Diagnosis And Monitoring Of Cardio-Respiratory Disorders: COPD Diagnosis And Therapy Techniques

COPD Diagnosis and Treatment from the Medical View

COPD (Chronic Obstructive Pulmonary Disease) the diagnosis is based on spirometry intervention that effectively evaluates the level of airflow obstruction. The ratio of forced expiratory volume in one second and forced vital capacity (i.e. FEV1/FVC) assists in diagnosing COPD severity. FER (forced expiratory ratio) value of less than 0.7 (following bronchodilator administration) is regarded as a cut-off point for COPD (Johns, Walters and Walters, 2014). Similarly, the FEV1 value greater than 80% is indicative of mild COPD. Similarly, 50-80%, 30-49%, and less than 30% FEV1 values predict moderate, severe, and very severe forms of COPD. However, the ancillary diagnostic testing for COPD is based on the identification of clinical symptoms (including a chronic cough, dyspnea, and expectoration), history, physical examination, chest X-ray, bronchodilator reversibility testing and FEV1 normalization assessment (Burkhardt and Pankow, 2014). The assessment of transdiaphragmatic pressure through EMG (electromyographic) analysis substantially assists in evaluating the respiratory incapacity of the COPD patients (Sarlabous et al., 2017). Similarly, mechanomyographic assessment helps in mechanical muscle potential of the COPD suspects. Pharmacotherapeutic treatment of COPD is based on the administration of bronchodilators, glucocorticoids, vasodilators, antitussives, immunoregulators, antioxidants, mucolytic agents, α1-antitrypsin augmentation therapy, antibiotics, and vaccines. The symptomatic treatment of COPD is based on the administration of long and short-acting drugs including theophylline, anticholinergics, and selective β2-adrenergic agonists (Montuschi, 2006). The treatment of COPD exacerbations warrants the administration of glucocorticoids along with other combination drugs.      

COPD therapy techniques for treating the patients affected with severe airflow obstruction include the breathing intervention, biofeedback, distraction therapy, guided imagery, progressive muscle relaxation, acupuncture, and other relaxation techniques (Volpato et al., 2015). Furthermore, pulmonary rehabilitation includes significant techniques attributing to respiratory muscle training, breathing therapy, smoking cessation, support, psychosocial support, nutrition counseling, behavioral training, patient education, exercise training, and pharmacological treatment optimization. These techniques enhance the survival rate, muscle functioning, health-related quality of life, and exercise capacity of COPD patients (Leupoldt et al., 2012). These interventions also assist in controlling depression, anxiety, and breathlessness perception of the target population to a considerable extent. The progressive muscle relaxation technique requires the enhancement of tension at the targeted body part followed by relaxation after an interval of five seconds. This process requires repetition for different muscle groups with a gap of 15 seconds. However, conventional pharmacotherapy inhaler techniques are based on the recommended use of inhaler devices to administer the appropriate dose of the selected drug across the respiratory system (Nguyen and Nguyen, 2018). Treatment of severe COPD is also based on oxygen therapy that assists in enhancing the quality of life and survival rate of the affected patients. Oxygen therapy substantially assists in minimizing exertional dyspnoea in COPD patients (Barnes and Stockley, 2005). Antibiotic administration to the COPD patients is required to control bacteria associated virus-based COPD exacerbations. The administration of oral antibiotics impacts bacterial colonization across the lower respiratory passage. The long-term antibiotic use by COPD patients effectively stabilizes the respiratory system and controls exacerbation episodes for an extended duration. Smoking cessation intervention includes the nicotine addiction therapy that attempts to improve the long-term quit rate of the COPD patients (Barnes and Stockley, 2005).         

COPD Therapy Techniques from the Medical View

Methodology

The study by (Sarlabous et al., 2017) utilized capacitive accelerometers to record the respiratory muscle mechanomyogram (MMG) signal. The placement of accelerometers over right anterior axillary lines, 7-8 intercostal space, and chest surface assisted in recording the mechanical vibrations of the diaphragm muscle. A 12-bit analog-to-digital converter was used to register the respiratory muscle MMG signal as well as inspiratory mouth pressure. A zero-phase fourth-order Butterworth filter was utilized to filter the MMG recordings of the frequency of 5-25Hz in the context of surpassing the respiration-based chest wall’s reduced frequency movement.

The selected subjects were asked to sit in an upright manner while acquiring a comfortable posture. T tube was connected to the mouthpiece for breathing facilitation. The inspiratory mechanical activation was recorded during the effortless breathing for the 1-minute duration. The IVE (incremental ventilatory effort) protocol was initiated with the objective of progressively enhancing the intensity and rhythm of the breathing pattern of the study subjects. Subsequently, the subjects were instructed to resume the shallow breathing pattern while reducing the breathing intensity and rhythm. This technique assisted in recording the inspiratory pressure of subjects in accordance with their total airflow pattern. The protocol lasted for 2-6 minutes while three-times replicating the technique for every study subject. 

The study engaged seven healthy subjects and thirteen patients affected by COPD. Healthy subjects included four males and three female individuals. However, diseased subjects included eleven male and two female patients.

MLZ (Multistate Lempel-Ziv) index was utilized to record the inspiratory muscles’ mechanical strength. The assessment of non-occluded tidal volume-based peak inspiratory mouth pressure helped in tracking the inspiratory muscles’ mechanical outcome during a complete respiratory cycle. This assisted in evaluating the overall distensibility and activity of the respiratory muscle. The MMG indices/peak inspiratory mouth pressure’s median value recording assisted in evaluating the mechanical activation pattern and inspiratory muscle effort of the selected subjects. The MMG-based inspiratory muscle activity was eventually compared with the inspiratory muscle potential obtained through the conventional RMS (root mean square) method. Pearson correlation coefficient and Wilcoxon signed-rank test were used to comparatively analyze the inspiratory muscle capacity of healthy groups and COPD patients.        

The study outcomes revealed the elevated value of mean respiratory frequency in COPD patients as compared to the healthy subjects. Ventilation level enhancement significantly increased the MMG-RMS, MMG-MLZ, and peak inspiratory mouth pressures in COPD groups as compared to the healthy subjects. The mean and peak tidal volume and inspiratory mouth pressure assisted in identifying the inspiration-based muscle effort, respiratory components, and respiratory system compliance of the study groups. The assessment of synergistic respiratory muscle action was undertaken through the evaluation of inspiratory mouth pressure of the study candidates. The study revealed an inverse relationship between respiratory muscle activation and COPD severity.  

Study – 1

The study by (Torres et al., 2010) instrumented the subjects with the objective of acquiring the right and left hemidiaphragm mechanomyometric signals (MMGr and MMGl) along with the (IP) inspiratory pressure. The pressure transducer was utilized and placed across the subjects’ breathing tube for the IP assessment. The thoracic cage was used to place Kistler 8312B2 capacitive accelerometers in the context of retrieving MMGr and MMGl levels. Bilateral hemidiaphragm MMG signals were serially obtained through sensors’ placement across the 7-8 intercostal regions of the bilateral anterior axillary lines. The amplification, digitization, and decimation of signals were undertaken at the sampling frequencies of 4KHz and 200Hz respectively.     

The subjects were instructed for mouth breathing in a sitting position. The nose clip, tube, and mouthpiece were utilized to facilitate the mouth breathing process. The air outlet through exhalation was effectively maintained in the absence of obstruction. The blockage in the inspiration tube was maintained through small weights. The inhalation process required inspiratory effort by the subjects in the context of lifting the obstruction. The quiet respiration process, in the beginning, was performed in the absence of load. The inspiratory load addition (pertaining to 10cm H2O) was performed with an interval of two minutes after the acquisition of an intense breathing pattern. The test was terminated after the termination of inspiratory load bearing capacity (due to respiratory muscle fatigue) of the concerned subjects. The subjects were instructed to maintain the breathing activity intensity and rhythm throughout the respiratory protocol. The inspiratory pressure elevation was maintained through the gradual elevation of the respiratory load. IP-max (i.e. maximum inspiratory pressure) was evaluated in each respiratory cycle.   

The sampling was based on the selection of 6-patients affected by COPD.

Pearson coefficient was used to correlate IP-max with f-max (maximum frequency), LZM (Multistate Lempel-Ziv coefficient), H (Rényi entropy), and RMS (root mean square) (i.e. MMG attributes).

The elevation in incremental pressure resulted in a reduction of MMG signal frequency. Conversely, MMG amplitude parameters exhibited a substantial elevation in compliance with the enhancement of incremental pressure. The entropy parameter was found to be superior to all other attributes. The findings indicated the relationship between pulmonary function test attributes, incremental pressure, and MMG parameters. The inspiratory pressure elevation substantially deteriorated the respiratory muscle MMG (mechanomyogram) the frequency of the selected subjects. In summary, MMG signals were found to be effective in tracking the muscle capacity and respiratory effort of the COPD patients.

Methodology

The sternomastoid muscle was targeted for EMG (electromyography) through the utilization of a portable EMG machine (Kanwade and Bairagi, 2016). The tedious and central muscle regions were selected for electrode placement. The respiratory load was constantly provided before data collection. The electrode centers were separated apart with 1-2cm distance.

Patients’ demographic and spirometry data were evaluated for comparison with the standard system. EMG assessment was performed to evaluate the number of peaks/turns, mean rectified voltage, root mean square value, peak-to-peak value, and linear envelope in accordance with the prespecified frequency and time domains. Lineal envelop indicated myoelectric activity and contraction pattern of the sternomastoid muscle that required retrieval through the utilization of 20Hz low pass filter and full wave rectifier. Root mean square method was used to further evaluate the muscle contraction pattern and associated behavior of the motor unit. The integration value of the sternomastoid muscle reciprocated the action potential frequency and amplitude duration. The enhancement of EMG zero-crossing value for reduced activity level Indicated increased muscle function. Spike counting method indicated muscle activity at the reduced level of force. In summary, EMG signals the physiological events of the selected sternomastoid muscle.

The researchers selected four females and six male COPD subjects pertaining to the age group of 56-20 years for their EMG evaluation of the sternomastoid muscle.  

Data analysis for performed by correlation coefficient to evaluate the relationship between sternomastoid muscle activity, respiratory effort, and forced an expiratory volume of the selected candidates.

The results indicated a reciprocal relationship between sternomastoid muscle activity and EMG peak voltage. Furthermore, the activity of sternomastoid muscle was based on respiratory effort undertaken after a reported reduction in forced expiratory volume. The study outcomes also revealed a significant relationship between EMG peak voltage and COPD level of the selected subjects. A significant relationship was recorded between COPD, EMG frequency domain peaks, and RMS voltage. The forced vital capacity of the COPD patients reciprocated with their body mass indices. Enhanced sternomastoid muscle activity indicated COPD severity elevation of the selected study subjects. In summary, EMG proved to be a significant diagnostic utility to effectively record the COPD severity of the selected patients.    

References

Barnes, P.J. and Stockley, R.A. (2005) ‘COPD: current therapeutic interventions and future approaches’, ERJ, pp. 1084-1106, Available: https://erj.ersjournals.com/content/25/6/1084.

Burkhardt, R. and Pankow, W. (2014) ‘The Diagnosis of Chronic Obstructive Pulmonary Disease’, Dtsch Arztebl Int, vol. 111, no. 49, pp. 834-846, Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284520/#s8title.

Johns, D.P., Walters, J.A.E. and Walters, E.H. (2014) ‘Diagnosis and early detection of COPD using spirometry’, Jour, vol. 6, no. 11, pp. 1557-1569, Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4255165/.

Kanwade, A.B. and Bairagi, V. (2016) ‘Analysis of Inspiratory Muscle’, Advances in Signal Processing and Intelligent Recognition Systems, pp. 357-366.

Leupoldt, A.V., Fritzsche, A., Trueba, A.F., Meuret, A.E. and Ritz, T. (2012) ‘Behavioral Medicine Approaches to Chronic Obstructive Pulmonary Disease’, Ann Behav Med, vol. 44, no. 1, pp. 52-65, Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3612952/.

Montuschi, P. (2006) ‘Pharmacological treatment of chronic obstructive pulmonary disease’, Int J Chron Obstruct Pulmon Dis, vol. 1, no. 4, pp. 409–423, Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2707800/.

Nguyen, T.S. and Nguyen, T.L.H. (2018) ‘Pharmacists’ training to improve inhaler technique of patients with COPD in Vietnam’, Dovepress, March, pp. 1863-1872, Available: https://www.dovepress.com/pharmacists-training-to-improve-inhaler-technique-of-patients-with-cop-peer-reviewed-article-COPD.

Sarlabous, L., Torres, A., Fiz, J.A., MartõÂnez-Llorens, J.M., Gea, J. and Jane, R. (2017) ‘Inspiratory muscle activation increases with COPD severity as confirmed by non-invasive mechanomyographic analysis’, PLoS One, May, pp. 1-14.

Torres, A., Sarlabous , L., Fiz , J.A., Gea , J., Martinez-Llorens , J.M., Morera, J. and Jane, R. (2010) ‘Noninvasive Measurement of Inspiratory Muscle Performance by means of Diaphragm Muscle Mechanomyographic Signals in COPD patients during an Incremental Load Respiratory Test’, Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Available: https://www.ncbi.nlm.nih.gov/pubmed/21096168.

Volpato, E., Banfi, P., Rogers, S.M. and Pagnini, F. (2015) ‘Relaxation Techniques for People with Chronic Obstructive Pulmonary Disease: A Systematic Review and a Meta-Analysis’, Evid Based Complement Alternat Med, Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539049/.