treatment. We also discuss the importance of taking a holistic approach to improving physical activity, including pulmonary rehabilitation and exercise programmes in parallel with bronchodilator therapy and psychological programmes to support behaviour change.

Graphic Abstract

Standardized measurement of breathlessness during exercise

PURPOSE OF REVIEW

Exertional breathlessness is common and pervasive across various chronic disease populations. To accurately assess response to intervention and optimize clinical (symptom) management, detailed assessment of exertional breathlessness is imperative. This review provides an update on current approaches to assess exertional breathlessness and presents the need for individualized assessment of breathlessness standardized for the level of exertion.

RECENT FINDINGS

Breathlessness assessment tools commonly invite people to recall their breathlessness while at rest with reference to activities of daily living. To directly quantify breathlessness, however, requires assessment of the dimensions of breathlessness (e.g., sensory intensity, quality, and unpleasantness) in response to a standardized exercise stimulus. Different exercise stimuli (e.g., self-paced, incremental, and constant work rate exercise tests) have been used to elicit a breathlessness response. Self-paced (e.g., 6-min walk test) and incremental exercise tests assess exercise tolerance or endurance, and are not recommended for assessment of exertional breathlessness. Constant work rate tests, however, including recently validated 3-min constant-rate stair stepping and walking tests, standardize the exercise stimulus to enable the breathlessness response to be directly quantified and monitored over time.

SUMMARY

To adequately guide symptom management and assess intervention efficacy, clinicians and researchers should assess breathlessness with multidimensional assessment tools in response to a standardized and individualized exercise stimulus.

Why treatment efficacy on breathlessness in laboratory but not daily life trials? The importance of standardized exertion

PURPOSE OF REVIEW

Treatments for chronic breathlessness, including opioids and oxygen, have shown efficacy in the controlled laboratory setting, whereas effects have been inconsistent or absent in trials in daily life. This review discusses the lack of standardized exertion as a potential cause of false negative findings for breathlessness in daily life.

RECENT FINDINGS

The level of breathlessness can be modified by patients by changing their level of physical activity. Effects of opioids and oxygen have been shown at standardized level of exertion (iso-time) but not at the end of symptom-limited (peak) exertion. Trials in daily life reporting no effects on breathlessness did not standardize the exertion or employed insensitive methods, such as the 6-min walk test that should not be used for measuring breathlessness. Novel tests - the 3-min walk and stepping tests have been validated in chronic obstructive pulmonary disease and are responsive for measuring change in breathlessness.

SUMMARY

Breathlessness should be measured at standardized exertion, otherwise treatment effects may be biased or overlooked. Tests for valid measurement of breathlessness in clinical practice and daily life are available and emerging.

Relieving exertional dyspnea during the 3-min constant speed shuttle test in patients with COPD with indacaterol/glycopyrronium versus tiotropium: the RED trial

Background:

Exertional dyspnea is a cardinal feature of chronic obstructive pulmonary disease (COPD) and a major cause of activity limitation. Although dual bronchodilation is more effective than bronchodilator monotherapy at improving resting pulmonary function, it is unclear to which extent this translates into superior relief of exertional dyspnea.

Methods:

We conducted a randomized controlled, double-blind, cross-over trial comparing indacaterol 110 µg/glycopyrronium 50 µg once daily (OD) with tiotropium 50 µg OD in patients with moderate to severe COPD and resting hyperinflation (functional residual capacity >120% of predicted value). The primary outcome was Borg dyspnea score at the end of a 3-min constant speed shuttle test after 3 weeks of treatment. Secondary outcomes included changes in Borg dyspnea score after the first dose of study medication, expiratory flows and lung volumes. Statistical analysis was conducted using a cross-over analysis of variance model with repeated measurements.

Results:

A total of 50 patients with COPD and a mean forced expiratory volume in 1 s of 54 ± 11% (mean ± SEM) predicted participated in the cross-over phase of the trial. Compared with baseline, there was a decrease in dyspnea after the first dose of medication with indacaterol/glycopyrronium [mean −1.00, 95% confidence interval (CI) −1.49 to −0.52] but not with tiotropium alone (mean −0.36, 95% CI −0.81 to 0.08). The reduction in dyspnea after the first dose was statistically significant between the two treatments (mean difference of −0.64, 95% CI −1.11 to −0.17). Despite indacaterol/glycopyrronium providing further bronchodilation and lung deflation throughout the trial, the reduction in dyspnea was not sustained at 3 weeks of treatment (mean between-treatment difference at 3 weeks of 0.09, 95% CI −0.44 to 0.61).

Conclusion:

In comparison with bronchodilator monotherapy, indacaterol/glycopyrronium provided greater immediate exertional dyspnea relief, although this difference was not sustained after 3 weeks of therapy despite evidence of further bronchodilation and lung deflation.

The reviews of this paper are available via the supplemental material section.

Predicting the rate of oxygen consumption during the 3-minute constant-rate stair stepping and shuttle tests in people with chronic obstructive pulmonary disease

Background

The 3-minute constant-rate stair stepping (3-min CRSST) and constant-speed shuttle tests (3-min CSST) were developed to assess breathlessness in response to a standardized exercise stimulus. Estimating the rate of oxygen consumption (V’O₂) during these tests would assist clinicians to relate the stepping/shuttle speeds that elicit breathlessness to daily physical activities with a similar metabolic demand. This study: (I) developed equations to estimate the V’O₂ of these tests in people with chronic obstructive pulmonary disease (COPD); and (II) compared the newly developed and American College of Sports Medicine (ACSM) metabolic equations for estimating the V’O₂ of these tests.

Methods

This study was a retrospective analysis of people with COPD who completed a 3-min CRSST (n=98) or 3-min CSST (n=69). Multivariate linear regression estimated predictors (alpha <0.05) of V’O₂ to construct COPD-specific metabolic equations. The mean squared error (MSE) of the COPD-specific and ACSM equations was calculated and compared. Bland-Altman analyses evaluated level of agreement between measured and predicted V’O₂ using each equation; limits of agreement (LoA) and patterns of bias were compared.

Results

Stepping rate/shuttle speed and body mass were identified as significant predictors of V’O₂. The MSE of the COPD-specific equations was 0.05 L·min⁻¹ for both tests. Mean difference between measured and predicted V’O₂ was 0.00 L·min⁻¹ (95% LoA −0.46, 0.46) and 0.00 L·min⁻¹ (95% LoA −0.44, 0.44) for the 3-min CRSST and 3-min CSST, respectively. For the ACSM metabolic equations, the MSE was 0.10 L·min⁻¹ and 0.18 L·min⁻¹ for the 3-min CRSST and 3-min CSST, respectively. The ACSM metabolic equations underestimated V’O₂ of the 3-min CRSST by −0.18 L·min⁻¹ (95% LoA −0.68, 0.32), and overestimated V’O₂ of the 3-min CSST by 0.35 L·min⁻¹ (95% LoA −0.14, 0.84).

Conclusions

This study presents metabolic equations to predict V’O2 of the 3-min CRSST and 3-min CSST for people with COPD that are more accurate than the ACSM metabolic equations.

Dual bronchodilation with tiotropium/olodaterol further reduces activity-related breathlessness versus tiotropium alone in COPD

The 3-min constant speed shuttle test (CSST) was used to examine the effect of tiotropium/olodaterol compared with tiotropium at reducing activity-related breathlessness in patients with chronic obstructive pulmonary disease (COPD).This was a randomised, double-blind, two-period crossover study including COPD patients with moderate to severe pulmonary impairment, lung hyperinflation at rest and a Mahler Baseline Dyspnoea Index <8. Patients received 6 weeks of tiotropium/olodaterol 5/5 µg and tiotropium 5 µg in a randomised order with a 3-week washout period. The speed for the 3-min CSST was determined for each patient such that an intensity of breathing discomfort ≥4 ("somewhat severe") on the modified Borg scale was reached at the end of a completed 3-min CSST.After 6 weeks, there was a decrease in the intensity of breathlessness (Borg dyspnoea score) at the end of the 3-min CSST from baseline with both tiotropium (mean -0.968, 95% CI -1.238- -0.698; n=100) and tiotropium/olodaterol (mean -1.325, 95% CI -1.594- -1.056; n=101). The decrease in breathlessness was statistically significantly greater with tiotropium/olodaterol versus tiotropium (treatment difference -0.357, 95% CI -0.661- -0.053; p=0.0217).Tiotropium/olodaterol reduced activity-related breathlessness more than tiotropium in dyspnoeic patients with moderate to severe COPD exhibiting lung hyperinflation.

Measurement Properties of Short Lower Extremity Functional Exercise Tests in People With Chronic Obstructive Pulmonary Disease: Systematic Review

BACKGROUND

An increasing variety of short functional exercise tests are reported in people with chronic obstructive pulmonary disease (COPD). Systematic review of the psychometric properties of these exercise tests is indicated.

PURPOSE

The aim of this study was to determine the reliability, validity, and responsiveness of short (duration < 6 min) lower extremity functional exercise tests in people with COPD.

DATA SOURCES

Five databases were searched: MEDLINE, Embase, Scopus, AMED, and CINAHL.

STUDY SELECTION

Studies reporting psychometric properties of short functional exercise tests in people with COPD were included.

DATA EXTRACTION

Two reviewers independently extracted data and rated the quality of each measurement property using the COnsensus-based Standards for the Selection of Health Measurement INstrument (COSMIN).

DATA SYNTHESIS

Twenty-nine studies were identified reporting properties of 11 different tests. Four-meter gait speed [4MGS] and 5 repetition sit-to-stand [5STS] demonstrated high reliability (ICC = .95-.99; .97) with no learning effect (COSMIN study ratings = good--excellent). Their validity for use as a stratification tool anchored against an established prognostic indicator (area under receiver operator characteristics curve [AUC] = 0.72-0.87; 0.82) and responsiveness to change after pulmonary rehabilitation was greatest in more frail people with COPD. Studies of the Timed "Up and Go" [TUG] test support use of a practice test and show discriminative ability to detect falls history and low six-minute walk distance (AUC = 0.77; 0.82, COSMIN ratings = fair-excellent).

LIMITATIONS

Earlier studies were limited by small sample size. Limited data of lower study quality was identified for step tests and the Two-Minute Walk Test.

CONCLUSIONS

Selected short functional exercise tests can complement established exercise capacity measures, in stratification and measuring responsiveness to change especially in people with COPD and lower functional ability.

Three-minute constant rate step test for detecting exertional dyspnea relief after bronchodilation in COPD

Background

The aim of this study was to evaluate the responsiveness of the 3-minute constant rate step test (3-MST) to detect the relief of exertional dyspnea (respiratory discomfort) after acute bronchodilation in COPD patients.

Patients and methods

A total of 40 patients with moderate-to-severe COPD (mean forced expiratory volume in 1 second: 45.7 (±14.7), % predicted) performed four 3-MSTs at randomly assigned stepping rates of 14, 16, 20 and 24 steps/min after inhalation of nebulized ipratropium bromide (500 µg)/salbutamol (2.5 mg) and saline placebo, which were randomized to order. Patients rated their intensity of perceived dyspnea at the end of each 3-MST using Borg 0–10 category ratio scale.

Results

A total of 37 (92.5%), 36 (90%), 34 (85%) and 27 (67.5%) patients completed all 3 minutes of exercise at 14, 16, 20 and 24 steps/min under both treatment conditions, respectively. Compared with placebo, ipratropium bromide/salbutamol significantly decreased dyspnea at the end of the third minute of exercise at 14 steps/min (by 0.6±1.0 Borg 0–10 scale units, P<0.01) and 16 steps/min (by 0.7±1.3 Borg 0–10 scale units, P<0.01); however, no statically significant differences were observed between treatments at 20 and 24 steps/min (both P>0.05).

Conclusion

The 3-MST, when performed at 14 and 16 steps/min, was responsive to detect the relief of exertional dyspnea after acute bronchodilation in patients with moderate-to-severe COPD.

Factors associating with shuttle walking test results in community-dwelling elderly people

BACKGROUND

The shuttle walking test (SWT) is a simple, widely used method for assessing endurance performance in the elderly. Despite widespread community use, its associated factors are unclear.

AIMS

We aim to identify previously undefined SWT association factors in community-dwelling elderly people.

METHODS

Herein, 149 healthy elderly Japanese subjects performed the SWT, and were assessed for height, weight, smoking history, 10-m walk time, Timed Up and Go (TUG) scores, handgrip strength, skeletal mass index (SMI), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), cardio-ankle vascular index, and ankle brachial index. We divided men and women into higher and lower SWT score groups, compared between-group parameters, and performed stepwise multivariate logistic regression analysis to identify factors independently associated with SWT scores.

RESULTS

Age, BMI, 10-m walk time, TUG score, SMI, FVC (L; %-predicted), and FEV1 (L; %-predicted) were significantly different between SWT score groups for men, while in women, significant differences were observed in age, TUG score, handgrip strength, FVC (L; %-predicted), and FEV1 (L; %-predicted) (p < 0.05). In the multivariate logistic regression model, 10-m walk time, and FEV1 showed significant associations with SWT results in men; among women, age was the only significantly associated factor (p < 0.05).

CONCLUSIONS

Results indicate that better lung function and shorter walk time independently associate with SWT results in community-dwelling men; in women, age is the only association. Our findings may offer insight when considering the focus of community exercise programs among the elderly.

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

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.