Outcome
Type |
Measure |
Description |
Time frame |
Safety issue |
Primary |
Dyspnea BORG category ratio 10 scale (scores from 1 to 10; higher score = worse outcome = more dyspnea) |
Difference in dyspnea intensity perception on a 10-point Borg scale at comparable time points during constant work rate cycling exercise pre-post intervention between groups. |
pre-post 6 months intervention |
|
Secondary |
Respiratory muscle function |
Pi,max will be recorded using the technique proposed by Black and Hyatt. Pes,max, Pgas,max, and Pdi,max values will be obtained during maximal sniff and cough maneuvers.Twitch Pdi will also be measured after uni- and bilateral magnetic phrenic nerve stimulation. Inspiratory muscle endurance will be tested with a protocol that we have recently established. |
pre-post 6 months intervention and during every supervised IMT session in the hospital |
|
Secondary |
Phrenic nerve conduction |
Magnetic stimulation of the phrenic nerve in the neck in combination with diaphragmatic surface electromyography will be carried out to characterize phrenic nerve conduction. |
pre-post 6 months intervention |
|
Secondary |
Maximal end endurance exercise capacity |
A constant work rate (CWR) cycling test will be performed at 75% of the peak work rate achieved during a maximal incremental cardiopulmonary exercise test (CPET) to assess all main outcomes. CPET will be conducted on an electronically-braked cycle ergometer (Ergoline 800s; SensorMedics, Yorba Linda, CA) with detailed metabolic and cardiopulmonary measurements (SensorMedics Vs229d). On visit three (following IMT) two CWR tests will be performed. One until symptom limitation (tlim) and another until tlim of visit 2 to assess locomotor muscle fatigue at isotime as previously described by Amann et al. Subjects will rate intensity of breathing discomfort (dyspnea), unpleasantness of breathing, breathing-related anxiety, and leg discomfort, using the modified 10-point Borg scale. Qualitative descriptors of dyspnea will be collected at end-exercise. |
pre-post 6 months intervention |
|
Secondary |
Respiratory effort and neural respiratory drive to the diaphragm |
Pes, Pgas, Pdi and diaphragm electromyography (EMGdi) will be recorded continuously during cycle exercise using a multipair esophageal electrode catheter system. Surface EMG recordings of scalene and intercostal muscles will be performed according to a technique described by Duiverman et al. |
pre-post 6 months intervention |
|
Secondary |
Neural respiratory drive to breathing muscles |
Surface EMG recordings of scalene and intercostal muscles will be performed according to a technique described by Duiverman et al. |
pre-post 6 months intervention |
|
Secondary |
Pulmonary function (sitting and supine position) |
Spirometry and whole body plethysmography will be performed according to the European Respiratory Society guidelines for pulmonary function testing (Vs62j body plethysmograph, SensorMedics, Yorba Linda, CA). (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) and RV (L) will be registered. |
pre-post 6 months intervention and during every supervised IMT session in the hospital |
|
Secondary |
Severity of dyspnea pre intervention |
Assessed with Baseline throughout three categories: functional impairment, magnitude of task and magnitude of effort. A patient is asked open-ended questions regarding the symptoms. Following specific criteria, the observer is able to grade the degree of impairment (ranged 0-4) related to dyspnea for all three components. The range for the total score is 0-12. Lower score indicates a worse outcome. |
pre-post 6 months intervention |
|
Secondary |
Change in Severity of dyspnea post intervention |
Assessed with Transition Dyspnea Index (TDI) to assess changes over time. Patients report a slight, moderate or marked change, worse or better in comparison with BDI. A sum of the scores ranges between -9 and +9 where 0 indicates no change compared to baseline, a higher positive result indicates worsening of the condition and a lower negative result bigger improvement. |
pre-post 6 months intervention |
|
Secondary |
Dyspnea during daily life |
Clinical grade of breathlessness is assessed on 5 point (1 to 5) Medical Research Council Dyspnea Scale. Higher score means more dyspnea and a worse outcome. |
pre-post 6 months of intervention |
|
Secondary |
Postural control |
The participants will be asked to stand upright on a force plate. Displacements of the center of pressure (CoP) in anterior-posterior direction will be estimated from raw force plate data using the equation: CoP = Mx/Fz. Root mean square values of the CoP displacements will be used for the analysis of postural stability measures |
pre-post 6 months intervention |
|
Secondary |
Low back pain |
Disability related to low back pain will be evaluated using the Oswestry Disability Index, version 2 (adapted Dutch version) (ODI-2). A patient scores the impact of LBP on his functional ability in 10 domains of activities in daily life where each domain or item consists of 6 statements (scored 0-5). The total score is a sum ranging from 0 to 100 where higher score indicates a worse outcome (i.e. higher disability). |
pre-post 6 months intervention |
|