Fatigue and Physical Performance During Pulmonary Rehabilitation

Study Overview
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Brief Summary
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Patients with COPD benefit from pulmonary rehabilitation (PR), but a ceiling effect of performance (ie. absence of additional exercise tolerance increase) is observed in 80% of patients from only 20 sessions. An imbalance between intensity, duration and frequency of PR sessions, leading to fatigue development in the course of the PR, could explain this ceiling effect. However, previous studies having evaluated the impact of a PR program on fatigue scores reported either a decrease or no changing, but never an increase. To date, no study has evaluated intermediate variations of fatigue score during a PR program, but were limited to a pre-post PR assessment. Therefore, fatigue fluctuations during PR are unknown. Furthermore, most studies had only unidimensional fatigue assessment. Since fatigue is a multifactorial and a multidimensional process, it cannot be accurately estimated through a unique assessment. Given that most of COPD patients do not increase their exercise tolerance from 20 PR sessions, the investigators hypothesize a significant increase of multidimensional fatigue score between the 1st and the 20th PR session during an inpatient rehabilitation program lasting 4 weeks (40 sessions).

Detailed Description
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Exercise tolerance is an important predictor of health status in patients with chronic obstructive pulmonary disease (COPD). A reduced 6-min walking distance is associated with an increased mortality risk in these patients. Pulmonary rehabilitation (PR) is one of the most efficient strategy to counterac this effect. Patients improving their exercise tolerance after a PR program have a reduced mortality risk. However, exercise tolerance improvement is not systematic after PR, since up to 1/3 of patients do not respond to the intervention. In addition, PR's effects are limited, with a ceiling effect of performance observed in 80% of patients from 20 sessions. Fatigue could be one candidate to explain the ceiling effect of physical performance during PR. From a theoritical point of view, national and international guidelines on PR have continuously broadened PR interventions for the last 20 years, by progressively introducing in addition to endurance training, resistance training of the lower and then the upper limbs, electrical stimulation, stretching, respiratory muscle training... From a practical point of view, several patients complain of fatigue during PR. However, previous studies having evaluated the impact of a PR program on fatigue scores reported either a decrease or no changing, but never an increase. To date, no study has evaluated intermediate variations of fatigue score during a PR program, but were limited to a pre-post PR assessment. Therefore, fatigue fluctuations during PR are unknown. Furthermore, most studies had only unidimensional fatigue assessment. Since fatigue is a multifactorial and a multidimensional process, it cannot be accurately estimated through a unique assessment. Mutdimensional questionnaires and complementary indicators such as heart rate variability or visuomotor reaction time could be introduced. Given that most of COPD patients do not increase their exercise tolerance from 20 PR sessions, the investigators hypothesize a significant increase of multidimensional fatigue score between the 1st and the 20th PR session during an inpatient rehabilitation program lasting 4 weeks (40 sessions).

Official Title
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Impact of Fatigue on Physical Performance During a Pulmonary Rehabilitation Program in Patients With COPD

Conditions
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Chronic Obstructive Pulmonary Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients admited for a 4-weeks inpatient pulmonary rehabilitation program With a confirmed diagnosis of COPD Exclusion Criteria: Severe or unstable heart disease Orthopedic, neurologic or psychatric comorbities Recent exacerbation (<4 weeks)

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Inpatient pulmonary rehabilitation<br>Multidisciplinary inpatient pulmonary rehabilitation program lasting 4 weeks (40 sessions, 2 sessions per day, 5 days per week). | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Multidimensional fatigue score | Change in total fatigue score measured with the MFI-20 questionnaire | Baseline (T0), 1st week (T1), 2nd week (T2), 3rd week (T3) and 4th week (T4) of the PR program | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6-min walking distance | Change in walking distance during a 6-min period over a corridor of 30m length | Baseline (T0), 1st week (T1), 2nd week (T2), 3rd week (T3) and 4th week (T4) of the PR program | 
| Heart rate variability | Change in SDNN and RMSSD indices of RR intervals during a 5-min resting period and at exercise during a 6-min walking test | Baseline (T0), 1st week (T1), 2nd week (T2), 3rd week (T3) and 4th week (T4) of the PR program | 
| Visuomotor reaction time | Change in the mean of 15 reaction time in response to visual stimuli | Baseline (T0), 1st week (T1), 2nd week (T2), 3rd week (T3) and 4th week (T4) of the PR program | 
| Correlation between fatigue and physical performance | Change in the strength of the correlation between indicators of fatigue (muldimensional score, heart rate variability, visuomotor reaction time) and 6-min walking distance | Baseline (T0), 1st week (T1), 2nd week (T2), 3rd week (T3) and 4th week (T4) of the PR program |