Fatigue in Chronic Respiratory Diseases: Theoretical Framework and Implications For Real-Life Performance and Rehabilitation

Like walking through treacle: the experience of fatigue for young people with interstitial lung disease

Interstitial Lung Disease in childhood (chILD) is rare, and little research has been conducted into the experience of fatigue. Fatigue is a complex phenomenon that can be difficult to quantify due to the various physiological and psychological factors involved. However, fatigue can significantly impact a range of quality-of-life areas for those with a respiratory condition. Our aim is to understand if there are any clinical or research needs relating to fatigue for young people with chILD. This qualitative, non-clinical study explores the lived experience of fatigue in young people with chILD. Fifteen participants comprising child-parent dyads (n = 2), young adults (n = 4) and parents (n = 9) were recruited from chILD patient organisations and online communities. We focused on the experience of fatigue in terms of how it is communicated, the symptoms, and their impact. We explored whether any factors led to the young person being motivated to push beyond fatigue. Data was analysed by constructivist grounded theory. There were three main themes of interest: (i) the experience of fatigue that includes reporting abnormal weakness and behavioural affect; (ii) the consequences of fatigue, such as its impact on education, society, and quality-of-life; (iii) motivational strategies and supportive measures that help young people manage their fatigue. Fatigue is a complex, multi-dimensional phenomenon for those living with chILD. For future work, we recommend incorporating the discussion of fatigue into clinic settings to assess any quality-of-life burden factors alongside living with chILD.

Challenges of symptom management in interstitial lung disease: dyspnea, cough, and fatigue

INTRODUCTION

Interstitial lung disease (ILD) is a broad group of conditions characterized by fibrosis of the lung parenchyma. Idiopathic pulmonary fibrosis (IPF) is the most common subvariant. IPF is marked by considerable symptom burden of dyspnea, cough and fatigue that is often refractory to optimal disease-directed treatment.

AREAS COVERED

In this narrative review, we searched MEDLINE for articles related to the current evidence regarding management of chronic dyspnea, cough, and fatigue as three of the most prevalent and distressing symptoms associated with IPF and other ILDs. Each symptom shares common features of multi-factorial etiology and a lack of safe and effective pharmacological therapies. Both corticosteroids and opioids have been utilized in this context, yet there is insufficient evidence of therapeutic benefit and considerable risk of harms. Whilst some may benefit from symptom-directed pharmacological management, usage must be carefully monitored. Use of non-pharmacological strategies, such as breathing techniques and speech therapy represent low risk and low-cost option, yet broader validation of these therapies' effectiveness is needed.

EXPERT OPINION

Symptom management in IPF and other ILDs requires an iterative and individualized approach. Leveraging the expertise of multidisciplinary teams within an integrated care setting is an important opportunity to maximize health outcomes.

Muscle endurance, neuromuscular fatigability, and cognitive control during prolonged dual-task in people with chronic obstructive pulmonary disease: a case-control study

PURPOSE

Recent studies suggest that, compared to healthy individuals, people with chronic obstructive pulmonary disease (pwCOPD) present a reduced capacity to perform cognitive-motor dual-task (CMDT). However, these studies were focused on short-duration CMDT offering limited insight to prolonged CMDT inducing fatigue, which can be encountered in daily life. The present study aimed to explore the effect of adding a cognitive task during repeated muscle contractions on muscle endurance, neuromuscular fatigability, and cognitive control in pwCOPD compared to healthy participants.

METHODS

Thirteen pwCOPD and thirteen age- and sex-matched healthy participants performed submaximal isometric contractions of the knee extensors until exhaustion in two experimental sessions: (1) without cognitive task and (2) with a concurrent working memory task (i.e., 1-back task). Neuromuscular fatigability (as well as central and peripheral components measured by peripheral magnetic stimulation), cognitive performance, and perceived muscle fatigue were assessed throughout the fatiguing tasks.

RESULTS

Independently to the experimental condition, pwCOPD exhibited lower muscle endurance compared to healthy participants (p = 0.039), mainly explained by earlier peripheral fatigue and faster attainment of higher perceived muscle fatigue (p < 0.05). However, neither effect of cognitive task (p = 0.223) nor interaction effect (group × condition; p = 0.136) was revealed for muscle endurance. Interestingly, cognitive control was significantly reduced only in pwCOPD at the end of CMDT (p < 0.015), suggesting greater difficulty for patients with dual tasking under fatigue.

CONCLUSION

These findings provide novel insights into how and why fatigue develops in COPD in dual-task context, offering a rationale for including such tasks in rehabilitation programs.

Content Validation of the QOL-B-RD and PROMIS-F SF-7a to Measure Respiratory and Fatigue Symptoms of MAC Lung Disease

INTRODUCTION

The Quality of Life-Bronchiectasis (QOL-B) questionnaire and Patient Reported Outcome Measurement Information System Short Form v1.0-Fatigue 7a (PROMIS-F SF-7a) have the potential to measure respiratory and fatigue symptoms, respectively, in patients with Mycobacterium avium complex (MAC) lung disease but have not yet been evaluated for content validity in this population.

METHODS

Semi-structured qualitative interviews were conducted in United States patients with a current MAC lung disease diagnosis. Concept elicitation (CE) interviews were conducted (n = 25 participants) to identify key respiratory and fatigue symptoms expressed as important and relevant to patients with MAC lung disease and to evaluate the appropriateness of the QOL-B and PROMIS-F SF-7a to measure these symptoms. Cognitive interviews (CIs) were subsequently conducted (n = 20 participants) to evaluate the relevance, comprehensibility, and appropriateness of the QOL-B respiratory domain (QOL-B-RD) and PROMIS-F SF-7a. All interviews were recorded, transcribed, and coded for qualitative content analysis.

RESULTS

The most important or relevant respiratory symptom concepts to CE interview participants were "cough," "shortness of breath during activity," and "mucus/phlegm." The most important or relevant fatigue symptom concepts were "tiredness," "lack of energy," and "tire easily/low stamina." These symptoms are covered by existing items in the QOL-B-RD and PROMIS-F SF-7a. Cognitive interview participants' feedback confirmed the item content, response options, concept attributes, and recall period for each instrument were effective, relevant, and meaningful to most patients with MAC lung disease. Based on Wave 1 findings, the QOL-B instructions were revised for the Wave 2 interviews, where the text referencing "bronchiectasis" was replaced with "your lung condition." Participant feedback in Wave 2 confirmed the revised instruction wording was easily understood and appropriate.

CONCLUSIONS

The study results support the content validity of the QOL-B-RD and PROMIS-F SF-7a, which were shown to be relevant and appropriate to evaluate respiratory and fatigue symptoms, respectively, in patients with MAC lung disease.

Age-specific effects of a sustained cognitive activity on perceived cognitive fatigue as well as single- and dual-task treadmill walking performance

During their daily lives humans are often confronted with sustained cognitive activities (SCA) leading to state fatigue, a psychobiological state characterized by a decrease in cognitive and/or motor performance and/or an increase in perception of fatigue. It was recently shown that performing SCA can impair overground dual-task gait performance in older adults, but it is currently unknown whether there is a task- and/or age-specific modulation in gait performance during treadmill walking. Therefore, the effect of a SCA on single- and dual-task treadmill walking performance was investigated in young and old adults. Using a crossover design, spatio-temporal gait parameters of 24 young and 23 older healthy participants were measured using motion capturing during single- and dual-task (including three cognitive interference tasks: word list generation, arithmetic, and Stroop-task) treadmill walking before and after SCA (30 min Stroop-task) and a control task (reading). Moreover, cognitive fatigue, wakefulness, mood, and arousal were assessed. Although the SCA induced age-specific perceptual responses, no difference was found for cognitive performance during the Stroop-task. The cognitive interference task performance (word list generation, arithmetic, and Stroop-task) during walking on the treadmill did not decrease after the SCA. Single- and dual-task gait performance (e. g., step width and step length) specifically changed after the SCA and after the reading control task in both groups. Data indicate that perceived cognitive fatigue has an impact on single- and dual-task treadmill walking performance, with task- and age-specific differences. Although no general age-specific changes in single- and dual task gait performance following SCA were identified, perceived cognitive fatigue should be considered as an intrinsic risk factor for falls.

Cross-cultural translation, validation, and responsiveness of the Pittsburgh Fatigability Scale - Italian version (PFS-I) in a mixed-sample of older adults

INTRODUCTION

Older adults experience fatigue which impacts health-related quality of life. The Pittsburgh Fatigability Scale (PFS) was specifically designed to assess perceived physical and mental fatigability in older adults. The aim of this study was to translate the PFS into Italian (PFS-I) and to investigate its psychometric properties.

METHODS

The PFS-I was translated in accordance with international standards. The following properties were evaluated: structural validity, internal consistency, hypotheses testing for construct validity, test-retest reliability using intraclass correlation coefficients (ICC), and minimal clinically important difference (MCID) for responsiveness.

RESULTS

The study included 87 older adults with cardiovascular/respiratory diseases (CVRD), 46 with Parkinson disease (PD), and 67 healthy controls (HC). The PFS-I Physical and Mental subscales scores were significantly different in these populations, with HC reporting the lowest fatigability. Exploratory and confirmatory factor analysis showed a two-factor structure for both subscales, with good internal consistency (Cronbach's alpha: 0.86 and 0.89, respectively). The PFS-I Physical subscale showed weak goodness-of-fit of the confirmatory factor analysis models, whereas the PFS-I Mental subscale was deemed acceptable. Construct validity of the PFS-I was excellent with 75% (18 out of 24) of hypotheses accepted. Test-retest reliability was analyzed in a subset of 23 patients with CVRD and showed excellent results for both the PFS-I Physical and Mental subscales (ICC = 0.93 and 0.92, respectively). MCID ranged between 6 and 7 points for the Physical and 7-9 points for the Mental subscale.

CONCLUSIONS

The PFS-I is a valid, reliable, and responsive instrument to assess perceived fatigability for healthy older adults as well as those with CRVD and PD.

The 1-min sit-to-stand test induces a significant and reliable level of neuromuscular fatigability: insights from a mobile app analysis

PURPOSE

The performance metric associated with the execution of the 1-min sit-to-stand (1STS) typically relies on the number repetitions completed in 1 min. This parameter presents certain limitations (e.g., ceiling effect, motivational factors) which can impede its interpretation. Introducing additional parameters, such as neuromuscular fatigability level, could enhance the informative value of the 1STS and facilitate its interpretation. This study aimed to assess (i) whether the 1STS induces fatigability and (ii) the reliability of the fatigability level.

METHODS

Forty young, healthy, and active participants underwent the 1STS twice during the same session. Isolated sit-to-stand maneuvers were performed before, immediately, and 1 min after completing the 1STS. A mobile app was utilized to obtain time (STST), velocity (STSV), and muscle power (STSP) from these sit-to-stand maneuvers. The pre-post change in these parameters served as the fatigability marker. Reliability was assessed using the intra-class correlation coefficient (ICC) and the coefficient of variation (CV).

RESULTS

The mean number of repetitions during the 1STS was 63 ± 9. Significant decline in performance was observed for STST (13 ± 8%), STSV (-11.2 ± 6%), and STSP (-5.2 ± 3%), with more than 74% of participants exhibiting a decline beyond the minimal detectable change. Excellent between-session reliability (ICC ≥ 0.9; CV ≤ 5.3) was observed for the mobile app variables.

CONCLUSION

The 1STS induces significant levels of fatigability. The fatigability indicators derived from the mobile app demonstrated remarkable reliability. Utilizing this user-friendly interface for computing fatigability may empower professionals to acquire insightful complementary indicators from the 1STS.

Changes in fatigue symptoms following an exercise-based rehabilitation programme for patients with long COVID

Background

There is evidence to support COVID-19 rehabilitation programmes improving persistent COVID-19 symptoms; however, there is concern that therapies that include an exercise component may increase fatigue and post-exertional symptom exacerbation (PESE). The objectives of the present study were to determine the effect of a 6-week COVID-19 rehabilitation programme on fatigue and PESE in individuals with ongoing COVID-19 symptoms.

Methods

After a routine medical assessment, individuals with persistent COVID-19 symptoms were enrolled on a 6-week COVID-19 specific rehabilitation programme. The programme included symptom-titrated exercise, education and self-management advice. Fatigue was assessed pre- and post-programme using the Functional Assessment Chronic Illness Therapy Fatigue questionnaire (FACIT). Exercise capacity (Incremental and Endurance Shuttle Walking Test (ISWT and ESWT)) and PESE (DePaul Symptom Questionnaire (DSQ)) were also assessed pre- and post-programme. Composite scores were calculated for the frequency and severity domains of the DSQ.

Results

148 patients (median (IQR) age 59 (49-72) years, 82 (55%) female, 81 (54%) hospitalised) completed the COVID-19 rehabilitation programme. FACIT score was reduced pre- to post-programme by a mean (CI) change of -5 (-7- -4); p<0.01. Exercise capacity increased by 82 (65-99) m for the ISWT and 398 (333-462) s for the ESWT (n=148). PESE was assessed in 44 patients. The DSQ frequency and severity composite score improved by 20 (13-28) and 19 (13-26) points, respectively (p<0.01, n=44).

Conclusion

These data demonstrate the potential benefits of a COVID-19 rehabilitation programme in improving fatigue, exercise capacity and symptom exacerbation in those with persistent COVID-19 symptoms.

Beyond the Lungs: O 2 Supplementation Improves Cerebral Oxygenation and Fatigue during Exercise in Interstitial Lung Disease

PURPOSE

Cerebral hypoxia may exacerbate the perception of fatigue. We previously demonstrated that exercise-related hypoxemia, a hallmark of fibrotic interstitial lung disease ( f -ILD), dose dependently impairs cerebral oxygenation in these patients. It is unknown whether normalizing cerebral oxygenation with O 2 supplementation would be associated with positive changes in a relevant patient-centered outcome during exercise in f -ILD, such as improved perceived fatigue.

METHODS

Fourteen patients (12 males, 72 ± 8 yr, 8 with idiopathic pulmonary fibrosis, lung diffusing capacity for carbon monoxide = 44% ± 13% predicted) performed a constant-load (60% peak work rate) cycle test to symptom limitation (Tlim) breathing medical air. Fourteen controls cycled up to Tlim of an age- and sex-matched patient. Patients repeated the test on supplemental O 2 (fraction of inspired O 2 = 0.41 ± 0.08) for the same duration. Near-infrared spectroscopy and the rating-of-fatigue (ROF) scale assessed prefrontal cortex oxygenation and perceived fatigue, respectively.

RESULTS

Patients showed severe exertional hypoxemia (Tlim O 2 saturation by pulse oximetry = 80% ± 8%); they had poorer cerebral oxygenation (e.g., oxy-deoxyhemoglobin difference [HbDiff] = -3.5 ± 4.7 [range = -17.6 to +1.9] vs +1.9 ± 1.7 μmol from rest) and greater fatigue (ROF = 6.2 ± 2.0 vs 2.6 ± 2.3) versus controls under air ( P < 0.001). Reversal of exertional hypoxemia with supplemental O 2 led to improved HbDiff (+1.7 ± 2.4 μmol from rest; no longer differing from controls) and lower ROF scores (3.7 ± 1.2, P < 0.001 vs air) in patients. There was a significant correlation between O 2 -induced changes in HbDiff and ROF scores throughout exercise in f -ILD ( rrepeated-measures correlation = -0.51, P < 0.001).

CONCLUSIONS

Supplemental O 2 improved cerebral oxygenation during exercise in f -ILD, which was moderately associated with lower ratings of perceived fatigue. Reversing cerebral hypoxia with O 2 supplementation may thus have positive effects on patients' disablement beyond those expected from lower ventilation and dyspnea in this patient population.

Validity and Reliability of the Fatigue Severity Scale in a Real-World Interstitial Lung Disease Cohort

Rationale: Fatigue is a common and debilitating symptom for people living with interstitial lung disease (ILD). Studies on fatigue in ILD are limited, and little headway has been made toward developing interventions targeting the alleviation of fatigue. A barrier to progress is a lack of knowledge around the performance characteristics of a patient-reported outcome measure to assess fatigue in patients with ILD. Objectives: To assess the validity and reliability of the Fatigue Severity Scale (FSS) for measuring fatigue in a national cohort of patients with ILD. Methods: FSS scores and several anchors were measured in 1,881 patients from the Pulmonary Fibrosis Foundation Patient Registry. Anchors included the Short Form 6D Health Utility Index (SF-6D) score and a single vitality question from the SF-6D; the University of California, San Diego, Shortness of Breath Questionnaire; FVC; DlCO; and 6-minute-walk distance. Internal consistency reliability, concurrent validity, and known-groups validity were assessed. Structural validity was assessed using confirmatory factor analysis. Measurements and Main Results: The FSS demonstrated high internal consistency (Cronbach's α = 0.96). There were moderate to strong correlations between FSS score and patient-reported anchors (vitality question from the SF-6D [r = 0.55] and University of California, San Diego, Shortness of Breath Questionnaire total score [r = 0.70]) and weak correlations between FSS score and physiological measures (FVC [r = -0.24], percentage predicted DlCO [r = -0.23], and 6-minute-walk distance [r = -0.29]). Higher mean FSS scores, indicating greater fatigue, were observed among patients using supplemental oxygen, those prescribed steroids, and those with lower percentage predicted FVC and percentage predicted DlCO. The confirmatory factor analysis results suggest that the nine questions of the FSS reflect one dimension of fatigue. Conclusions: Fatigue is an important patient-centered outcome in ILD that is poorly correlated with physiological measures of disease severity, including lung function and walk distance. These findings further support the need for a reliable and valid measure of patient-reported fatigue in ILD. The FSS possesses acceptable performance characteristics for assessing fatigue and distinguishing different degrees of fatigue among patients with ILD.

Upper-Limb Kinematic Behavior and Performance Fatigability of Elderly Participants Performing an Isometric Task: A Quasi-Experimental Study

Upper-limb position-sustained tasks (ULPSIT) are involved in several activities of daily living and are associated with high metabolic and ventilatory demand and fatigue. In older people, this can be critical to the performance of daily living activities, even in the absence of a disability.

OBJECTIVES

To understand the ULPSIT effects on upper-limb (UL) kinetics and performance fatigability in the elderly.

METHODS

Thirty-one (31) elderly participants (72.61 ± 5.23 years) performed an ULPSIT. The UL average acceleration (AA) and performance fatigability were measured using an inertial measurement unit (IMU) and time-to-task failure (TTF).

RESULTS

The findings showed significant changes in AA in the X- and Z-axes (p < 0.05). AA differences in women started earlier in the baseline cutoff in the X-axis, and in men, started earlier between cutoffs in the Z-axis. TTF was positively related to AA in men until 60% TTF.

CONCLUSIONS

ULPSIT produced changes in AA behavior, indicative of movement of the UL in the sagittal plane. AA behavior is sex related and suggests higher performance fatigability in women. Performance fatigability was positively related to AA only in men, where movement adjustments occurred in an early phase, though with increased activity time.

Fatigue and Human Performance: An Updated Framework

Fatigue has been defined differently in the literature depending on the field of research. The inconsistent use of the term fatigue complicated scientific communication, thereby limiting progress towards a more in-depth understanding of the phenomenon. Therefore, Enoka and Duchateau (Med Sci Sports Exerc 48:2228-38, 2016, [3]) proposed a fatigue framework that distinguishes between trait fatigue (i.e., fatigue experienced by an individual over a longer period of time) and motor or cognitive task-induced state fatigue (i.e., self-reported disabling symptom derived from the two interdependent attributes performance fatigability and perceived fatigability). Thereby, performance fatigability describes a decrease in an objective performance measure, while perceived fatigability refers to the sensations that regulate the integrity of the performer. Although this framework served as a good starting point to unravel the psychophysiology of fatigue, several important aspects were not included and the interdependence of the mechanisms driving performance fatigability and perceived fatigability were not comprehensively discussed. Therefore, the present narrative review aimed to (1) update the fatigue framework suggested by Enoka and Duchateau (Med Sci Sports Exerc 48:2228-38, 2016, [3]) pertaining the taxonomy (i.e., cognitive performance fatigue and perceived cognitive fatigue were added) and important determinants that were not considered previously (e.g., effort perception, affective valence, self-regulation), (2) discuss the mechanisms underlying performance fatigue and perceived fatigue in response to motor and cognitive tasks as well as their interdependence, and (3) provide recommendations for future research on these interactions. We propose to define motor or cognitive task-induced state fatigue as a psychophysiological condition characterized by a decrease in motor or cognitive performance (i.e., motor or cognitive performance fatigue, respectively) and/or an increased perception of fatigue (i.e., perceived motor or cognitive fatigue). These dimensions are interdependent, hinge on different determinants, and depend on body homeostasis (e.g., wakefulness, core temperature) as well as several modulating factors (e.g., age, sex, diseases, characteristics of the motor or cognitive task). Consequently, there is no single factor primarily determining performance fatigue and perceived fatigue in response to motor or cognitive tasks. Instead, the relative weight of each determinant and their interaction are modulated by several factors.

Perceptions of the Fatigue Experience and a Breathing Awareness Meditation-Integrated mHealth App for Fatigue and Stress in Patients with Sarcoidosis

Objective

Sarcoidosis-associated fatigue is a debilitating consequence of sarcoidosis, a multi-system inflammatory disease, and may be related to increased stress associated with sarcoidosis. Breathing awareness meditation has potential as an intervention for managing stress and fatigue for sarcoidosis patients (SPs). This project's aim was to obtain feedback from key informants to design and tailor a patient-centered Sarcoidosis Patient Resource and Companion (SPARC) mHealth App developed for SPs to manage fatigue and stress at home using breathing awareness meditation.

Methods

We used a mixed-method patient/user-centered design with triangulation to understand SPs experiences of sarcoidosis-associated fatigue and stress (n = 13), and obtain feedback on the SPARC App-prototype integrating breathing awareness meditation from these SPs and health care team members (HCTMs; n = 5). Using deductive content analysis, transcribed interviews were coded for themes and subthemes.

Results

We report on findings from qualitative interviews and assessment of SPs' experiences including themes describing fatigue/stress interactions. Themes indicated that SPs find fatigue to be a profoundly difficult experience affecting multiple domains of functioning for which they perceive few effective strategies to cope. SPs and HCTMs shared feedback on the SPARC App-prototype after a test session; it was reported to be user friendly and to have potential for improving fatigue/stress, and key points for tailoring the App to SPs were shared.

Conclusion

Sarcoidosis-associated fatigue poses a significant burden for SPs. The SPARC App-prototype with breathing awareness meditation was acceptable and feasible to use and was well-received by SPs and HCTMs. Future iterations of the SPARC App to test the effect of breathing awareness meditation on fatigue will need to incorporate recommendations for tailoring for SPs.

Differences in time to task failure and fatigability between children and young adults: A systematic review and meta-analysis

The transition from childhood to adulthood is characterized by many physiological processes impacting exercise performance. Performance fatigability and time to task failure are commonly used to capture exercise performance. This review aimed to determine the differences in fatigability and TTF between youth (including both children and adolescents) and young adults, and to evaluate the influence of exercise modalities (i.e., exercise duration and type of exercise) on these differences. Medline, SPORTDiscus and Cochrane Library were searched. Thirty-four studies were included. The meta-analyses revealed that both children (SMD −1.15; p &lt; 0.001) and adolescents (SMD −1.26; p = 0.022) were less fatigable than adults. Additional analysis revealed that children were less fatigable during dynamic exercises (SMD −1.58; p &lt; 0.001) with no differences during isometric ones (SMD –0.46; p = 0.22). Children (SMD 0.89; p = 0.018) but not adolescents (SMD 0.75; p = 0.090) had longer TTF than adults. Additional analyses revealed 1) that children had longer TTF for isometric (SMD 1.25; p &lt; 0.001) but not dynamic exercises (SMD −0.27; p = 0.83), and 2) that TTF differences between children and adults were larger for short- (SMD 1.46; p = 0.028) than long-duration exercises (SMD 0.20; p = 0.64). Children have higher endurance and are less fatigable than adults. These differences are influenced by the exercise modality, suggesting distinct physiological functioning during exercise between children and adults. The low number of studies comparing these outcomes between adolescents versus children and adults prevents robust conclusions and warrants further investigations in adolescent individuals.

The Interactive Effects of Post-Traumatic Stress Symptoms and Breathlessness on Fatigue Severity in Post-COVID-19 Syndrome

Background: Post-traumatic stress symptoms (PTSS) and breathlessness have been well documented in the acute phase of COVID-19 as well as in Post-COVID-19 Syndrome (PCS), commonly known as Long-COVID. The present study aimed to explore whether PTSS and breathlessness interact to exacerbate fatigue among individuals recovering from PCS, similar to the effects evidenced in other health conditions that feature respiratory distress.. Methods: Outcome measures were collected from 154 participants reporting persistent fatigue following acute COVID-19 infection who were enrolled in a 7-week rehabilitation course provided by the Primary Care Wellbeing Service (PCWBS) in Bradford District Care NHS Foundation Trust (BDCFT). Results: Hierarchical multiple linear regression revealed that fatigue severity was associated with a significant interaction between PTSS and breathlessness, even when controlling for pre-COVID health related quality of life (HRQoL), age, symptom duration and hospital admittance during the acute phase. Furthermore, improvements in fatigue following rehabilitation were significantly associated with improvements in PTSS. Conclusions: PTSS may be an important therapeutic target in multidisciplinary rehabilitation for reducing fatigue in the recovery from PCS. It is therefore important that treatment for PCS takes a biopsychosocial approach to recovery, putting emphasis on direct and indirect psychological factors which may facilitate or disrupt physical recovery. This highlights the need for all PCS clinics to screen for PTSD and if present, target as a priority in treatment to maximise the potential for successful rehabilitation.

Experiences of fatigue among people with chronic obstructive pulmonary disease: a qualitative systematic review protocol

OBJECTIVE

The objective of this review is to explore the experiences of adults with chronic obstructive pulmonary disease living with fatigue.

INTRODUCTION

Chronic obstructive pulmonary disease is an incurable disease that causes multiple physical, social, and psychological burdens to those affected as well as their caregivers. One symptom that affects the quality of life of people with chronic obstructive pulmonary disease is fatigue. However, the experiences of fatigue disclosed by people with chronic obstructive pulmonary disease have not been widely documented in previous reviews. The findings of this review will provide insights into how people with chronic obstructive pulmonary disease experience fatigue, which will be useful for developing, targeting, and implementing needs-based counseling interventions to help them deal with fatigue and maintain functioning.

INCLUSION CRITERIA

This review will consider studies that include adults (>18 years) with chronic obstructive pulmonary disease at any stage, and that focus on the experiences of fatigue in any context, including health services (in- and out-patient), community, work, leisure, and home.

METHODS

MEDLINE, CINAHL, PsycINFO, Academic Search Premier, Web of Science, Medic, OpenGrey, and ProQuest Dissertation and Theses will be searched for relevant published and unpublished literature with no restrictions on publication date. Study selection, quality appraisal, and data extraction will be conducted by 2 independent reviewers. Eligible studies will be evaluated using the JBI critical appraisal tool for qualitative research. Findings will be pooled using the JBI method of meta-aggregation, and a level of credibility will be assigned to the findings. The findings will be graded according to the ConQual approach for establishing confidence in findings.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42021242227.

Relationship between perceived and neuromuscular fatigue in COPD patients with chronic respiratory failure with long-term oxygen therapy: a cross-sectional study

PURPOSE

To evaluate perceived fatigue (PF) and neuromuscular fatigue (NMF) in patients with COPD and chronic respiratory failure (CRF) on long-term oxygen therapy (CRF-COPD group), and the relationships between PF, NMF, patient's characteristics, comparing severe patients with COPD to patients without CRF (COPD group).

METHODS

This cross-sectional study compared 19 CRF-COPD patients with 10 COPD patients attending a rehabilitation program. PF was determined by Fatigue Severity Scale (FSS), while dyspnea by the Barthel Dyspnea Index (BDI). We assessed quadriceps NMF via electrical nerve stimulation during and following a Maximal Voluntary Contraction (MVC) detecting changes after a Constant Workload Cycling Test (CWCT) at 80% of the peak power output at exhaustion.

RESULTS

CRF-COPD patients showed higher PF (+ 1.79 of FSS score, p = 0.0052) and dyspnea (+ 21.03 of BDI score, p = 0.0023) than COPD patients. After the fatiguing task and normalization for the total work, there was a similar decrease in the MVC (CRF-COPD -1.5 ± 2.4 vs COPD -1.1 ± 1.2% baseline kJ^-1, p = 0.5819), in the potentiated resting twitch force (CRF-COPD -2.8 ± 4.7 vs COPD -2.0 ± 3.3% baseline kJ^-1, p = 0.7481) and in the maximal voluntary activation (CRF-COPD -0.1 ± 3.9 vs COPD -0.9 ± 1.2 -2.0 ± 3.3% baseline kJ^-1, p = 0.4354). FSS and BDI were closely related (R = 0.5735, p = 0.0011), while no correlation between PF and NMF was found.

CONCLUSION

Patients with CRF-COPD develop higher levels of perceived fatigue and dyspnea than patients with COPD; while neuromuscular fatigue is similar, suggesting a mismatch between symptoms and neuromuscular dysfunction.

Influence of an Upper Limb Isometric Task in Perceived and Performance Fatigability of Elderly Subjects: A Quasi-Experimental Study

Isometric activity can be used as a strategy to improve health, fitness, and functional performance in the elderly population, but differences in fatigability may occur. This study aimed to understand fatigability behavior during an upper limb isometric task (ULIT) and the role of health status and physical activity in the fatigability of elderly participants. Thirty-two (32) elderly participants (72.5 ± 5.18 years) were instructed to perform ULIT. The Borg CR10 scale and task failure point (TTF) were used to measure perceived and performance fatigability. Self-reported measures were used to assess the quality of life and physical activity level. A significant relationship between perceived and performance fatigability was found only in the final phase of activity (p < 0.01). Significant correlations were found between perceived fatigability and the social functioning dimension (p < 0.05), and between performance fatigability (TTF) and BMI (p < 0.01), physical functioning (p < 0.01), and role functioning/physical (p < 0.05) dimensions. In conclusion, ULIT produces changes in fatigability of elderly people, which are positively related in the final stage of the activity. Changes in fatigability are negatively related to BMI. It is also negatively related to health, social functioning, physical functioning and role functioning/physical quality of life dimensions.

Growth Differentiation Factor-15 as a Biomarker for Sarcopenia in Patients With Chronic Obstructive Pulmonary Disease

Purpose

Sarcopenia is an important factor contributing to comorbidities in patients with chronic obstructive pulmonary disease (COPD) and is an independent risk factor for increased mortality. The diagnostic process for sarcopenia requires specific equipment and specialized training and is difficult procedurally. A previous study found that GDF15 levels are associated with skeletal muscle mass and function in patients with COPD. However, whether circulating GDF15 levels can be used for the prediction of sarcopenia in patients with COPD is unknown.

Methods

This study included 235 patients with stable COPD who were divided into a development set (n = 117) and a validation set (n = 118), and we followed the definition of sarcopenia as defined by the guidelines from the Asian Working Group for Sarcopenia. Serum concentrations of GDF15 were measured using an enzyme-linked immunosorbent assay (ELISA), and construction of a nomogram and decision curve analysis were performed using the R package “rms.”

Results

In this study, serum GDF15 levels were negatively associated with skeletal muscle mass (r = –0.204, p = 0.031), handgrip strength (r = –0.274, p = 0.004), quadriceps strength (r = –0.269, p = 0.029), and the thickness (r = –0.338, p < 0.001) and area (r = –0.335, p < 0.001) of the rectus femoris muscle in patients with COPD. Furthermore, the serum levels of GDF15 in patients with sarcopenia were significantly higher than those in controls. Importantly, serum levels of GDF15 could effectively predict sarcopenia in patients with COPD based on the development set (AUC = 0.827) and validation set (AUC = 0.801). Finally, a nomogram model based on serum GDF15 levels and clinical features showed good predictive ability (AUC > 0.89) in the development and validation sets.

Conclusion

Serum GDF15 levels could be used to accurately and easily evaluate sarcopenia in patients with COPD.

How Do Sleep Disturbances Relate to Daytime Functions, Care-related Quality of Life, and Parenting Interactions in Mothers of Children with Autism Spectrum Disorder?

Sleep disturbance is prevalent in caregivers and associated with negative physical, mental, and functional outcomes. This study examined the effects of sleep disturbance on daytime functions (sleepiness, fatigue, mood, cognitive alertness), care-related quality of life, and daily parenting interactions in 20 mothers of children with autism spectrum disorder for 10 consecutive days using ecological momentary assessment design. Participants responded about daytime functions four times and care-related quality of life and daily parenting interactions once using an online survey. Sleep disturbance was significantly related to all daytime functions and frustration with childcare. Therefore, development of sleep hygiene interventions is warranted to effectively reduce the impact of sleep disturbance and enable these mothers to better tackle daily physical and mental challenges.

One-year evolution of DLCO changes and respiratory symptoms in patients with post COVID-19 respiratory syndrome

Purpose

During a follow-up program of patients admitted for COVID-19 at our non-ICU Unit, we found that 37% of them had decreased diffusing lung capacity for carbon monoxide (DLCO) 3–6 months after discharge. This prospective observational study aimed to evaluate the evolution of changes in DLCO and respiratory symptoms at the 1-year follow-up visit.

Methods

Seventeen (mean age 71 years; 8 males) of 19 eligible patients (DLCO < 80% of predicted at the 3–6 months follow-up visit) completed the 1-year follow-up visit. One patient refused to participate and 1 patient had died 3 months earlier from myocardial infarction. The visit included a self-reported structured questionnaire, physical exam, blood tests, ECG, and spirometry with DLCO.

Results

Mean DLCO was significantly improved at the 1-year visit (from 64% of predicted at 3–6 months to 74% of predicted at 1 year; P = 0.003). A clinically significant increase in DLCO (10% or greater) was observed in 11 patients (65%) with complete normalization (> 80% of predicted) in 6 (35%); in the other 6 (35%) it remained unchanged. The prevalence of exertional dyspnea (65–35%, P = 0.17), cough (24–18%, P = 1), and fatigue (76–35%, P = 0.04) decreased at the 1-year visit.

Conclusion

These results suggest that DLCO and respiratory symptoms tend to normalize or improve 1 year after hospitalization for COVID-19 in most patients. However, there is also a non-negligible number of patients (about one-third) in whom respiratory changes persist and will need prolonged follow-up.

The Exercising Brain: An Overlooked Factor Limiting the Tolerance to Physical Exertion in Major Cardiorespiratory Diseases?

“Exercise starts and ends in the brain”: this was the title of a review article authored by Dr. Bengt Kayser back in 2003. In this piece of work, the author highlights that pioneer studies have primarily focused on the cardiorespiratory-muscle axis to set the human limits to whole-body exercise tolerance. In some circumstances, however, exercise cessation may not be solely attributable to these players: the central nervous system is thought to hold a relevant role as the ultimate site of exercise termination. In fact, there has been a growing interest relative to the “brain” response to exercise in chronic cardiorespiratory diseases, and its potential implication in limiting the tolerance to physical exertion in patients. To reach these overarching goals, non-invasive techniques, such as near-infrared spectroscopy and transcranial magnetic stimulation, have been successfully applied to get insights into the underlying mechanisms of exercise limitation in clinical populations. This review provides an up-to-date outline of the rationale for the “brain” as the organ limiting the tolerance to physical exertion in patients with cardiorespiratory diseases. We first outline some key methodological aspects of neuromuscular function and cerebral hemodynamics assessment in response to different exercise paradigms. We then review the most prominent studies, which explored the influence of major cardiorespiratory diseases on these outcomes. After a balanced summary of existing evidence, we finalize by detailing the rationale for investigating the “brain” contribution to exercise limitation in hitherto unexplored cardiorespiratory diseases, an endeavor that might lead to innovative lines of applied physiological research.

Experienced fatigue in people with rare disorders: a scoping review on characteristics of existing research

BACKGROUND

Experienced fatigue is an under-recognized and under-researched feature in persons with many different rare diseases. A better overview of the characteristics of existing research on experienced fatigue in children and adults with rare diseases is needed. The purpose of this review was to map and describe characteristics of existing research on experienced fatigue in a selection of rare diseases in rare developmental defects or anomalies during embryogenesis and rare genetic diseases. Furthermore, to identify research gaps and point to research agendas.

METHODS

We applied a scoping review methodology, and performed a systematic search in March 2020 in bibliographic databases. References were sorted and evaluated for inclusion using EndNote and Rayyan. Data were extracted on the main research questions concerning characteristics of research on experienced fatigue (definition and focus on fatigue, study populations, research questions investigated and methods used).

RESULTS

This review included 215 articles on ten different rare developmental defects/anomalies during embryogenesis and 35 rare genetic diseases. Of the 215 articles, 82 had investigation of experienced fatigue as primary aim or outcome. Included were 9 secondary research articles (reviews) and 206 primary research articles. A minority of articles included children. There were large differences in the number of studies in different diseases. Only 29 of 215 articles gave a description of how they defined the concept of experienced fatigue. The most common research-question reported on was prevalence and/ -or associations to fatigue. The least common was diagnostics (development or validation of fatigue assessment methods for a specific patient group). A large variety of methods were used to investigate experienced fatigue, impeding comparisons both within and across diagnoses.

CONCLUSION

This scoping review on the characteristics of fatigue research in rare diseases found a large variety of research on experienced fatigue. However, the minority of studies had investigation of experienced fatigue as a primary aim. There was large variation in how experienced fatigue was defined and also in how it was measured, both within and across diagnoses. More research on experienced fatigue is needed, both in children and adults with rare diseases. This review offers a basis for further research.

Relationships between Physiological and Self-Reported Assessment of Cancer-Related Fatigue

The purpose of this study was to evaluate the relationships between subjective, self-reported cancer related fatigue (CRF) and objective measures of muscular strength and fatigability in cancer survivors. A total of 155 cancer survivors (60 ± 13 years of age) completed a questionnaire for the assessment of CRF, along with assessments of handgrip strength, quadriceps strength and fatigability (reduced force/torque). Fatigability was measured by completing 15 maximal isokinetic contractions of the knee extensors (QFI). Spearman's rho correlation coefficients were calculated as pairwise combinations of the numerical and categorical dependent measures. Categorical variables were analyzed via nonparametric means of association. This included a 4×4 chi-square to test whether cancer stage (0-4) was independent of fatigue status (none, mild, moderate, severe) and whether cancer treatment (surgery, radiation, chemotherapy, or combinations of these) was independent of fatigue status. None of the physiological strength and fatigue measures were significantly correlated to overall perceived fatigue or any of the subscales. Cancer stage and treatment type were also not significantly related to fatigue status (likelihood ratio = .225, Cramer's V = .228; likelihood ratio = .103, Cramer's V = .369, respectively). Our results show that levels of patient reported fatigue severity were not significantly related to muscular fatigability or strength. As a result, cancer patients experiencing fatigue may benefit from following the standard exercise guidelines for cancer survivors, regardless of their levels of self-reported fatigue.

Rethinking physical exercise training in the modern era of cystic fibrosis: A step towards optimising short-term efficacy and long-term engagement

Exercise is considered as an important component of the package of care delivered to people with cystic fibrosis (pwCF). However, despite the well-known short-term physiological and psychological benefits, training effects are heterogenous and the transfer of structured exercise programmes to the daily life of pwCF is challenging. Training concepts and strategies developed over the last decades must be adapted to consider the aging population of pwCF with associated comorbidities, and also a new generation of young pwCF that are healthier than ever. In the present review we propose a new framework for optimising the choice among available exercise training procedures and we provide a theoretical and scientifically justified rationale for considering and testing new exercise training modalities. We propose a multidisciplinary approach, considering various physiological, psychological and logistical factors, with the aim to increase effects of exercise training and build positive long-term exercise behaviour.

Nutritional therapy for patients with coronavirus disease 2019 (COVID-19): Practical protocol from a single center highly affected by an outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection

OBJECTIVES

Coronavirus disease 2019 (COVID-19) carries a high risk for malnutrition owing to the state of debilitation that results from acute respiratory failure symptoms. The aim of this study was to provide an approach to reduce the risk for malnutrition and improve patients' clinical outcomes.

METHODS

Short age-adjusted Nutritional Risk Screening was performed with 94 non-intensive care unit (ICU) patients admitted to the Giovanni Borea Civil Hospital in Sanremo. Forty-nine patients in the ICU were considered at risk for malnutrition without screening and were fed with enteral nutrition plus supplemental parenteral nutrition. In the non-ICU setting, patients underwent a personalized nutritional protocol, considering their conditions, which consisted of a high-protein and high-calorie pureed diet, oral nutritional supplements, and/or artificial nutrition or other personalized nutritional path.

RESULTS

The nutritional treatment was well tolerated by the patients. Of the non-ICU patients, 19.1% died. They were mainly women, with higher body mass indices and older in age. Of the patients in the ICU, 53.1% died. Of the 94 non-ICU patients, 72 scored positive on at least one nutritional risk screening item (excluding age). Of the 94 non-ICU patients, 68 were >70 y of age. Non-ICU patients whose energy and protein needs were not met were older (P = 0.01) and had a higher death rate than patients whose needs were met (P < 0.001).

CONCLUSIONS

This protocol should not be considered as a guideline; rather, it is intended to report the clinical experience of a nutrition team in an Italian reference center for the treatment of patients with COVID-19. Nutritional strategies should be implemented to prevent worsening of clinical outcomes.

Factors affecting the severity of fatigue in male patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVES

Fatigue, the second most common symptom after dyspnea in patients with chronic obstructive pulmonary disease, impairs functional capacity and quality of life. This study aims to predict the factors that affect fatigue severity and investigate the effects of fatigue in patients with chronic obstructive pulmonary disease.

METHODS

Data were collected to assess demographic and clinical characteristics, cigarette consumption, fatigue severity (Fatigue Severity Scale), dyspnea severity (Medical Research Council Dyspnea Scale), level of physical activity (International Physical Activity Questionnaire-Short Form), and health-related quality of life (36-Item Short Form Health Survey).

RESULTS

A total of 64 male chronic obstructive pulmonary disease patients were evaluated (mean age 61.1±4.7 years, mean Fatigue Severity Scale score 39.8±14.4). The result of the linear regression model was significant and explained 84% of the variance in fatigue severity (Adjusted R-squared=0.84, F=29.48, df=60, p<.001). It showed that the Medical Research Council Dyspnea Scale score (β=.40), cigarette consumption (β=.35), and physical activity level (β=-.37) were significantly correlated with the severity of fatigue (p<.001 for all) and that they independently contributed to the prediction of severity of fatigue.

CONCLUSION

Dyspnea, cigarette consumption, and physical activity level affect fatigue severity. Additionally, physical activity level, pulmonary function, and health-related quality of life were also associated with fatigue. These findings support the assertion that it is important to measure fatigue and the factors that affect its severity.

Factors affecting the severity of fatigue in male patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVES

Fatigue, the second most common symptom after dyspnea in patients with chronic obstructive pulmonary disease, impairs functional capacity and quality of life. This study aims to predict the factors that affect fatigue severity and investigate the effects of fatigue in patients with chronic obstructive pulmonary disease.

METHODS

Data were collected to assess demographic and clinical characteristics, cigarette consumption, fatigue severity (Fatigue Severity Scale), dyspnea severity (Medical Research Council Dyspnea Scale), level of physical activity (International Physical Activity Questionnaire Short-Form), and health-related quality of life (36-Item Short Form Health Survey).

RESULTS

A total of 64 male COPD patients were evaluated (mean age 61.1 ± 4.7 years, mean FSS score 39.8 ± 14.4). The result of the linear regression model was significant and explained 84% of the variance in fatigue severity (Adjusted R-squared = 0.84, F = 29.48, df = 60, p < .001). It showed that the MRC score (β = .40), cigarette consumption (β = .35), and physical activity level (β = -.37) were significantly correlated with the severity of fatigue (p < .001 for all) and that they independently contributed to the prediction of severity of fatigue.

CONCLUSION

Dyspnea, cigarette consumption, and physical activity level affect fatigue severity. Additionally, physical activity level, pulmonary function, and HRQOL were also associated with fatigue. These findings support the assertion that it is important to measure fatigue and the factors that affect its severity.

Extra-pulmonary manifestations of COPD and the role of pulmonary rehabilitation: a symptom-centered approach

Introduction: Chronic obstructive pulmonary disease (COPD) is a complex and heterogenous disease that is associated with a range of respiratory and non-respiratory symptoms, which highly contribute to the daily burden of the disease. Symptoms burden remains high despite optimal bronchodilator therapy, but pulmonary rehabilitation (PR) is an effective intervention to improve patients' symptoms. A comprehensive interdisciplinary approach within the framework of a PR program is warranted to tackle these complex symptoms and their consequences. Areas covered: This narrative review describes how symptoms of dyspnea, fatigue, cough, sputum, anxiety, depression, pain, sleep disturbances, and cognitive decline arise in COPD and can contribute to several non-pulmonary manifestations of the disease. It also describes evidence of the effectiveness of interdisciplinary PR programs to counteract these symptoms. A literature search was performed on PubMed and Scopus between June and July 2020. Expert opinion: Respiratory and non-respiratory symptoms are highly prevalent, often not comprehensively assessed, and result in several extra-pulmonary manifestations of the disease (physical, emotional and social). Interdisciplinary PR programs can improve these negative manifestations through different pathways, contributing for an effective symptoms' management. A thorough assessment of symptoms (beyond dyspnea) should be routinely performed and may support the identification of treatable traits, allowing the tailoring of PR interventions and assessment of their real-life impact.

The role of peripheral muscle fatigability on exercise intolerance in COPD

INTRODUCTION

Exercise limitation in chronic obstructive pulmonary disease (COPD) is multi-factorial; however, growing evidence indicates that muscle dysfunction may contribute in some patients.

AREAS COVERED

This work outlines current evidence for and against increased peripheral muscle fatigability in COPD through a comprehensive review of relevant literature available on PubMed/MEDLINE until May 2020. The authors first discuss key methodological issues relative to muscle fatigue assessment by non-volitional techniques, particularly magnetic stimulation. The authors then provide a detailed discussion of critical studies to have objectively measured skeletal muscle fatigue in individuals with COPD.

EXPERT OPINION

Current evidence indicates that localized (knee extension) and cycling exercise are associated with increased quadriceps fatigability in most COPD patients. Increased fatigability, however, has not been consistently found in response to walking, likely reflecting the tendency of 'central' respiratory constraints to overshadow potential functional impairments in the appendicular muscles in this form of exercise. Thus, addressing skeletal muscle abnormalities may be critical to translate improvements in lung mechanics (e.g., due to bronchodilator therapy) into better exercise tolerance. The positive effects of pulmonary rehabilitation on muscle fatigability are particularly encouraging and suggest a role for these measurements to test the efficacy of emerging adjunct training strategies focused on the peripheral muscles.

Efficacy of adding activity of daily living simulation training to traditional pulmonary rehabilitation on dyspnea and health-related quality-of-life

Introduction

Exercise modalities offered as part of traditional pulmonary rehabilitation (PR) do not always translate to successful performance of Activities of Daily Living (ADL) and may hinder gains in patient’s sense of well-being. Data is lacking on the efficacy of incorporation of ADL-focused training in PR. The aim of this study was to determine the impact of incorporation of ADL simulation and energy-conservation training in PR as part of a quality-initiative on health-related-quality-of-life (HRQOL), dyspnea, fatigue, and six-minute-walk-test among PR patients.

Methods

Retrospective study where medical records of consecutive patients with chronic respiratory diseases who completed PR from 2016 to 2018 were reviewed. ADL-focused energy-conservation training was added to traditional PR in September 2017 by replacing three monthly sessions of traditional PR with energy-conservation training as a quality-improvement-initiative. The change from baseline on HRQOL measured by COPD assessment test (CAT), six-minute-walk-test, MMRC dyspnea score and CRQ-dyspnea and CRQ-fatigue questionnaires, were compared between patients who received traditional PR versus energy-conservation PR. Within and between group differences were calculated via repeated-measures ANOVA.

Results

The baseline characteristics of 91 patients who participated in traditional PR versus energy-conservation PR (n = 85) were similar (mean age = 68.6±10.4 years, 49% men). While improvement from baseline was similar and significant for both groups for MMRC, CRQ-dyspnea and CRQ-fatigue scores, and six-minute walk test, patients who participated in energy-conservation PR had significantly higher improvement in HRQOL CAT scores (p = 0.01) than those who completed traditional PR.

Conclusion

Tailoring patient’s training programs to include energy-conservation training exercises specific to ADL in PR improved HRQOL over traditional PR in patients with chronic respiratory diseases despite no significant change in functional status. Future randomized-controlled trials will be needed to confirm these initial findings.

Is bilateral corticospinal connectivity impaired in patients with chronic obstructive pulmonary disease?

KEY POINTS

During moderate and high levels of quadriceps force production, the ipsilateral motor cortex is concomitantly activated with the contralateral motor cortex throughout the corpus callosum to generate the motor command. Chronic obstructive pulmonary disease (COPD) patients display a structurally impaired corpus callosum that may explain the reduced motor command in this population, which in turn contributes to COPD-related muscle weakness of the knee extensors. The study aimed to determine whether bilateral connectivity was impaired and ipsilateral activation was lowered during unilateral strength production of the knee extensors. Our results indicate impaired bilateral connectivity but preserved ipsilateral activation in patients during unilateral isometric contractions of 50% of maximum voluntary strength. The preservation of ipsilateral activation during force production despite impaired bilateral connectivity is consistent with a reorganization of bilateral motor network function that drives unilateral strength production.

ABSTRACT

The contralateral primary motor cortex (M1) is not the only brain area implicated in motor command generation. During moderate and high levels of quadriceps force production, the ipsilateral M1 is concomitantly activated. Such activation is mediated by the corpus callosum, the main component of bilateral connectivity. Structural damage to the corpus callosum has been observed in chronic obstructive pulmonary disease (COPD) patients, which might reduce ipsilateral activation and contribute to the lower motor command associated with COPD muscle weakness. We thus aimed to determine whether bilateral connectivity and ipsilateral activation were impaired in COPD. Twenty-two COPD patients and 21 healthy age-matched controls were evaluated by transcranial magnetic stimulation, at rest and during 50% of maximal voluntary isometric contraction (MVIC) of the dominant vastus lateralis muscle. Bilateral connectivity was determined by the ipsilateral silent period (iSP) during 50% MVIC. Ipsilateral activation was determined as the increase in ipsilateral excitability from rest to 50% MVIC. As expected, COPD patients had significantly lower MVIC (-25%, p = 0.03). These patients also showed a significantly lower iSP (-53%, p < 0.001) compared to controls. The ipsilateral excitability was increased in patients and controls (×2.5 and ×3.5, respectively, p < 0.001) but not differently between groups (p = 0.84). Despite impaired bilateral connectivity in COPD, ipsilateral activation was not increased. Reorganization in the patients' interhemispheric pathways could explain the preserved ipsilateral activation.

Clinimetric evaluation of muscle function tests for individuals with cystic fibrosis: A systematic review

Accurate testing of muscle function is essential in individuals with cystic fibrosis (CF). A literature search was conducted in MEDLINE, CENTRAL, CINAHL, PEDro, ScienceDirect and Web of Science according to PRISMA and COSMIN guidelines from inception to September 2019 to investigate the clinimetric properties of muscle tests in individuals with CF. The search identified 37 studies (1310 individuals) and 34 different muscle tests. Maximal inspiratory pressure, inspiratory work capacity and quadriceps strength measured by computerised dynamometry were identified as reliable tests of muscle function. The one-minute sit-to-stand test was found to have high reliability but its validity to measure quadriceps strength is unknown. The clinimetric properties of other routinely used tests have not been reported in people with CF. Very different measurement procedures were identified. Inspiratory muscle and quadriceps testing can be considered as reliable but high-quality studies evaluating tests of other muscles function (e.g. muscle endurance) are lacking.

Walking Training Enhances Corticospinal Excitability in Progressive Multiple Sclerosis-A Pilot Study

Background: Inflammatory lesions and neurodegeneration lead to motor, cognitive, and sensory impairments in people with multiple sclerosis (MS). Accumulation of disability is at least partially due to diminished capacity for neuroplasticity within the central nervous system. Aerobic exercise is a potentially important intervention to enhance neuroplasticity since it causes upregulation of neurotrophins and enhances corticospinal excitability, which can be probed using single-pulse transcranial magnetic stimulation (TMS). Whether people with progressive MS who have accumulated substantial disability could benefit from walking rehabilitative training to enhance neuroplasticity is not known.

Objective: We aimed to determine whether 10 weeks of task-specific walking training would affect corticospinal excitability over time (pre, post, and 3-month follow-up) among people with progressive MS who required walking aids.

Results: Eight people with progressive MS (seven female; 29–74 years old) with an Expanded Disability Status Scale of 6–6.5 underwent harness-supported treadmill walking training in a temperature controlled room at 16°C (10 weeks; three times/week; 40 min at 40–65% heart rate reserve). After training, there was significantly higher corticospinal excitability in both brain hemispheres, reductions in TMS active motor thresholds, and increases in motor-evoked potential amplitudes and slope of the recruitment curve (REC). Decreased intracortical inhibition (shorter cortical silent period) after training was noted in the hemisphere corresponding to the stronger hand only. These effects were not sustained at follow-up. There was a significant relationship between increases in corticospinal excitability (REC, area under the curve) in the hemisphere corresponding to the stronger hand and lessening of both intensity and impact of fatigue on activities of daily living (Fatigue Severity Scale and Modified Fatigue Impact Scale, respectively).

Conclusion: Our pilot results support that vigorous treadmill training can potentially improve neuroplastic potential and mitigate symptoms of the disease even among people who have accumulated substantial disability due to MS.

Managing Fatigue in Patients With Interstitial Lung Disease

Fatigue is one of the most burdensome symptoms in interstitial lung disease (ILD) and can have a major impact on quality of life, social interactions, and work capacity. The cause of fatigue is complex; it is caused or aggravated by a combination of different predisposing, precipitating, and perpetuating factors. There is no uniform definition of fatigue, but it is often divided in physical and mental components. Several validated questionnaires can be used for structural assessment of fatigue in daily care. Although the high burden of fatigue in ILD is recognized increasingly, studies that have investigated pharmacologic and nonpharmacologic treatment options are scarce. Because fatigue in ILD is often a multifactorial problem, therapeutic interventions ideally should be aimed at different domains. One of the first steps is to optimize treatment of the underlying disease. Subsequently, treatable causes of fatigue should be identified and treated. Recently, an increasing number of studies showed that supportive measures have the potential to improve fatigue. However, evidence-based treatment guidelines are lacking, and more research is highly needed in this field. In clinical practice, a comprehensive, multidisciplinary, and individually tailored approach seems best fit to optimize treatment of fatigue in patients with ILD.

Influence of sex gap on muscle strength and functional mobility in patients with cystic fibrosis

The objectives of this study were to determine whether there were differences in handgrip strength and functional mobility between patients with cystic fibrosis (CF) and healthy controls with regard to sex and to ascertain whether these differences were related to lung function. Thirty-eight patients with CF (21 women) and 38 healthy controls aged 18–65 years were included. Muscle weakness and functional mobility were assessed through handgrip strength; walking speed; and time, velocity, and power derived from a single sit-to-stand (STS) test. Patients with CF showed differences for STS variables and walking speed but not for handgrip strength, compared with healthy controls. Considering sex differences, female patients showed differences for all variables analyzed while males with CF only exhibited differences for STS variables, compared with healthy controls. Females with CF showed moderate relationship between muscle weakness, functional mobility, and lung function (|r| = 0.45–0.49; p ≤ 0.05) whereas no relationships were observed for males with CF. The influence of chronic infection with Pseudomonas aeruginosa and pancreatic insufficiency on muscle weakness and functional mobility was similar in both sexes. Differences in muscle strength and functional mobility were predominantly observed in females with CF. These results suggest an important effect of sex gap on muscle weakness and functional mobility in patients with CF.

Novelty The influence of sex gap on muscle weakness in CF has been shown. Muscle weakness was predominantly observed in females with CF.

Minimal Clinically Important Differences for Patient-Reported Outcome Measures of Fatigue in Patients With COPD Following Pulmonary Rehabilitation

BACKGROUND

Fatigue is a burdensome and prevailing symptom in patients with COPD. Pulmonary rehabilitation (PR) improves fatigue; however, interpreting when such improvement is clinically relevant is challenging. Minimal clinically important differences (MCIDs) for instruments assessing fatigue are warranted to better tailor PR and guide clinical decisions.

RESEARCH QUESTION

This study estimated MCIDs for the Functional Assessment of Chronic Illness Therapy-Fatigue Subscale (FACIT-FS), the modified FACIT-FS, and the Checklist Individual Strength-Fatigue Subscale in patients with COPD following PR.

STUDY DESIGN AND METHODS

Data from patients with COPD who completed a 12-week community-based PR program were used to compute the MCIDs. The pooled MCID was estimated by calculating the arithmetic weighted mean, resulting from the combination of anchor-based (weight, two-thirds) and distribution-based (weight, one-third) methods. Anchors were patients' and physiotherapists' Global Rating of Change Scale, COPD Assessment Test, St. George's Respiratory Questionnaire (SGRQ), and exacerbations. To estimate MCIDs, we used mean change, receiver-operating characteristic curves, and linear regression analysis for anchor-based approaches, and 0.5 × SD, SE of measurement, 1.96 × SE of measurement, and minimal detectable change for distribution-based approaches.

RESULTS

Fifty-three patients with COPD (79% male, 68.4 ± 7.6 years of age, and FEV₁ 48.7 ± 17.4% predicted) were included in the analysis. Exacerbations and the SGRQ-impact and the SGRQ-total scores fulfilled the requirements to be used as anchors. Pooled MCIDs were 4.7 for FACIT-FS, 3.8 for the modified FACIT-FS, and 9.3 for the Checklist Individual Strength-Fatigue Subscale.

INTRPRETATION

The MCIDs proposed in this study can be used by different stakeholders to interpret PR effectiveness.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT03799666; URL: www.clinicaltrials.gov.

Multimorbidity in COPD, does sleep matter?

A good night's sleep is a prerequisite for sustainable mental and physical health. Sleep disorders, including sleep disordered breathing, insomnia and sleep related motor dysfunction (e.g., restless legs syndrome), are common in patients with chronic obstructive pulmonary disease (COPD), especially in more severe disease. COPD is commonly associated with multimorbidity, and sleep disorders as a component of this multimorbidity spectrum have a further negative impact on COPD-related comorbidities. Indeed, concomitant diseases in COPD and in obstructive sleep apnea (OSA) are similar, suggesting that the combination of COPD and OSA, the so called OSA-COPD overlap syndrome (OVS), affects patient outcomes. Potential clinically important interactions of OVS exist in cardiovascular and metabolic disease, arthritis, anxiety, depression, neurocognitive disorder and the fatigue syndrome. Correct diagnosis for recognition and treatment of sleep-related disorders in COPD is recommended. However, surprisingly limited information is available and further research and improved diagnostic tools are needed. In the absence of clear evidence, we agree with the recommendation of the Global Initiative on Chronic Obstructive Lung Disease that sleep disorders should be actively searched for and treated in patients with COPD. We believe that both aspects are important components of the holistic approach required in patients with chronic multimorbid conditions.

Perceptions towards physical activity in adult lung transplant recipients with cystic fibrosis

Background

Barriers and motives towards physical activity (PA) in lung transplant (LTx) recipients with cystic fibrosis (CF) are largely unknown. We aimed to explore perceptions towards PA in LTx recipients with CF to better understand individuals’ needs and preferences.

Methods

Participants completed an online survey at two Swiss LTx and one follow-up shared care centre between June and December 2018.

Results

One hundred and eleven individuals completed the survey (87.4% response rate). Overall, survey participants perceive PA as important for their daily life and health. Perceived motives of PA were improving muscle strength, endurance and quality of life (QoL), to feel better, fun, to achieve personal goals and having more energy for everyday life. Fatigue was the most common perceived barrier to PA and associated with poorer QoL (r = -0.43, p<0.001) and health status (r = -0.31, p = 0.001). Participants with lung allograft dysfunction (LAD, n = 20) reported lower habitual PA (p = 0.009) and health status (p = 0.011), and rated shortness of breath, bad weather and concerns regarding lung rejection higher than those without LAD (all p<0.05). When we asked how an optimal training programme should look like, the majority would prefer individual, non-supervised (60%), outdoor (77%), endurance training (90%), once or twice a week (47%) for 40–60 minutes (48%). Only a minority of patients (14%) would be willing to use exercise applications for their home-based training.

Conclusions

LTx recipients with CF value PA as important for their health. People with CF should be encouraged individually by their multidisciplinary transplant team to implement PA in their daily life, potential barriers should be identified and addressed. Overall, knowledge on perceived barriers and motives for PA should be considered in the development of future patient-centred PA programmes.

A randomized controlled trial of respiratory physiotherapy in lower respiratory tract infections

INTRODUCTION

Physiotherapy may play a role in the recovery of signs, symptoms and function of patients with lower respiratory tract infections (LRTI) but its effectiveness is still controversial.

OBJECTIVES

To assess the effects of respiratory physiotherapy compared with standard pharmacological care on symptoms and function in outpatients with LRTI.

DESIGN

Single-blind, randomised controlled trial.

SETTING

Outpatients were recruited from the casualties of a central hospital.

PARTICIPANTS

Outpatients with LRTI were recruited and randomly allocated to the control (pharmacological) or experimental (pharmacological and respiratory physiotherapy) group.

INTERVENTION

The intervention consisted of conventional pharmacological treatment and conventional pharmacological treatment plus respiratory physiotherapy. Respiratory physiotherapy included breathing and airway clearance techniques, exercise training and education during 3-weeks, 3 times per week.

MAIN OUTCOME MEASURE

Primary outcome measures - occupation rate of wheezes Wh%; Secondary outcome measures - number of crackles, peripheral oxygen saturation (SpO2) modified Borg scale (mBorg), modified Medical Research Council scale (mMRC), 6-min walk test (6MWT), forced expiratory volume in 1 s and forced vital capacity, and volume and density of the lung and bronchial tree volume.

RESULTS

Ninety-seven patients (53 controls and 44 experimental) completed the intervention. After the intervention, both groups improved significantly in all variables (0.0001 < p < 0.04; 0.001<ƞ²<0.092), with the exception of the mBorg. The magnitude of improvement of the experimental group exceeded the control group in the number of crackles, SpO2 levels, mMRC and 6MWT (0.002 < p < 0.032; 0.002<ƞ²<0.092).

CONCLUSION

Adding respiratory physiotherapy to the pharmacological treatment of outpatients with LRTI results in greater recovery of symptoms and function parameters.

TRIAL REGISTRATION

NCT02053870.

The holistic management of fatigue within palliative care

BACKGROUND

Fatigue is a common symptom experienced by people with cancer and other long-term, non-malignant conditions. It can be disease-related or caused by treatments such as chemotherapy or radiotherapy. Patients frequently report this as a distressing symptom and, while some international guidelines for its management exist, evidence suggests that these are not always implemented.

METHOD

This article reviews the evidence basis for fatigue management, looking at exercise, education, psychological interventions, complementary therapies and pharmacological therapy, and finds that a one-size fits all approach to fatigue management is unrealistic.

FINDINGS

Research appears to support different interventions at various points in the disease trajectory and this is of importance for service design as palliative care is increasingly introduced earlier in the patient's pathway.

CONCLUSION

Although the body of research is growing, management of fatigue caused by non-malignant conditions remains poorly evidenced, making comprehensive recommendations for these patient groups even more challenging.

Cardiopulmonary and Muscular Interactions: Potential Implications for Exercise (In)tolerance in Symptomatic Smokers Without Chronic Obstructive Pulmonary Disease

Smoking and physical inactivity are important preventable causes of disability and early death worldwide. Reduced exercise tolerance has been described in smokers, even in those who do not fulfill the extant physiological criteria for chronic obstructive pulmonary disease (COPD) and are not particularly sedentary. In this context, it is widely accepted that exercise capacity depends on complex cardio-pulmonary interactions which support oxygen (O₂) delivery to muscle mitochondria. Although peripheral muscular factors, O₂ transport disturbances (including the effects of increased carboxyhemoglobin) and autonomic nervous system unbalance have been emphasized, other derangements have been more recently described, including early microscopic emphysema, pulmonary microvascular disease, ventilatory and gas exchange inefficiency, and left ventricular diastolic dysfunction. Using an integrative physiological approach, the present review summarizes the recent advances in knowledge on the effects of smoking on the lung-heart-muscle axis under the stress of exercise. Special attention is given to the mechanisms connecting physiological abnormalities such as early cardio-pulmonary derangements, inadequate oxygen delivery and utilization, and generalized bioenergetic disturbances at the muscular level with the negative sensations (sense of heightened muscle effort and breathlessness) that may decrease the tolerance of smokers to physical exercise. A deeper understanding of the systemic effects of smoking in subjects who did not (yet) show evidences of COPD and ischemic heart disease - two devastating smoking related diseases - might prove instrumental to fight their ever-growing burden.

Influence of cognitive load on the dynamics of neurophysiological adjustments during fatiguing exercise

We aimed to determine the neurophysiological mechanisms associated with reduced endurance performance during cognitive-motor dual task at different levels of cognitive load, compared to a motor task alone. Eighteen healthy men performed isometric quadriceps contractions at 15% of maximal voluntary contraction (blocks of 170 s interspaced by neuromuscular evaluations) until exhaustion. This task was performed on three separate days: (a) in the absence of concomitant cognitive task, (b) with concomitant 1-back task, and (c) with concomitant 2-back task. Autonomic nervous system activity, perceived exertion, and cognitive performance were continuously monitored. Peripheral and central determinants of neuromuscular function were assessed at rest, between each block, and at task failure using femoral nerve stimulation. Endurance time was shorter during 2-back (982 ± 545 s) and 1-back (1,128 ± 592 s) conditions, compared with control (1,306 ± 836 s). Voluntary activation level was lower in 2-back (87.1%; p < 0.001) and 1-back (88.6%; p = 0.04) conditions compared to control (91.2%) at isotime (100% of the shortest test duration). Sympathetic activity showed a greater increase in 2-back condition compared to control. Perceived muscular exertion was higher during 2-back than during control. Cognitive performance decreased similarly with time during both cognitive-motor dual task but was always lower during 2-back condition. Motor performance is reduced when adding a concomitant demanding memory task to a prolonged isometric exercise. This can be explained by the interaction of various psychological and neurophysiological factors including higher perceived exertion, greater perturbations of autonomic nervous system activity, and cerebral impairments leading to earlier onset of central fatigue.

The Effect of Anodal Transcranial Direct Current Stimulation Over Left and Right Temporal Cortex on the Cardiovascular Response: A Comparative Study

Background: Stimulation of the right and left anterior insular cortex, increases and decreases the cardiovascular response respectively, thus indicating the brain’s lateralization of the neural control of circulation. Previous experiments have demonstrated that transcranial direct current stimulation (tDCS) modulates the autonomic cardiovascular control when applied over the temporal cortex. Given the importance of neural control for a normal hemodynamic response, and the potential for the use of tDCS in the treatment of cardiovascular diseases, this study investigated whether tDCS was capable of modulating autonomic regulation.

Methods: Cardiovascular response was monitored during a post-exercise muscle ischemia (PEMI) test, which is well-documented to increase sympathetic drive. A group of 12 healthy participants performed a PEMI test in a control (Control), sham (Sham) and two different experimental sessions where the anodal electrode was applied over the left temporal cortex and right temporal cortex with the cathodal electrode placed over the contralateral supraorbital area. Stimulation lasted 20 min at 2 mA. The hemodynamic profile was measured during a PEMI test. The cardiovascular parameters were continuously measured with a transthoracic bio-impedance device both during the PEMI test and during tDCS.

Results: None of the subjects presented any side effects during or after tDCS stimulation. A consistent cardiovascular response during PEMI test was observed in all conditions. Statistical analysis did not find any significant interaction and any significant main effect of condition on cardiovascular parameters (all ps > 0.316) after tDCS. No statistical differences regarding the hemodynamic responses were found between conditions and time during tDCS stimulation (p > 0.05).

Discussion: This is the first study comparing the cardiovascular response after tDCS stimulation of left and right TC both during exercise and at rest. The results of the current study suggest that anodal tDCS of the left and right TC does not affect functional cardiovascular response during exercise PEMI test and during tDCS. In light of the present and previous findings, the effect of tDCS on the cardiovascular response remains inconclusive.