Surface Respiratory Electromyography Measurements During Treadmill Exercise in Stable Patients With COPD
Condition: Respiratory Disease
MeSH terms: Respiratory Tract Diseases; Respiration Disorders
Study type: Interventional

Summary: 
      To evaluate the compatibility and correlation between noninvasive surface respiratory
      electromyography and invasive transesophageal diaphragmatic electromyography measurements, as
      facilitating indicators of neural respiratory drive evaluation during treadmill exercise.
      Transesophageal diaphragmatic EMG (EMGdi,es) and surface inspiratory EMG, including surface
      diaphragmatic EMG (EMGdi,sur), surface parasternal intercostal muscle EMG (EMGpara) and
      surface sternocleidomastoid EMG (EMGsc) were detected simultaneously during increasing
      capacity exercise in stable patients with COPD. EMGdi,es, EMGdi,sur, EMGpara and EMGsc was
      quantified using root mean square (RMS), which represent as RMSdi,es, RMSdi,sur, RMSpara and
      RMSsc.
    

Detailed description: 
      Subjects This self-matching clinical trial included twenty patients with COPD (age range,
      40-80 years) treated at outpatient respiratory medicine departments at the First Affiliated
      Hospital of Guangzhou Medical University between July 2016 and December 2016. The diagnosis
      of COPD in all participants were measured using the pulmonary spirometry, according to the
      Global Initiative for Chronic Obstructive Lung Disease (GOLD).1 Inclusion criteria: 1) post
      bronchodilator forced expiratory volume in 1 s [FEV1]/forced vital capacity [FVC] ,70% and
      FEV1 ,50% of the predicted value); 2) bronchial dilation test (BDT) negative. Exclusion
      criteria: 1) acute exacerbation in the previous 4 weeks; 2) use of oral corticosteroids
      within 4 weeks; and 3) smoking more than 10 cigarettes daily; (4) history of other
      respiratory, cardiovascular, neuromuscular, and musculoskeletal diseases that could interfere
      with the exercise performance and inspiratory muscle activities.

      Study design This study has been reviewed and published on the ClinicalTrials.gov public site
      (identifier: NCT03017300, Clinical trial date of registration: March 29, 2017). The study
      protocol was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou
      Medical University. Informed consent was obtained from COPD patients before participation in
      this study. To ensure the rights of all participants were protected, the researchers strictly
      adhered to the Declaration of Helsinki and the ethical principles in designing and conducting
      clinical research.

      Measurements of transesophageal diaphragmatic EMG (EMGdi,es) EMGdi,es is the classic
      representative index describing activity of diaphragmatic myoelectric signals, the electrical
      manifestations of the excitation process elicited by action potentials propagating along
      muscle fiber membranes. The EMG signal is detected with multiple electrodes and then
      amplified, filtered, and displayed on a screen or digitized to facilitate further analysis.
      Electromyography of respiratory muscles can be used to assess the level and pattern of their
      activation so as to detect and diagnose neuromuscular pathology and, when coupled with tests
      of mechanical function, to assess the efficacy of the muscle's contractile function. Neural
      respiratory drive, expressed as EMGdi, was measured using a multipair esophageal electrode
      consisting of nine consecutive coils composed of five electrode pairs positioned in the
      esophagus and traversing the cardia. EMGdi signals acquired with digital sampling at 2 kHz
      were bandpass filtered (10 Hz-3 kHz) and amplified. Peak RMS per respiratory cycle was
      calculated and averaged over 1 min. RMS of the EMGdi signal is thequantification of the total
      EMGdi power. Theoretically, the RMS of the EMGdi reflects the force output from the brainstem
      respiratory centre to the peripheral respiratory muscles and also reflect the sensation of
      dyspnea.

      Measurements of surface inspiratory EMG EMG electrodes The electrical activity of the surface
      inspiratory EMG was derived transcutaneously from pairs of single disposable electrodes
      (Neotrode, Conmed Corporation, New York, USA). For the commonor ground electrode the same
      disposable electrode was used. Electrical activity of the sternocleidomastoidmuscles and
      Intercostals muscles were derived transcutaneously from reusablebipolar electrodes formed by
      two narrow rim electrodes housings, each containing a 4mm Ag-AgCl sintered electrode pallet
      (InVivo Metrics, Healdsburg, USA), interconnected with a plastic clip (homemade UMCG,
      Groningen, The Netherlands) at a distance of14mm. After filling the electrode cavity with
      electrode gelthe assembly was fixed to the skin by means of double sided adhesives. All EMG
      signals detected by electrodes were convey to connected to the biological signal acquisition
      and analysis system (Powerlab 16/35; ADInstruments) by shielded low noise cables.

      Electrode placement Surface diaphragmatic EMG (EMGdi,sur): The surface detecting electrode
      couple were separately placed at the intersection point of the sixth and eight intercostal
      space and anterior axillary line, at a distance of 5 cm.10 Surface parasternal EMG (EMGpara):
      The surface detecting electrodes were placed bilaterally in the second intercostal space,
      about 3 cm parasternal, a reference ground electrode was placed atthe sternum sternal angle.

      Surface sternocleidomastoid EMG (EMGsc): Surface detecting electrode were placed on the 1/3
      and 2/3 of overall length of sternocleidomastoid, a reference ground electrode was placed at
      the suprasternal fossa.

      Exercise testing All subjects performed a maximal incremental cycle ergometry test in a
      sitting posture, in order to minimize the effects of muscle activity necessary for body
      stabilization (Ergoselect 200 K; Cosmed, Rome, Italy). Furthermore, to minimize muscle
      activity for head positioning, the subjects were instructed to look straight ahead during the
      measurements. The test consisted of a steady-state resting period of 3 min followed by 1 min
      of unloaded pedaling at 60 cycles/min for each individual; the exercise load was increased by
      10 W each min until the test had to be stopped because symptoms prevented further exercise.
      After test results were recorded, EMGdi,es and each surface inspiratory EMG of maximal
      exercise capacity were analysed.
    

Intervention name(s): Exercise testing
Intervention type(s): Diagnostic Test
Intervention description(s): The test consisted of a steady-state resting period of 3 min followed by 1 min of unloaded pedaling at 60 cycles/min for each individual; the exercise load was increased by 10 W each min until the test had to be stopped because symptoms prevented further exercise. After test results were recorded, EMGdi,es and each surface inspiratory EMG of maximal exercise capacity were analysed.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: neural respiratory drive; transesophageal diaphragmatic EMG; surface diaphragmatic EMG; surface sternocleidomastoid EMG; surface parasternal intercostal muscle EMG