Effects of Lumbar Transcutaneous Electrical Nerve Stimulation on Exercise Performance in Patients With Chronic Obstructive Pulmonary Disease

Study Overview
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Brief Summary
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Chronic obstructive pulmonary disease is a leading cause of morbidity and mortality worldwide. Pulmonary rehabilitation effectively improves outcomes in patients with chronic respiratory disease. There is a link between training intensity and physiological improvements following pulmonary rehabilitation. However, high intensity training is not sustainable for every patients. Therefore, actual strategies for pulmonary rehabilitation aimed at decreasing dyspnea to improve muscle work. Electrical muscle stimulation is widely used during rehabilitation to promote muscle function recovery. Transcutaneous electrical nerve stimulation was recently used to relief dyspnea and improve pulmonary function in patients with chronic respiratory disease. Moreover, spinal anesthesia with fentanyl has been shown to be effective in improving exercise tolerance in patients with chronic obstructive pulmonary disease (inhibiting group III and IV muscle afferents). As transcutaneous electrical muscle stimulation stimulates the same receptors in the spinal cord dorsal horn as fentanyl, it is hypothesized that it could also improve exercise capacity. Therefore, the aim of this study is to assess wether transcutaneous electrical stimulation (high or low frequency) is effective in improving exercise capacity in patients with severe to very severe chronic obstructive pulmonary disease.

Detailed Description
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Design : cross-over. Patients will perform three constant workload testing (CWT) on different days under three different conditions. The intervention during the tests will be randomly assigned (concealed allocation) : Sham transcutaneous electrical nerve stimulation ; High-frequency transcutaneous electrical nerve stimulation ; Low-frequency transcutaneous electrical nerve stimulation.

Official Title
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Effects of Lumbar Transcutaneous Electrical Nerve Stimulation on Exercise Performance in Patients With Chronic Obstructive Pulmonary Disease : A Pilot Study

Conditions
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Chronic Obstructive Pulmonary Disease

Intervention / Treatment
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* Other: High-frequency transcutaneous electrical nerve stimulation
* Other: Low-frequency transcutaneous electrical nerve stimulation
* Other: Sham transcutaneous electrical nerve stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 years; Chronic obstructive pulmonary disease Gold III-IV; Eligible for pulmonary rehabilitation; Never used electrical stimulation. Non-inclusion Criteria: Pregnant woman or likely to be; Patient under guardianship; History of epilepsy, heart pace-maker or defibrillator, inguinal or abdominal hernia; Recent lumbar surgery or skin lesion; Allergy to surface electrodes; Lumbar sensitivity impairment; Opiate treatment during the last 3 months. Exclusion Criteria: Acute exacerbation of chronic obstructive pulmonary disease

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Three constant workload testing will be performed on three different days. Every test will be carried out with a different condition : Sham transcutaneous electrical nerve stimulation; High-frequency transcutaneous electrical nerve stimulation; Low-frequency transcutaneous electrical nerve stimulation.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CWT with high-frequency electrical nerve stimulation<br>This study has a cross-over design. Patients will achieve CWT with either sham, high-frequency or low-frequency lumbar transcutaneous electrical nerve stimulation in a randomised order. | Other: High-frequency transcutaneous electrical nerve stimulation<br>* 4 self adhesive surface electrodes are positioned by pair at the L3-L4 level, laterally. Stimulation is setted at rest, 10min before constant workload testing. During this period, intensity is increased every 3minutes to the maximum tolerated by the patient (pain threshold). Thereafter, intensity is not increased anymore during the test. It is explained to the patient that he might or no experience the electrical stimulation sensation. Current characteristics : 100Hertz, 100ms, bidirectional. Constant workload testing : 60-70rpm ; 75% Wpic ; up to exhaustion or rpm < 60 during more than 10s.<br>|
| Experimental: CWT with low-frequency electrical nerve stimulation<br>This study has a cross-over design. Patients will achieve CWT with either sham, high-frequency or low-frequency lumbar transcutaneous electrical nerve stimulation in a randomised order. | Other: Low-frequency transcutaneous electrical nerve stimulation<br>* 4 self adhesive surface electrodes are positioned by pair at the L3-L4 level, laterally. Stimulation is setted at rest, 10min before constant workload testing. During this period, intensity is increased every 3minutes to the maximum tolerated by the patient (pain threshold). Thereafter, intensity is not increased anymore during the test. It is explained to the patient that he might or no experience the electrical stimulation sensation. Current characteristics : 4Hertz, 100ms, bidirectional. Constant workload testing : 60-70rpm ; 75% Wpic ; up to exhaustion or rpm < 60 during more than 10s.<br>|
| Experimental: CWT with sham electrical nerve stimulation<br>This study has a cross-over design. Patients will achieve CWT with either sham, high-frequency or low-frequency lumbar transcutaneous electrical nerve stimulation in a randomised order. | Other: Sham transcutaneous electrical nerve stimulation<br>* The procedure is the same as high-frequency transcutaneous electrical stimulation but intensity is progressively setted back to 1mA (over a 45sec period) after every increment so that constant workload testing is performed with 1mA.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of endurance time (Tlim, in second) during constant workload testing (CWT) under 3 conditions. | Patients will achieve 3 constant workload testing under 3 different conditions (sham lumbar transcutaneous electrical nerve stimulation, high-frequency lumbar electrical nerve stimulation and low-frequency lumbar transcutaneous electrical nerve stimulation). Endurance time (sec) will be recorded at the end of every test. Endurance time will be compared to assess how the condition will influence exercice performance. | The outcome will be measured after every CWT. Data will be continuously collected during the tests. The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dyspnea during CWT using modified Borg Scale (0-10). | The dyspnea will be assessed every 30sec during CWT. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be collected every 30s during tests | 
| Exhaustion during CWT using modified Borg Scale (0-10). | The exhaustion will be assessed every 30sec during CWT. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be collected every 30s during tests.] | 
| Heart rate (rpm) during CWT. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Blood pressure (mmHg) before and after every CWT. |  | The outcome will be assessed before and after every CWT. The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. | 
| Oxygen saturation (SpO2, %) during CWT. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| O2 consumption (VO2, mL/kg/min) during CWT. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Exercise ventilation (VE, L/min) during CWT. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Tidal Volume (Vt, L) during CWT. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Respiratory Rate (RR, rpm) during CWT. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Variation of total hemoglobin (THb) using near infra red spectroscopy. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Variation of total desoxy-hemoglobin (HHb) using near infra red spectroscopy. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Variation of total oxy-hemoglobin (HbO2) using near infra red spectroscopy. | Outcome will be continuously recorded. Results will be shown at Tlim (Tlim for the 3 tests) and iso time (defined as the Tlim or the shortest test). | The outcome will be measured during every CWT.The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected | 
| Intensity of electrical stimulation (mA) reached during every CWT. |  | The outcome will be measured after every CWT. The 3 CWT will be carried out in different days, separate from 1 day minimum for a total time frame of 2 weeks maximum. Data will be continuously collected |