Effects of Inspiratory Muscle Training on Shortness of Breath (Dyspnea) and Postural Control in Patients With COPD
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|ClinicalTrials.gov Identifier: NCT03240640|
Recruitment Status : Recruiting
First Posted : August 7, 2017
Last Update Posted : January 30, 2019
Shortness of breath (dyspnea) is an important symptom during physical exertion in patients with chronic obstructive pulmonary disease (COPD) and is related to respiratory muscle weakness. Dyspnea is a multidimensional sensation. The sensory perceptual domain (perceived dyspnea intensity) has been study extensively. The perception of respiratory distress (unpleasantness of dyspnea) has not received as much attention. Inspiratory muscle training (IMT) has been shown to improve inspiratory muscle function and reduce dyspnea intensity. Balance impairments increasing the risk of falling is another recognized problem in patients with COPD. Postural balance has been shown to be especially impaired in patients with COPD who have pronounced respiratory muscle weakness. Improvements in respiratory muscle function might improve balance control in patients. Respiratory Muscle Metaboreflex is known as respiratory muscle work during exercise reflexively induces sympathetically mediated vasoconstrictor activity, there by compromising blood flow and oxygen delivery to active limb and respiratory muscles.
Eight weeks of controlled IMT is hypothesized to reduce both intensity as well as unpleasntness domain of dyspnea perception, improve postural control and improves blood flow and oxygen delivery to limb muscles in patients with COPD who have pronounced respiratory muscle weakness.
|Condition or disease||Intervention/treatment||Phase|
|Copd Inspiratory Muscle Weakness||Procedure: Inspiratory Muscle Strength Training Procedure: Inspiratory Muscle Endurance Training||Not Applicable|
Show Detailed Description
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||24 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Double (Participant, Outcomes Assessor)|
|Official Title:||Effects of Inspiratory Muscle Training on Shortness of Breath (Dyspnea) and Postural Control in Patients With COPD|
|Actual Study Start Date :||February 1, 2017|
|Estimated Primary Completion Date :||December 31, 2019|
|Estimated Study Completion Date :||January 31, 2020|
Experimental: Inspiratory Muscle Strength Training
High intensity inspiratory muscle training
Procedure: Inspiratory Muscle Strength Training
IMT will be performed using a variable flow resistive loading device (POWERbreathe®KH1, HaB International Ltd., Southam, UK). The device is able to store training parameters of up to 40 sessions. Most training sessions during this RCT will be performed by patients at their homes without supervision. The intervention group (strength IMT) will perform two daily sessions of 30 breaths. Measurements of Pi,max will be performed every week and training loads will be increased continuously to maintain at least 40-50% of the actual Pi,max values. Each week, one training session will be performed under supervision. Training load will be increased during this session.
Sham Comparator: Inspiratory Muscle Endurance Training
Sham inspiratory muscle training at low intensity
Procedure: Inspiratory Muscle Endurance Training
IMT will be performed using a variable flow resistive loading device (POWERbreathe®KH1, HaB International Ltd., Southam, UK). The device is able to store training parameters of up to 40 sessions. Most training sessions during this RCT will be performed by patients at their homes without supervision. The sham group (endurance IMT) will perform three daily sessions of 30 breaths and will train at a constant inspiratory load of no more than 10% of their initial Pi,max. Each week, one training session will be performed under supervision.
- Dyspnea (Borg CR-10 scale) [ Time Frame: Change from Baseline in Borg CR-10 scale at 8 weeks ]
Dyspnea intensity perception on a 10-point Borg scale during constant work rate cycling exercise.
Numerical value reported for intensity of dyspnea (shortness of breath) ranging from 0 (no symptoms) to 10 (maximal symptoms)
- Center of pressure displacement [ Time Frame: Change from Baseline in center of pressure at 8 weeks ]Difference in center of pressure displacement on unstable support surface during a balance task after the intervention
- Maximal inspiratory pressure (Pi,max) [ Time Frame: Change from Baseline in Pi,max at 8 weeks ]Maximal voluntary inspiratory pressure will be recorded at the mouth to assess inspiratory muscle strength (pressure generating capacity). Measurements will be performed at functional residual capacity for inspiratory respiratory pressure (maximal inspiratory pressure; Pi,max ) using the technique proposed by Black and Hyatt. (Black LF, Hyatt RE. Maximal respiratory pressures: normal values and relationship to age and sex. Am Rev Respir Dis 1969;99:696-702.) An electronic pressure transducer will be used (MicroRPM; Micromedical, Kent, UK) to register pressures. Reference values published by Rochester and Arora will be used to define percentages of normal respiratory muscle pressures. (Rochester DF, Arora NS. Respiratory muscle failure. Med Clin North Am 1983;67:573-97.)
- Inspiratory Muscle Endurance during a constant load breathing task [ Time Frame: Change from Baseline in endurance time at 8 weeks ]To measure inspiratory muscle endurance patients will be asked to breathe against a submaximal inspiratory load provided by a flow resistive loading device (POWERbreathe®KH1, HaB International Ltd., Southam, UK) until task failure. An inspiratory load will be selected that allows patients to continue breathing against the resistance for 3-7 minutes (typically between 50-60% of the Pi,max). Breathing instructions for patients will be the same as during the training sessions. Number of breaths, average duty cycle (inspiratory time as a fraction of the total respiratory cycle), average load, average power, and total work will be registered during the test by the handheld loading device. After 8 weeks of IMT the test will be repeated against an identical load and improvements in endurance time (seconds) will be registered as the main outcome. Changes in breathing parameters will be also registered.
- Endurance capacity during a constant load cycling exercise test [ Time Frame: Change from Baseline in endurance cycling time at 8 weeks ]A constant work rate (CWR) cycling test will be perform at 75% of the peak work rate achieved during a maximal incremental cardiopulmonary exercise test (CPET). Time (minute) till symptom limit during a CWR cycling will be measured.
- Respiratory effort [ Time Frame: Change from Baseline in respiratory effort at 8 weeks ]Pes-Esophageal Pressure (cmH2O) and Pgas-Gastric Pressure (cmH20) will be recorded continuously using a multipair esophageal electrode catheter system to assess respiratory effort (Pi/Pi,max). Maximal sniff and cough maneuvers will be performed to obtain Pes,max, Pgas,max, and Pdi,max values. Pdi -Transdiaphragmatic Pressure (cmH2O) will be calculated by subtraction of Pes from Pga.
- Neural Respiratory Drive [ Time Frame: Change from Baseline in Neural Respiratory Drive at 8 weeks ]Measuring neural output in term of activation of respiratory muscles using a multipair esophageal electrode catheter system. EMGdi-Diaphragm electromyogram (volt), sEMG-Transcutaneous electromyography (volt) of the scalene and intercostal muscles will be derived by using technique described by Duiverman et al. The result will be presented in the percentage of maximum activation of each respiratory muscle (%EMGmax)
- Ventilatory Muscle Recruitment (VMR) [ Time Frame: Change from Baseline in Ventilatory Muscle Recruitment at 8 weeks ]The ventilatory muscle recruitment (VMR) will be determined as the slope of the line between points of zero flow at end-expiration and end-inspiration for the Pga-Pes Plots; Increasing contribution of the diaphragm is represented by more negative slopes, while less negative slopes represent increasing contribution of inspiratory.
- Respiratory and locomotor muscle perfusion [ Time Frame: Change from Baseline in respiratory and locomotor muscle blood flow at 8 weeks ]Near infrared spectroscopy (NIRS) in combination with indocyanine green tracer (ICG) (NIRS-ICG method) will be used to simultaneously assess blood flow index (BFI) in both respiratory and locomotor muscle. Specifically, for the respiratory muscles BFI will be measured by recording the tissue ICG concentration over time (i.e., ICG concentration curve) by NIRS and will be expressed in nM/s (nanomoles per second) units. The same procedure will be applied for the locomotor muscle and BFI will also expressed as nM/s (nanomoles per second) units.
- Locomotor muscle fatigue (Quadriceps twitch forces) [ Time Frame: Change from Baseline in quadriceps twitch forces at 8 weeks ]Quadriceps twitch forces will be measured using transcutaneous magnetic twitch stimulation of the femoral nerve. Comparing the quadriceps twitch forces before and after exercise is a representation of locomotors muscle fatigue.
- Pulmonary Function [ Time Frame: Change from Baseline in Pulmonary Function parameters at 8 weeks ]Pulmonary function Spirometry and whole body plethysmography will be performed according to the European Respiratory Society guidelines for pulmonary function testing (Vmax Autobox, Sensor Medics, Bilthoven, the Netherlands). (Quanjer PH, Tammeling GJ, Cotes JE, et al. Lung volumes and forced ventilatory flows. Report Working Party Standardization of Lung Function Tests, European Community for Steel and Coal. Official Statement of the European Respiratory Society. Eur Respir J Suppl 1993;16:5-40.) Changes in FEV1 (L), FVC (L), FRC (L), RV (L), IC (L) and peak inspiratory flow (L/s) will be registered.
- Daily Physical Activity [ Time Frame: Change in daily steps and time in moderate to vigorous daily physical activity from Baseline at 8 weeks ]Assessed with the Actigraph and Dynaport MoveMonitor monitor. Step per day (steps) and time (hours) of moderate to vigorous daily physical activity will be measured.
- Dyspnea intensity (Borg CR-10 scale) [ Time Frame: Change from Baseline in Borg CR-10 scale at 8 weeks ]Rating of dyspnea intensity (Borg CR-10 scale) during standardized loaded breathing tasks with occlusion events.
- Dyspnea unpleasantness (Borg CR-10 scale) [ Time Frame: Change from Baseline in Borg CR-10 scale at 8 weeks ]Rating of dyspnea unpleasantness (Borg CR-10 scale) during standardized loaded breathing tasks with occlusion events.
- Respiratory-related evoked potential (RREPs) [ Time Frame: Change from Baseline in RREPs at 8 weeks ]Respiratory-related evoked potential (RREPs) measured by means of EEG during condition of resistive load induced dyspnea and unloaded breathing.
- Evoked potential elicited by the geometric figures [ Time Frame: Change from Baseline in Evoked potential at 8 weeks ]Evoked potential elicited by the geometric figures during baseline and dyspnea condition
- Stress level [ Time Frame: Change from Baseline in stress level at 8 weeks ]Stress level before, during and after test intermittent dyspnea challenges will be measured using distress thermometer, rating on the scale 1 to 10.
- Salivary cortisol levels [ Time Frame: Change from Baseline in salivary cortisol levels at 8 weeks ]Salivary cortisol levels (nmol/l) before, during and after test intermittent dyspnea challenges was collected. The level between >7 and <17 nmol/l considers standard cortisol levels.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03240640
|Contact: Daniel Langer, Phdfirstname.lastname@example.org|
|University Hospital Leuven||Recruiting|
|Leuven, Belgium, 3000|
|Contact: Daniel Langer, PT, PhD 0032-16-330192 email@example.com|
|Principal Investigator: Rik Gosselink, PT, PhD|
|Principal Investigator:||Rik Gosselink, PhD||Vicerector of Student Affairs KU Leuven|