Neuromuscular weakness in chronic obstructive pulmonary disease: chest wall, diaphragm, and peripheral muscle contributions

Effects of a cardiopulmonary rehabilitation protocol on functional capacity, dyspnea, fatigue, and body composition in individuals with post-COVID-19 syndrome: A randomized controlled trial

BACKGROUND AND OBJECTIVE

Reduced functional capacity, dyspnea, fatigue, and changes in body composition are common in patients with post-COVID-19 syndrome (PCS), and cardiopulmonary rehabilitation may improve these parameters. Thus, the present study verified the effects of cardiopulmonary rehabilitation (respiratory, aerobic, and resistance muscle training) on submaximal exercise tolerance, dyspnea, fatigue, and body composition.

METHODS

This controlled and randomized clinical trial applied a six-week outpatient intervention protocol in individuals over 18 years old (n = 33) with a diagnosis of COVID-19 confirmed by polymerase chain reaction. These individuals were allocated to cardiopulmonary rehabilitation (n = 17) or control groups (i.e., educational lectures; n = 16). The cardiopulmonary rehabilitation group performed respiratory, aerobic, and resistance muscle training. Submaximal exercise tolerance, dyspnea, fatigue, and body composition were assessed before and after the protocol.

RESULTS

After 6 weeks, the cardiopulmonary rehabilitation group increased the tolerance to submaximal exercise, with a difference of 100.46 m (95% confidence interval [CI]: 7.40-193 m) in the distance walked on the six-minute walk test, reduced dyspnea (-1.45, 95% CI: -1.98--0.92) in the modified Medical Research Council, and increased 0.63 kg (95% CI: 0.09-1.18 kg) of muscle mass in the upper limbs compared with the control group.

CONCLUSION

The six-week cardiopulmonary rehabilitation protocol improved functional capacity, reduced dyspnea, and increased muscle mass in the upper limbs in individuals with PCS. Thus, these results supported the protocol use in this population and encourage further studies to assess its effectiveness in a large sample.

Physiotherapy interventions on chest wall mobility in obstructive lung diseases: A systematic review

PURPOSE

The aim of this systematic review was to investigate the effectiveness of physiotherapy interventions on chest mobility in obstructive lung diseases.

METHODS

Searches were performed in PEDro, Pubmed and Cochrane Central Register of Controlled Trials databases without language restrictions between 2010 and 25th December 2020. Randomized controlled trials (RCTs) investigating physiotherapy interventions on chest wall mobility were included. Two independent reviewers screened studies, extracted data, and assessed methodological quality of included studies. The assessment of risk of bias was conducted using the PEDro scale for RCTs. The articles were excluded if they have less than 5 out of 10 score.

RESULTS

Five studies included had good to excellent quality. A total of 139 patients were included in all RCTs. Intervention duration ranged from a single session to 12 weeks and the intervention schedules varied, consisting of 1-24 sessions, lasting 5-45 min per sessions. Three studies used respiratory muscle stretching and releasing techniques, one study combined respiratory muscle stretching with aerobic training, and one study planned diaphragmatic breathing. Four studies assessed chest wall mobility with optoelectronic plethysmography, whereas one study used measuring tape.

CONCLUSIONS

The result of this first systematic review that investigates the effects of physiotherapy interventions on chest wall mobility in obstructive lung diseases suggests that more and better quality RCTs with objective measurement tools are required.

Non-Invasive Assessment of Abdominal/Diaphragmatic and Thoracic/Intercostal Spontaneous Breathing Contributions

(1) Background: Technically, a simple, inexpensive, and non-invasive method of ascertaining volume changes in thoracic and abdominal cavities are required to expedite the development and validation of pulmonary mechanics models. Clinically, this measure enables the real-time monitoring of muscular recruitment patterns and breathing effort. Thus, it has the potential, for example, to help differentiate between respiratory disease and dysfunctional breathing, which otherwise can present with similar symptoms such as breath rate. Current automatic methods of measuring chest expansion are invasive, intrusive, and/or difficult to conduct in conjunction with pulmonary function testing (spontaneous breathing pressure and flow measurements). (2) Methods: A tape measure and rotary encoder band system developed by the authors was used to directly measure changes in thoracic and abdominal circumferences without the calibration required for analogous strain-gauge-based or image processing solutions. (3) Results: Using scaling factors from the literature allowed for the conversion of thoracic and abdominal motion to lung volume, combining motion measurements correlated to flow-based measured tidal volume (normalised by subject weight) with R2 = 0.79 in data from 29 healthy adult subjects during panting, normal, and deep breathing at 0 cmH2O (ZEEP), 4 cmH2O, and 8 cmH2O PEEP (positive end-expiratory pressure). However, the correlation for individual subjects is substantially higher, indicating size and other physiological differences should be accounted for in scaling. The pattern of abdominal and chest expansion was captured, allowing for the analysis of muscular recruitment patterns over different breathing modes and the differentiation of active and passive modes. (4) Conclusions: The method and measuring device(s) enable the validation of patient-specific lung mechanics models and accurately elucidate diaphragmatic-driven volume changes due to intercostal/chest-wall muscular recruitment and elastic recoil.

Two-dimensional shear wave elastography: a new tool for evaluating respiratory muscle stiffness in chronic obstructive pulmonary disease patients

BACKGROUND

Impaired respiratory function caused by respiratory muscle dysfunction is one of the common consequences of chronic obstructive pulmonary disease (COPD). In this study, two-dimensional shear wave elastography (2D-SWE) was used to measure diaphragm stiffness (DS) and intercostal muscle stiffness (IMS) in patients with COPD; in addition, the value of 2D-SWE in evaluating respiratory function was determined.

METHODS

In total, 219 consecutive patients with COPD and 20 healthy adults were included. 2D-SWE was used to measure the DS and IMS, and lung function was also measured. The correlation between respiratory muscle stiffness and lung function and the differences in respiratory muscle stiffness in COPD patients with different severities were analysed.

RESULTS

2D-SWE measurements of the DS and IMS presented with high repeatability and consistency, with ICCs of 0.756 and 0.876, respectively, and average differences between physicians of 0.10 ± 1.61 and 0.07 ± 1.65, respectively. In patients with COPD, the DS and IMS increased with disease severity (F₁ = 224.50, F₂ = 84.63, P < 0.001). In patients with COPD, the correlation with the forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC), predicted FEV₁% value, residual volume (RV), total lung capacity (TLC), RV/TLC, functional residual capacity (FRC) and inspiratory capacity (IC) of DS (r₁=-0.81, r₂=-0.63, r₃ = 0.65, r₄ = 0.54, r₅ = 0.60, r₆ = 0.72 and r₇=-0.41, respectively; P < 0.001) was stronger than that of IMS (r₁=-0.76, r₂=-0.57, r₃ = 0.57, r₄ = 0.47, r₅ = 0.48, r₆ = 0.60 and r₇=-0.33, respectively; P < 0.001).

CONCLUSION

2D-SWE has potential for use in evaluating DS and IMS. A specific correlation was observed between respiratory muscle stiffness and lung function. With the worsening of the severity of COPD and the progression of lung function impairment, the DS and IMS gradually increased.

Efetividade de diferentes protocolos e cargas utilizadas no treinamento muscular inspiratório de indivíduos com DPOC: uma revisão sistemática

RESUMO A doença pulmonar obstrutiva crônica (DPOC) provoca alterações no sistema musculoesquelético, afetando inclusive os músculos respiratórios e levando ao aumento da dispneia e à redução da capacidade funcional. Nesse sentido, o treinamento muscular inspiratório (TMI) deve fazer parte do programa de reabilitação pulmonar. Diversos estudos já demonstraram sua eficácia, contudo, ainda é necessário investigar qual a melhor forma de realizá-lo. Assim, o objetivo deste estudo foi investigar por meio de uma revisão sistemática a efetividade de diferentes protocolos e cargas de TMI sobre os desfechos de força e resistência dos músculos inspiratórios, bem como de capacidade funcional e redução da dispneia. Trata-se de uma revisão sistemática realizada de acordo com o protocolo PRISMA. A busca foi realizada em fevereiro de 2021, nas seguintes bases de dados: PubMed, SciELO, PEDro. Para a busca dos artigos, os seguintes descritores foram empregados: “COPD”; e “breathing exercises, resistive training, respiratory muscle training”. Um total de 398 pacientes foram incluídos nos 10 estudos selecionados, todos previamente diagnosticados com DPOC. Foram utilizados diferentes dispositivos para o TMI, e os protocolos variaram em relação às cargas e progressão. O dispositivo mais utilizado entre os artigos foi o Threshold, com carga estabelecida de acordo com a porcentagem da pressão inspiratória máxima (30-80%), reajustada de acordo com novas medições a cada uma ou duas semanas. Houve semelhança de resultados positivos encontrados tanto em treinamentos com cargas baixas quanto com cargas altas, havendo uma melhora na força muscular inspiratória, capacidade funcional e dispneia. No entanto, mais estudos são necessários para definir o melhor protocolo de TMI para DPOC.

Effectiveness of different protocols and loads used in inspiratory muscle training of individuals with COPD: a systematic review

ABSTRACT Chronic obstructive pulmonary disease (COPD) changes the musculoskeletal system, including the respiratory muscles, which are responsible for increasing dyspnea and reducing functional capacity. Several studies have already showed the effectiveness of inspiratory muscle training (IMT); therefore, it should be part of the pulmonary rehabilitation program. However, assessing the best way to do it is still necessary. Thus, this study aimed to evaluate, by a systematic review, the effectiveness of different IMT protocols and loads on the outcomes of inspiratory muscle strength and endurance, functional capacity, and dyspnea reduction. This systematic review was performed in accordance with the PRISMA protocol. Studies were searched in February 2021 in the PubMed, SciELO, PEDro. For the search, the following keywords were used: “COPD” and “breathing exercises, resistive training, respiratory muscle training.” A total of 398 individuals previously diagnosed with COPD were included in the 10 selected studies. Different IMT devices were used and protocols varied in relation to loads and progression. Threshold was the most used IMT device. Its load was established according to the percentage of maximal inspiratory pressure (MIP) (30-80%) and readjusted according to new measurements taken every one or two weeks. Respiratory muscle training with both low loads and high loads presented positive results, however, establishing which is the best IMT protocol for individuals with COPD is not possible yet. Inspiratory muscle strength, functional capacity, and dyspnea get better with IMT.

Impact of chronic obstructive pulmonary disease on passive viscoelastic components of the musculoarticular system

Chronic obstructive pulmonary disease (COPD) produces skeletal muscle atrophy and weakness, leading to impairments of exercise performance. The mechanical work needed for movement execution is also provided by the passive tension developed by musculoarticular connective tissue. To verify whether COPD affects this component, the passive viscoelastic properties of the knee joint were evaluated in 11 patients with COPD and in 11 healthy individuals. The levels of stiffness and viscosity were assessed by means of the pendulum test, consisting in a series of passive leg oscillations. In addition, to explore the contribution of passive tension in the mechanical output of a simple motor task, voluntary leg flexion-extension movements were performed. Patients with COPD showed a statistically significant reduction in stiffness and viscosity compared to controls. Voluntary execution of flexion-extension movements revealed that the electromyographic activity of the Rectus Femoris and Biceps Femoris was lower in patients than in controls, and the low viscoelastic tension in the patients conditioned the performance of active movements. These results provide novel insights on the mechanism responsible for the movement impairments associated with COPD.

Application of the respiratory "critical care-sub-critical care-rehabilitation integrated management model" in severe stroke associated pneumonia

Background

This study aimed to explore the feasibility of applying the respiratory “critical care-sub-critical care-rehabilitation integrated management model” in severe stroke-associated pneumonia and evaluate its effect.

Methods

From January to September 2018, 24 patients with severe stroke-associated pneumonia, who were admitted to the Respiratory Intensive Care Unit of the Respiratory and Critical Care Medicine Department of Henan Provincial People’s Hospital, were randomly divided into two groups: integrated management group and control group. According to the admission criteria of the respiratory “critical care-sub-critical care-rehabilitation integrated model” prescribed by the above-mentioned hospital, patients were grouped. The professional respiratory therapy team participated in the whole treatment. The acute physiology and chronic health evaluation II (APACHE II) score, clinical pulmonary infection score (CPIS) and oxygenation index of these two groups were dynamically observed, and the average hospital stay, 28-day mortality and patient satisfaction were investigated.

Results

Patients in the integrated management group and control group were similar before treatment (P > 0.05). After treatment, the main indicators, the APACHE II score, CPIS score and oxygenation index, were significantly different between the integration group and control group (P < 0.05). The secondary indicators, the average hospitalization days and patient/family member satisfaction scores, were also significantly different between the integration group and control group (P < 0.05). However, the 28-day mortality wasn’t significantly different (P > 0.05).

Conclusions

For patients with severe stroke-associated pneumonia, it was feasible to implement the respiratory “critical care-sub-critical care-rehabilitation integrated management model”, which could significantly improve the treatment effect, shorten average hospitalization days and improve patient/family satisfaction.

Aspiration Pneumonia and Related Syndromes

Aspiration is a syndrome with variable respiratory manifestations that span acute, life-threatening illnesses, such as acute respiratory distress syndrome, to chronic, sometimes insidious, respiratory disorders such as aspiration bronchiolitis. Diagnostic testing is limited by the insensitivity of histologic testing, and although gastric biomarkers for aspiration are increasingly available, none have been clinically validated. The leading mechanism for microaspiration is thought to be gastroesophageal reflux disease, largely driven by the increased prevalence of gastroesophageal reflux across a variety of respiratory disorders, including chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis, and chronic cough. Failure of therapies targeting gastric acidity in clinical trials, in addition to increasing concerns about both the overuse of and adverse events associated with proton pump inhibitors, raise questions about the precise mechanism and causal link between gastroesophageal reflux and respiratory disease. Our review summarizes key aspiration syndromes with a focus on reflux-mediated aspiration and highlights the need for additional mechanistic studies to find more effective therapies for aspiration syndromes.

The relationship between exercise capacity and different functional markers in pulmonary rehabilitation for COPD

Rationale

The relationship of functional parameters such as lung mechanics, chest kinematics, metabolism and peripheral and respiratory muscle function with the level of exercise tolerance remains a controversial subject. While it has been previously shown that pulmonary rehabilitation is capable of improving exercise tolerance in patients afflicted by COPD, as expressed by values of 6-minute walking test (6MWT), the degree of contribution to this change by each of the aforementioned parameters remains unclear.

Aims

To investigate the correlation between changes in exercise capacity and other functional markers following pulmonary rehabilitation in COPD and to determine which parameters are more closely related to improvements of exercise tolerance.

Materials and methods

Three hundred and twenty-seven patients with COPD (with average, 95% CI for forced expiratory volume in the first second [FEV₁]: 45% [25%–83%] predicted, age: 64 [48–80] years, and BMI: 27 [13.5–40.4] kg/m²) participated in this study. Thirty percent of the patients had pulmonary hypertension as comorbidity. Patients underwent a pulmonary rehabilitation program with 20–30 minutes sessions two to three times per day for 4 weeks. The program was composed of chest wall-stretching, controlled breathing exercises, and a personalized training schedule for cycling and treadmill use. Measurements of 6MWT, lung function, chest wall expansion, grip strength, maximal inspiratory pressure, and breath holding time were taken. The Body mass index, airflow Obstruction, Dyspnea and Exercise capacity (BODE-index), body mass index [BMI], FEV₁, 6MWT, modified Medical Research Dyspnea Scale score, and an alternative scale score (for BMI, FEV₁, 6MWT, and COPD Assessment Test) were calculated.

Results

Rehabilitation resulted in a generalized improvement in 6MWT among patients (average: 360 [95% CI: 178–543 m] vs average: 420 [95% CI: 238–601 m], p<0.05). Improvements in exercise tolerance were found to be most closely associated with changes in composite BODE-index (R²=−0.6), Alternative Scale (R²=−0.56), dyspnea score (modified Medical Research Dyspnea Scale R²=−0.54), and health status (COPD Assessment Test R²=−0.4, p<0.05). In addition, improvements in exercise tolerance were found to moderately correlate with improvements in inspiratory vital capacity (IVC, R²=0.34, p<0.05). Post-rehabilitation changes in IVC displayed a connection with grip strength (R²=0.6) and chest expansion (R²=0.48).

Conclusion

Enhancements in exercise tolerance had correlation with changes in IVC, BODE-index, and the new Alternative Scale. However, comprehensive assessment needs to include considerations of chest kinematics and peripheral and respiratory muscle function as well.