Qualitative dimensions of exertional dyspnea in fibrotic interstitial lung disease

Translating the Interplay of Cognition and Physical Performance in COPD and Interstitial Lung Disease: Meeting Report and Literature Review

TOPIC IMPORTANCE

Cognitive and physical limitations are common in individuals with chronic lung diseases, but their interactions with physical function and activities of daily living are not well characterized. Understanding these interactions and potential contributors may provide insights on disability and enable more tailored rehabilitation strategies.

REVIEW FINDINGS

This review summarizes a 2-day meeting of patient partners, clinicians, researchers, and lung associations to discuss the interplay between cognitive and physical function in people with chronic lung diseases. This report covers four areas: (1) cognitive-physical limitations in patients with chronic lung diseases; (2) cognitive assessments; (3) strategies to optimize cognition and motor control; and (4) future research directions. Cognitive and physical impairments have multiple effects on quality of life and daily function. Meeting participants acknowledged the need for a standardized cognitive assessment to complement physical assessments in patients with chronic lung diseases. Dyspnea, fatigue, and age were recognized as important contributors to cognition that can affect motor control and daily physical function. Pulmonary rehabilitation was highlighted as a multidisciplinary strategy that may improve respiratory and limb motor control through neuroplasticity and has the potential to improve physical function and quality of life.

SUMMARY

There was consensus that cognitive function and the cognitive interference of dyspnea in people with chronic lung diseases contribute to motor control impairments that can negatively affect daily function, which may be improved with pulmonary rehabilitation. The meeting generated several key research questions related to cognitive-physical interactions in individuals with chronic lung diseases.

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.

Dyspnea: Common Side Effect

For dyspnea, standards of care are based on emerging evidence-based practice. Dyspnea, or shortness of breath, is a subjective experience of breathing discomfort marked by distinct sensations of varying intensity. Resulting from interactions among physiologic, psychological, social, and environmental factors, dyspnea may lead to secondary physiologic and behavioral responses. Dyspnea can be caused by cardiac and pulmonary disease (e.g., congestive heart failure, acute coronary syndrome, pneumonia, chronic obstructive pulmonary disease, pulmonary embolism), as well as other conditions (e.g., anemia, mental disorders, lung cancer).

Multidimensional breathlessness response to exercise: Impact of COPD and healthy ageing

This study compared the multidimensional breathlessness response to incremental cardiopulmonary cycle exercise testing (CPET) in people with chronic obstructive pulmonary disease (COPD; n = 14, aged 69 ± 9 years, forced expiratory volume in 1-sec = 54 ± 16 % predicted) and healthy older (OA) (n = 35, aged 68 ± 5 years) and younger (YA) (n = 19, aged 28 ± 8 years) adults. Participants performed CPET and successively rated overall breathlessness intensity, unsatisfied inspiration, breathing too shallow, work/effort of breathing, and breathlessness-related unpleasantness, fear, and anxiety using the 0-10 Borg scale. At any given percent predicted peak minute ventilation, people with COPD rated all breathlessness sensations higher than OA and YAs, who were similar. Most between group differences disappeared when examined in relation to inspiratory reserve volume, except people with COPD reported higher levels of unsatisfied inspiration and breathing too shallow (vs YA), and breathlessness-related fear and anxiety (vs OA and YAs). Multidimensional ratings of breathlessness sensations during CPET provides further insight into differences in exertional symptom perceptions among people with COPD and without COPD.

Multidimensional breathlessness assessment during cardiopulmonary exercise testing in healthy adults

PURPOSE

This study explored if healthy adults could discriminate between different breathlessness dimensions when rated immediately one after another (successively) during symptom-limited incremental cardiopulmonary cycle exercise testing (CPET) using multiple single-item rating scales.

METHODS

Fifteen apparently healthy adults (60% male) aged 22 ± 2 years performed six incremental cycle CPETs separated by ≥ 48 h. During each CPET (at rest, every 2-min and at end exercise), participants rated different breathlessness sensations using the 0-10 modified Borg scale using one of six assessment protocols, randomized for order: (1) 'BREATHLESS_ALL' = breathlessness sensory intensity (SI), breathlessness unpleasantness (UN), work/effort of breathing (SQ_W/E), and unsatisfied inspiration (SQ_UI) assessed; (2) SI and UN assessed; and (3-6) SI, UN, SQ_W/E, and SQ_UI each assessed alone. Physiological responses to CPET were also evaluated.

RESULTS

Physiological and breathlessness responses to CPET were comparable across the six protocols, with the exception of SI rated lower at the highest submaximal power output (220 ± 56 watts) during the BREATHLESS_ALL protocol (0-10 Borg units 4.2 ± 1.7) compared to SI + UN (5.2 ± 2.1, p = 0.03) and SI alone (5.1 ± 1.9, p = 0.04) protocols. Ratings of SI and SQ_W/E were not significantly different when assessed in the same protocol, and were significantly higher than UN and SQ_UI, which were comparable.

CONCLUSION

In healthy younger adults, use of two separate single-item rating scales to assess breathlessness during CPET is feasible and enables the distinct sensory intensity and affective dimensions of exertional breathlessness to be assessed.