Respiratory muscle function and exercise limitation in patients with chronic obstructive pulmonary disease: a review

The effects of inspiratory muscle warm-up prior to inspiratory muscle training during pulmonary rehabilitation in subjects with chronic obstructive pulmonary disease: a randomized trial

BACKGROUND

While a whole-body warm-up may not adequately prepare the inspiratory muscles for exercise, inspiratory warm-up is an effective approach in preparing the inspiratory muscles for exertion.

OBJECTIVES

To investigate the effects of inspiratory muscle warm-up performed prior to inspiratory muscle training (IMT) during pulmonary rehabilitation (PR) in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) and inspiratory muscle weakness.

METHODS

Pulmonary function tests, maximal inspiratory and expiratory pressures (MIP and MEP), 6-minute walk test distance (6MWD), modified Medical Research Council Dyspnea Scale(mMRC), St. George's respiratory questionnaire and the 36-item short-form health survey were evaluated. Both groups performed IMT during PR for 8 weeks. The warm-up group (n = 15), in addition to the standard IMT group (n = 15), performed an inspiratory muscle warm-up protocol before each IMT session.

RESULTS

At the end of the 8-week intervention, improvements in dyspnea (mMRC in score, p =0.033, effect size =0.76); exercise capacity (6MWD in meters, p =0.001, effect size =1.30); pulmonary function [forced expiratory volume in 1 second (FEV1) in %predicted, p =0.006, effect size =1.10]; and inspiratory muscle strength (MIP in cmH2O, p =0.001, effect siz e = 1.35) were significantly greater in the warm-up group. Moreover, there were significant improvements in health-related quality of life (HRQoL) sub-scores after the training in both groups (p <0.05).

CONCLUSIONS

This study demonstrated improvements in both groups, surpassing or closely approaching the established minimal clinically important difference values for the respective outcomes. Performing a warm-up for inspiratory muscles before IMT boosts benefits for pulmonary function, inspiratory muscle strength, exercise capacity, dyspnea, and HRQoL in subjects with moderate-to-severe COPD and inspiratory muscle weakness.

Impact of Preliminary Bronchodilator Dose in Chronic Obstructive Pulmonary Disease Patients With Suboptimal Peak Inspiratory Flow

PURPOSE

Suboptimal peak inspiratory flow rate (PIFR) is highly prevalent in patients with chronic obstructive pulmonary disease (COPD) owing to the mismatch of their PIFR with the corresponding inhaler-device resistance. This study aimed to investigate the impact of a preliminary dose of pressurized metered dose inhalers (pMDIs) on patients with COPD with suboptimal PIFR using Diskus dry powder inhalers (DPIs).

METHODS

A prospective, randomized, case-control study included 24 patients with COPD. PIFR was measured using the In-Check Dial G16 with low-to-medium resistance. Spirodoc was used to measure baseline spirometric data and compare it before and 30 minutes after the administration of Diskus DPI. On a different day, the study dose was given to each suboptimal patient by the same aerosol generator with preceded 2 puffs of salbutamol pMDI and re-evaluated for spirometric parameters 30 minutes after the study dose.

FINDINGS

There was a significant difference between the optimal and suboptimal groups in peak expiratory flow (2.38 ± 1.20 vs 1.49 ± 1.06 L/s, P = 0.050). PIFR showed a statistically significant difference between the optimal and suboptimal groups (71.66 ± 6.15 vs 41.25 ± 9.79 L/min, P < 0.0001). There was a significant difference in forced vital capacity (ΔFVC) between optimal and suboptimal groups without a preliminary dose (0.42 ± 0.21 vs 0.16 ± 0.11 L, P = 0.002), forced expiratory volume in 6 seconds (ΔFEV6) (0.53 ± 0.49 vs 0.17 ± 0.11 L, P = 0.022), forced expiratory volume in 3 seconds (ΔFEV3) (0.41 ± 0.38 vs 0.1 ± 0.16 L, P = 0.013), forced expiratory volume in 1 second (ΔFEV1)/FVC (-2.38 ± 8.41 vs 2.96% ± 2.95%, P = 0.033), and ΔFEV1/FEV6 (-4.32 ± 11.23 vs 2.91% ± 4.35%, P = 0.015). There was a significant difference in ΔFVC between optimal and suboptimal groups with a preliminary dose (0.42 ± 0.21 vs 0.23 ± 0.18 L, P = 0.046), ΔFEV1/FVC (-2.38 ± 8.41 vs 5.67% ± 6.53%, P = 0.009), ΔFEV1/FEV6 (-4.32 ± 11.23 vs 5.16% ± 4.99%, P = 0.008), and forced expiratory time (ΔFET) (0.28 ± 0.45 vs -0.31 ± 0.70 seconds, P = 0.022). The only parameter that showed a significant difference between suboptimal groups without and with a preliminary dose is Δ peak expiratory flow (0.24 ± 0.59 vs 0.65 ± 0.68 L/s, P = 0.004).

IMPLICATIONS

Administering a preliminary dose of pMDI can minimally enhance the effectiveness of DPIs in patients with COPD with suboptimal PIFR and health outcomes.

Effect of Inspiratory Muscle Training on Cough Strength in Older People With Frailty: A Single-Blind Randomized Controlled Trial

OBJECTIVE

To investigate the effect of inspiratory muscle training (IMT) on cough strength in older people with frailty.

DESIGN

Single-blind randomized controlled trial.

SETTING

Day health care centers at 2 sites.

PARTICIPANTS

Older people with frailty (N=60).

INTERVENTIONS

Eligible people were randomly assigned to receive IMT program in addition to general exercise training (IMT group), or general exercise training alone (control group). The IMT group performed training using a threshold IMT device with the load set at 30% of maximum inspiratory mouth pressure in addition to the general exercise training program throughout the 8 weeks. The IMT took place twice a day and each session consisted of 30 breaths.

MAIN OUTCOME MEASURES

Primary outcome was cough strength, measured as the cough peak flow (CPF), at the beginning and the end of the program.

RESULTS

Data from 52 participants (26 in each group) were available for the analysis. The mean age was 82.6 years; 33% were men. The change in CPF at the end of the program was 28.7±44.4 L/min in the IMT group and -7.4±26.6 L/min in the control group. A linear regression model showed that the presence or absence of IMT was associated with changes in CPF (mean difference between groups, 36.3; 95% confidence interval, 16.7-55.9; effect size, 0.99).

CONCLUSIONS

IMT may be a useful intervention to improve cough strength in frail older people.

Effects of 12 weeks of inspiratory muscle training and whole body vibration on the inflammatory profile, BDNF and muscular system in pre-frail elderly women: A randomized controlled trial

AIM

to investigate the effects of the whole body vibration (WBV) and inspiratory muscle training (IMT) on the inflammatory profile and in muscle mass and strength in pre-frail older women.

METHODS

this study was a randomized double-blind trial. Forty two older women aged 60-80 years were randomly allocated to IMT + WBV (G1), IMTsham + WBV (G2) or Sham groups (G3). During 12 weeks G1 received both trainings, whereas G2 received WBV alone and G3 received IMT with a low fixed load and were positioned at the vibratory platform without therapeutic effect. Participants were evaluated before and after the intervention for the following outcomes: Brain-derived neurotrophic factor (BDNF) and inflammatory biomarkers (IB), respiratory (RT) and quadriceps thickness (QT) and diaphragmatic mobility (DM) using muscle ultrasound, body composition (BC) using a bioelectrical impedance scale and inspiratory muscle strength (IMS).

RESULTS

after the training, G1 (114.93 ± 21.29) improved IMS (p<0.005) compared with G2 (91.29 ± 23.10) and G3 (85.21 ± 27.02). There was also a significant improve on time of the DM (p<0.001) and RT (p=0.006) for G1 (8.59 ± 3.55 and 11.11 ± 12.66) compared with G2 (1.05 ± 3.09 and 1.10 ± 10.60) and G3 (0.40 ± 2.29 and -1.85 ± 7.45). BDNF, IB, QT and BC were similar between groups.

CONCLUSIONS

IMT associated with WBV is effective to improve in increasing IMS, RT and DM in pre-frail older women. However, these interventions do not modify BDNF, IB, QT or BC in this population.

Manual Therapy Interventions in Patients With Chronic Obstructive Pulmonary Disease: A Comprehensive Narrative Review

Chronic obstructive pulmonary disease (COPD) is a breathing problem with ongoing airflow issues and changes in how the chest moves. Different manual therapy methods, like releasing the diaphragm, manipulating the spine and joints, and treating soft tissues, have been used for people with COPD. This review looks into how these manual therapy approaches affect COPD patients. Articles were searched in Google Scholar, PubMed, and Elsevier using keywords such as COPD, manual therapy, thoracic excursion, and pulmonary function. Only studies conducted between 2015 and 2023, employing randomized controlled trials (RCTs), crossover RCTs, or comparative studies with COPD subjects, thoracic excursion, chest expansion, or pulmonary function tests (PFTs) as outcome measures, and involving physiotherapy interventions were included. Out of 82 articles searched, 10 met the inclusion criteria, comprising six RCTs, three crossover RCTs, and one comparative study. Data extraction was performed by one reviewer, encompassing intervention descriptions, inclusion/exclusion criteria, baseline data, and outcome values. The findings suggest that conventional physiotherapy combined with manual therapy techniques such as stretching, osteopathic manual therapy, manual diaphragmatic release, soft tissue therapy, and spinal manipulation have improved thoracic excursion and pulmonary function in COPD patients. Therefore, these manual therapy techniques are recommended for enhancing thoracic excursion and pulmonary function in COPD patients.

Incremental Load Respiratory Muscle Training Improves Respiratory Muscle Strength and Pulmonary Function in Children with Bronchiectasis

Methods

Participants underwent respiratory muscle training for 24 weeks. The main results were changes in respiratory muscle strength and pulmonary function indices (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow rate (PEF), forced expiratory flow 25-75% (FEF25-75%), and maximal midexpiratory flow 75/25 (MMEF75/25)) before, 12 weeks after, and 24 weeks after the intervention. The secondary outcomes were changes in the exercise load and work rate, exercise work, Leicester Cough Questionnaire (LCQ) scale, and Fatigue Severity Scale (FSS).

Results

Compared with before the intervention, after 24 weeks of respiratory muscle training, the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were significantly enhanced (P < 0.05), while FVC, FEV1, and PEF were significantly increased (P < 0.01). FEF25-75 and MMEF75/25 values showed significant improvement compared to those before training (P < 0.05). The exercise loading, work, and exercise work rate of expiratory muscle training were significantly improved compared to those before intervention (P < 0.05). The LCQ score increased significantly (P <  0.001), and the FSS score decreased significantly (P <  0.001).

Conclusion

Incremental load respiratory muscle training effectively improved children's lung function over the long term, improved the strength of their inspiratory and expiratory muscles, and improved their quality of life.

The effect of acupuncture on exercise capacity in patients with COPD is mediated by improvements of dyspnea and leg fatigue: a causal mediation analysis using data from a randomized controlled trial

BACKGROUND

Acupuncture is known to improve exercise capacity in patients with chronic obstructive pulmonary disease (COPD), but its mechanism remains unknown. Whether acupuncture improves exercise capacity in patients with COPD through alleviation of leg fatigue and dyspnea is examined by applying causal mediation analysis to previous trial data.

METHODS

Sixty-two patients with COPD completed treatments with either real or placebo acupuncture once a week for 12 weeks. Walk distance measured using the 6-minute walk test and intensities of leg fatigue and dyspnea in the modified Borg scale were evaluated at baseline and after treatment. The intervention effect of acupuncture against the placebo acupuncture on two mediators, changes in leg fatigue and dyspnea, and whether they mediated improvements in walk distance, were analyzed.

RESULTS

Linear regression analysis showed that the unstandardized regression coefficients [95% confidence interval (CI)] for the intervention effect by acupuncture were -4.9 (-5.8--4.0) in leg fatigue and -3.6 (-4.3--2.9) in dyspnea. Mediation analysis showed that when changes in leg fatigue were considered as a mediator, direct effect, indirect effect and proportion mediated were 47.1 m (95% CI, 4.6-85.1), 34.3 m (-2.1-82.1), and 42.1%, respectively, and when changes in dyspnea were considered as a mediator, they were 9.8 m (-32.9-49.9), 72.5 m (31.3-121.0), and 88.1%, respectively, and the effects of joint mediator were -5.8 m (-55.4-43.9), 88.9 m (32.7-148.5), and 107.0%, respectively.

CONCLUSION

The improvement in exercise capacity by acupuncture is explained by changes in both leg fatigue and dyspnea.

Can inspiratory muscle training benefit patients with COVID-19? A systematic review and meta-analysis

The possible benefits of inspiratory muscle training (IMT) on mechanical and clinical outcomes in patients with Coronavirus disease-2019 (COVID-19) remain controversial. We conducted a meta-analysis to evaluate the effect of IMT in the rehabilitation strategy of patients with COVID-19. The Pubmed, Embase, Web of Science (WOS), and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify trials evaluating the efficacy of IMT in the treatment of patients with COVID-19. The primary outcome included change from baseline of VO2 max, maximal inspiratory pressure (PImax), 6-min walk test(6MWT), forced expiratory volume in the first second predicted (FEV1%pred), and quality of life (QOL). Six studies with 349 participants were analyzed. Significant improvements were found in change from baseline of VO2 max (MD: 4.54, 95% confidence interval [CI]: 1.79-7.30, Z = 3. 32, I2  = 0, p = 0.001), PImax (MD: 21.43, 95% CI: 1.33-41.52, Z = 2.09, I2  = 90%, p = 0.04), 6MWD (MD: 40.13, 95% CI: 24.92-55.35, Z = 5.17, I2  = 0, p < 0.00001) and FEV1%pred (MD: 8.73, 95% CI 3.07-14.39, Z = 3.02, p = 0.002) while no statistical improvements were found in QOL (SMD: 0.70, 95% CI: 0.37-1.03, Z = 4.15, I2  = 89% p = 0.32) between IMT group and control group. The application of IMT might elicit mechanical and clinical improvement in patients with COVID-19. IMT could be recommended as an effective strategy of pulmonary rehabilitation for COVID-19. However, the proper timing, optimal duration, as well as appropriate frequency and intensity of IMT remain uncertain and further studies are needed.

Comparison of Effects of Liuzijue Exercise and Conventional Respiratory Training on Patients after Cardiac Surgery: A Randomized Controlled Trial

OBJECTIVE

To evaluate the feasibility and safety of Liuzijue exercise (LE) for the clinical effect in patients after cardiac surgery.

METHODS

Totally 120 patients who underwent cardiac surgery and were admitted to the Cardiothoracic Intensive Care Unit of Nanjing Drum Tower Hospital between July and Oclober, 2022 were allocated to the LE group, the conventional respiratory training (CRT) group, and the control group by a random number table at a ratio of 1:1:1; 40 patients in each group. All patients received routine treatment and cardiac rehabilitation. LE group and CRT group respectively performed LE and CRT once a day for 30 min for 7 days. Control group did not receive specialized respiratory training. The forced vital capacity, forced expiratory volume in 1 s, peak inspiratory flow rate, peak expiratory flow rate, maximum inspiratory pressure, maximum expiratory pressure, modified Barthel index (MBI), and Hamilton Rating Scale for Anxiety (HAM-A) were evaluated before, after 3 and 7 days of intervention. In addition, the postoperative length of hospital stay (LOS) and the adverse events that occurred during the intervention period were compared.

RESULTS

A total of 107 patients completed the study, 120 patients were included in the analysis. After 3 days of intervention, the pulmonary function, respiratory muscle strength, MBI and HAM-A of all 3 groups improved compared with that before the intervention (P<0.05 or P<0.01). Compared with the control group, pulmonary function and respiratory muscle strength were significantly improved in the CRT and LE groups (P<0.05 or P<0.01). MBI and HAM-A were significantly improved in the LE group compared with the control and CRT groups (P<0.05 or P<0.01). On the 7th day after intervention, the difference was still statistically significant (P<0.01), and was significantly different from that on the 3rd day (P<0.05 or P<0.01). In addition, on the 7th day of intervention, the pulmonary function and respiratory muscle strength in the LE group were significantly improved compared with those in the CRT group (P<0.01). MBI and HAM-A were significantly improved in the CRT group compared with the control group (P<0.01). There were no significant differences in postoperative LOS among the 3 groups (P>0.05). No training-related adverse events occurred during the intervention period.

CONCLUSIONS

LE is safe and feasible for improving pulmonary function, respiratory muscle strength, the ability to complete activities of daily living and for relieving anxiety of patients after cardiac surgery (Registration No. ChiCTR2200062964).

Quantitative evaluation of diaphragmatic motion during forced breathing in chronic obstructive pulmonary disease patients using dynamic chest radiography

Objective

To quantitatively evaluate the bilateral diaphragmatic motion difference during forced breathing between chronic obstructive pulmonary disease (COPD) patients and healthy individuals using dynamic chest radiography technique.

Methods

This prospective study included the COPD patients (n: 96, f/m: 17/79, age: 66 ± 8 years old) and healthy individuals (n: 50, f/m: 42/8, age: 53 ± 5 years old) that underwent dynamic chest radiography with a flat panel X-ray detector system during forced breathing in a standing position. After analyzing the excursions, duration and velocity of diaphragmatic motion were automatically calculated using the postprocessing software. The parameters of diaphragmatic motion including excursion, duration, velocity, inhalation/exhalation times were assessed in all subjects for both diaphragms. The correlation between lung function parameters and diaphragmatic motion excursions were further evaluated.

Results

The excursions of diaphragmatic motion in COPD patients were significantly decreased in COPD patients compared with healthy individuals during forced breathing (P < 0.05). The excursion in COPD patients was 35.93 ± 13.07 mm vs. 41.49 ± 12.07 mm in healthy individuals in the left diaphragm, and 32.05 ± 12.29 mm in COPD patients vs. 36.88 ± 10.96 mm in healthy individuals in the right diaphragm. The duration of diaphragmatic motion significantly decreased in COPD patients, compared with the healthy individuals (P < 0.05). The inhalation time in COPD patients was 2.03 ± 1.19 s vs. 2.53 ± 0.83 s in healthy individuals in the left diaphragm and 1.94 ± 1.32 s in COPD patients vs. 2.23 ± 1.21 s in healthy individuals in the right diaphragm. The exhalation time was 4.77 ± 1.32 s in COPD patients vs. 6.40 ± 2.73 s in healthy individuals in the left diaphragm and 4.94 ± 3.30 s in COPD patients vs. 6.72 ± 2.58 s in healthy individuals in the right diaphragm. The peak velocity of diaphragmatic motion showed no significant difference between COPD and healthy groups. The excursions of bilateral diaphragmatic motion showed moderate correlation with FEV1/FVC (r = 0.44, P < 0.001). Multi-linear regression analysis showed that the excursions of bilateral diaphragm are significantly associated with COPD occurrence (P < 0.05).

Conclusion

The excursions and duration of diaphragmatic motion during forced breathing are significantly decreased in COPD patients, compared with healthy individuals. Our study showed that precise bilateral diaphragmatic motion activity can be evaluated by dynamic chest radiography.

A Retrospective Study of Diaphragmatic Breathing Training Combined with Discharge Care Bundles in Patients with Chronic Obstructive Pulmonary Disease

Objective. Both physical exercise and discharge care bundles can improve patient outcomes and reduce hospitalization rates among subjects with chronic obstructive pulmonary disease (COPD). The retrospective analysis aims to determine the advantages of care bundles combined with diaphragmatic breathing training (DBT) in COPD patients after discharge. Methods. Of the 110 COPD patients, 55 patients received DBT alone (DBT group) and 55 participants received the combined intervention (care bundle + DBT group). Three months after discharge, we assessed the outcomes of patients using Bristol COPD Knowledge Questionnaire (BCKQ), Hospital Anxiety and Depression Scale (HADS), COPD Assessment Test (CAT), and St. George’s Respiratory Questionnaire (SGRQ). Meanwhile, COPD-related hospital readmissions were also recorded. Results. The BCKQ score for assessing the disease knowledge level was increased in patients at 3 months after the combined interventions as compared to the baseline values, which was higher in the care bundle + DBT group than the DBT group at 3 months. Moreover, improvements in negative emotion and clinical symptoms from baseline to 3-month follow-up were seen in both the two groups. Besides, the care bundle + DBT group showed the mitigation of depression and anxiety and the alleviation of clinical symptoms in comparison with the DBT group at 3 months. Participants who received combined interventions had lower SGRQ scores than those who received DBT alone. The time to first COPD-related readmission was shorter for patients in the care bundle + DBT group compared with the DBT group. Conclusions. DBT combined with discharge care bundles for COPD patients resulted in improvements in disease-specific knowledge, negative emotions, and clinical symptoms with better HRQOL and lower readmission rate.

Physiological Predictors of Morbidity and Mortality in COPD: The Relative Importance of Reduced Inspiratory Capacity and Inspiratory Muscle Strength

Low resting inspiratory capacity (IC) and low maximal inspiratory pressure (MIP) have previously been linked to exertional dyspnea, exercise limitation and poor survival in chronic obstructive pulmonary disease (COPD). The interaction and relative contributions of these two related variables to important clinical outcomes are unknown. The objective of the current study was to examine the interaction between resting IC and MIP (both % predicted), exertional dyspnea, exercise capacity and long-term survival in patients with COPD. Two hundred and eighty-five patients with mild to advanced COPD completed standard lung function testing and a cycle cardiopulmonary exercise test. Multiple regression determined predictors of the exertional dyspnea-ventilation slope and peak oxygen uptake (V̇O_2peak). Cox regression determined predictors of 10-year mortality. IC was associated with the dyspnea-ventilation slope (standardized β=-0.44, p<0.001), while MIP was excluded from the regression model (p=0.713). IC and MIP were included in the final model to predict V̇O_2peak. However, the standardized β was greater for IC (0.49) than MIP (0.22). After adjusting for age, sex, body mass index, cardiovascular risk, airflow obstruction and diffusing capacity, resting IC was independently associated with 10-year all-cause mortality (hazard ratio=1.25, confidence interval_5-95%=1.16-1.34, p<0.001), while MIP was excluded from the final model (all p=0.829). Low resting IC was consistently linked to heightened dyspnea intensity, low V̇O_2peak and worse survival in COPD even after accounting for airway obstruction, inspiratory muscle strength, and diffusing capacity. These results support the use of resting IC as an important physiological biomarker closely linked to key clinical outcomes in COPD.

Inspiratory Muscle Training Enhances Recovery Post COVID-19: A Randomised Controlled Trial

Background

Many people recovering from coronavirus disease 2019 (COVID-19) experience prolonged symptoms, particularly breathlessness. We urgently need to identify safe and effective COVID-19 rehabilitative strategies. The aim of the current study was to investigate the potential rehabilitative role of inspiratory muscle training (IMT).

Methods

281 adults (age 46.6±12.2 years; 88% female) recovering from self-reported COVID-19 (9.0±4.2 months post-acute infection) were randomised 4:1 to an 8-week IMT or a “usual care” waitlist control arm. Health-related quality-of-life and breathlessness questionnaires (King's Brief Interstitial Lung Disease (K-BILD) and Transition Dyspnoea Index (TDI)), respiratory muscle strength, and fitness (Chester Step Test) were assessed pre- and post-intervention. The primary end-point was K-BILD total score, with the K-BILD domains and TDI being key secondary outcomes.

Results

According to intention to treat, there was no difference between groups in K-BILD total score post-intervention (control: 59.5±12.4; IMT: 58.2±12.3; p<0.05) but IMT elicited clinically meaningful improvements in the K-BILD domains for breathlessness (control: 59.8±12.6; IMT: 62.2±16.2; p<0.05) and chest symptoms (control: 59.2±18.7; IMT: 64.5±18.2; p<0.05), along with clinically meaningful improvements in breathlessness according to TDI (control: 0.9±1.7 versus 2.0±2.0; p<0.05). IMT also improved respiratory muscle strength and estimated aerobic fitness.

Conclusions

IMT may represent an important home-based rehabilitation strategy for wider implementation as part of COVID-19 rehabilitative strategies. Given the diverse nature of long COVID, further research is warranted on the individual responses to rehabilitation; the withdrawal rate herein highlights that no one strategy is likely to be appropriate for all.

IMT can significantly improve breathlessness and respiratory muscle function in people with long COVID, and represents an effective, home-based rehabilitation strategy that could be widely implemented as part of COVID-19 recovery strategieshttps://bit.ly/3HiEyz0

Can Non-invasive Ventilation Modulate Cerebral, Respiratory, and Peripheral Muscle Oxygenation During High-Intensity Exercise in Patients With COPD-HF?

Aim

To evaluate the effect of non-invasive positive pressure ventilation (NIPPV) on (1) metabolic, ventilatory, and hemodynamic responses; and (2) cerebral (Cox), respiratory, and peripheral oxygenation when compared with SHAM ventilation during the high-intensity exercise in patients with coexisting chronic obstructive pulmonary disease (COPD) and heart failure (HF).

Methods and Results

On separate days, patients performed incremental cardiopulmonary exercise testing and two constant-work rate tests receiving NIPPV or controlled ventilation (SHAM) (the bilevel mode—Astral 150) in random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin (OxyHb+Mb) and deoxyhemoglobin (DeoxyHb+Mb) were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, The Netherlands). NIPPV associated with high-intensity exercise caused a significant increase in exercise tolerance, peak oxygen consumption (V·O2 in mlO₂·kg⁻¹·min⁻¹), minute ventilation peak (V·E in ml/min), peak peripheral oxygen saturation (SpO₂, %), and lactate/tlim (mmol/s) when compared with SHAM ventilation. In cerebral, respiratory, and peripheral muscles, NIPPV resulted in a lower drop in OxyHb+Mb (p < 0.05) and an improved deoxygenation response DeoxyHb+Mb (p < 0.05) from the half of the test (60% of Tlim) when compared with SHAM ventilation.

Conclusion

Non-invasive positive pressure ventilation during constant work-rate exercise led to providing the respiratory muscle unloading with greater oxygen supply to the peripheral muscles, reducing muscle fatigue, and sustaining longer exercise time in patients with COPD-HF.

Time to Move Beyond a "One-Size Fits All" Approach to Inspiratory Muscle Training

Inspiratory muscle training (IMT) has been studied as a rehabilitation tool and ergogenic aid in clinical, athletic, and healthy populations. This technique aims to improve respiratory muscle strength and endurance, which has been seen to enhance respiratory pressure generation, respiratory muscle weakness, exercise capacity, and quality of life. However, the effects of IMT have been discrepant between populations, with some studies showing improvements with IMT and others not. This may be due to the use of standardized IMT protocols which are uniformly applied to all study participants without considering individual characteristics and training needs. As such, we suggest that research on IMT veer away from a standardized, one-size-fits-all intervention, and instead utilize specific IMT training protocols. In particular, a more personalized approach to an individual's training prescription based upon goals, needs, and desired outcomes of the patient or athlete. In order for the coach or practitioner to adjust and personalize a given IMT prescription for an individual, factors, such as frequency, duration, and modality will be influenced, thus inevitably affecting overall training load and adaptations for a projected outcome. Therefore, by integrating specific methods based on optimization, periodization, and personalization, further studies may overcome previous discrepancies within IMT research.

Adjunctive inspiratory muscle training for patients with COVID-19 (COVIDIMT): protocol for randomised controlled double-blind trial

INTRODUCTION

A significant number of patients with COVID-19 may experience dyspnoea, anxiety, depression, pain, fatigue and physical impairment symptoms, raising the need for a multidisciplinary rehabilitation approach, especially for those with advanced age, obesity, comorbidities and organ failure. Traditional pulmonary rehabilitation (PR), including exercise training, psychosocial counselling and education, has been employed to improve pulmonary function, exercise capacity and quality of life in patients with COVID-19. However, the effects of inspiratory muscle training (IMT) in PR programmes remain unclear. This study aimed to determine whether the addition of a supervised IMT in a PR is more effective than PR itself in improving dyspnoea, health-related quality of life and exercise capacity in symptomatic patients with post-COVID-19.

METHODS AND ANALYSIS

This parallel-group, assessor-blinded randomised controlled trial, powered for superiority, aimed to assess exercise capacity as the primary outcome. A total of 138 are being recruited at two PR centres in Brazil. Following baseline testing, participants will be randomised using concealed allocation, to receive either (1) standard PR with sham IMT or (2) standard PR added to IMT. Treatment effects or differences between the outcomes (at baseline, after 8 and 16 weeks, and after 6 months) of the study groups will be analysed using an ordinary two-way analysis of variance.

ETHICS AND DISSEMINATION

This trial was approved by the Brazilian National Ethics Committee and obtained approval on 7 October 2020 (document number 4324069). The findings will be disseminated through publications in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04595097.

Reliability and validity of six-minute step test in patients with heart failure

Exercise intolerance is the hallmark consequence of advanced chronic heart failure (HF). The six-minute step test (6MST) has been considered an option for the six-minute walk test because it is safe, inexpensive, and can be applied in small places. However, its reliability and concurrent validity has still not been investigated in participants with HF with reduced ejection fraction (HFrEF). Clinically stable HFrEF participants were included. Reliability and error measurement were calculated by comparing the first with the second 6MST result. Forty-eight hours after participants underwent the 6MST, they were invited to perform a cardiopulmonary exercise test (CPET) on a cycle ergometer. Concurrent validity was assessed by correlation between number of steps and peak oxygen uptake (V̇O2 peak) at CPET. Twenty-seven participants with HFrEF (60±8 years old and left ventricle ejection fraction of 41±6%) undertook a mean of 94±30 steps in the 6MST. Intra-rater reliability was excellent for 6MST (ICC=0.9), with mean error of 4.85 steps and superior and inferior limits of agreement of 30.6 and -20.9 steps, respectively. In addition, strong correlations between number of steps and CPET workload (r=0.76, P<0.01) and peak V̇O2 (r=0.71, P<0.01) were observed. From simple linear regression the following predictive equations were obtained with 6MST results: V̇O2 peak (mL/min) = 350.22 + (7.333 × number of steps), with R2=0.51, and peak workload (W) = 4.044 + (0.772 × number of steps), with R2=0.58. The 6MST was a reliable and valid tool to assess functional capacity in HFrEF participants and may moderately predict peak workload and oxygen uptake of a CPET.

Vitamin C deficiency and risk of metabolic complications among adults with chronic respiratory diseases: A case-control study

BACKGROUND

Chronic respiratory disease (CRD) is an airflow limitation that represents a wide array of serious diseases. The aim of this study is to examine the influence of vitamin C deficiency on metabolic health-related quality in individuals with and without chronic respiratory disease in the Gaza Strip.

METHODS

A matched case-control study including 52 cases of CRD and 52 controls of healthy participants were matched by age, sex, body mass index (BMI) and waist circumferences (WC). The study was conducted at the Ministry of Health secondary health-care centers in Gaza strip, Palestine. The biochemical data included Protein Carbonyl (PC), high sensitivity C reactive protein (CRP), vitamin C, fasting blood glucose (FBG) and markers of the lipid profile.

RESULTS

By the qualitative estimation of vitamin C consumption, there was a significantly lower consumption of foods that are rich in vitamin C by CRD patients than the matched controls. By comparing the results between both groups, CRD patients had significantly lower plasma concentrations of vitamins C than the control group (18.43 ± 11.93 μgm/ml vs. 24.06 ± 11.19 μgm/ml, P = 0.025), but significantly higher in PC (3.86 ± 4.21 μgm/ml vs. 2.11 ± 0.97 μgm/ml, P = 0.005), CRP (5.98 ± 8.84 mg/l vs. 1.87 ± 1.96 mg/l, P = 0.001), and FBG (102.46 ± 15.09 mg/dl vs. 95.92 ± 10.88 mg/dl, P = 0.017). The results revealed that CRD patients had significantly lower blood oxygen saturation than the control group (96.36 ± 3.81 vs. 98.51 ± 0.75, P < 0.001), whereas no significant differences were observed regarding the lipid profiles markers.

CONCLUSION

CRD patients have lower levels of vitamin C in their plasma and their diet than do healthy matched people; they also have higher oxidative stress and inflammatory markers than healthy people, which are risk factors for predicting metabolic complications.

Association of Body Mass Index with Risk of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

The association between body mass index (BMI) and chronic obstructive pulmonary disease (COPD) remains controversial. Therefore, a meta-analysis was conducted to further evaluate the relationship. A comprehensive literature search was performed in PubMed, Web of Science, EMBASE, China National Knowledge Infrastructure (CNKI), and Wanfang databases to identify eligible articles until July 15, 2020. Random effect model (REM) was used to compute the pooled results with 95% confidence intervals (CIs). We conducted meta-regression and subgroup analysis to explore potential sources of heterogeneity. Publication bias was evaluated by funnel plots and Egger's test. Thirty articles with 1,578,449 participants were included in the meta-analysis. The pooled OR of COPD was 1.96 (95% CI: 1.78-2.17) for the underweight group, 0.80 (95% CI: 0.73-0.87) for overweight group, and 0.86 (95% CI: 0.73-1.02) for obesity group. After further excluding 5 studies of high between-study heterogeneity in sensitivity analysis, the pooled OR of COPD was 0.77 (95% CI: 0.68-0.86) for the obesity group. This meta-analysis indicated that BMI was associated with COPD. Specifically, underweight might increase the risk of COPD; overweight and obesity might reduce the risk of COPD.

How Breathing Exercises Influence on Respiratory Muscles and Quality of Life among Patients with COPD? A Systematic Review and Meta-Analysis

Aim

This systematic review aimed to investigate the effect of different breathing exercises on respiratory muscle function, 6-minute walk test (6MWT), and quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD).

Methods

We searched online databases including PubMed, Embase, Web of Science, Cochrane Library, and Ovid for randomized controlled trials that assessed the efficacy of breathing exercises on patients with COPD. Patient outcome parameters included changes in respiratory muscle function, 6MWT, and QoL. The Cochrane Collaboration tool was used to assess the risk of bias for each included study. Subgroup analyses concerning different interventions and outcome measurements were conducted as necessary. PROSPERO registration number is CRD42018118367.

Results

A total of 17 studies were included for final analysis. Meta-analysis based on the relevant studies showed that breathing exercises had a significant total effect on pulmonary function PImax (mean difference (MD) = 8.65, 95% confidence interval (CI) 3.13-14.16, P=0.002), as well as 6MWT (MD = 27.70, 95% CI 5.45-49.94, P=0.01) in patients with COPD.

Conclusions

This systematic review summarized the use of breathing exercises for treating patients with COPD. Breathing exercises were found to be an effective tool for treating patients with COPD by improving inspiratory muscle strength and 6MWT. However, breathing exercises showed no significant improvements on the QoL of patients with COPD.

Current developments and future directions in respiratory physiotherapy

Respiratory physiotherapists have a key role within the integrated care continuum of patients with respiratory diseases. The current narrative review highlights the profession's diversity, summarises the current evidence and practice, and addresses future research directions in respiratory physiotherapy. Herein, we describe an overview of the areas that respiratory physiotherapists can act in the integrated care of patients with respiratory diseases based on the Harmonised Education in Respiratory Medicine for European Specialists syllabus. In addition, we highlight areas in which further evidence needs to be gathered to confirm the effectiveness of respiratory therapy techniques. Where appropriate, we made recommendations for clinical practice based on current international guidelines.

Lung Function Testing in Chronic Obstructive Pulmonary Disease

Lung function testing has undisputed value in the comprehensive assessment and individualized management of chronic obstructive pulmonary disease, a pathologic condition in which a functional abnormality, poorly reversible expiratory airway obstruction, is at the core of its definition. After an overview of the physiologic underpinnings of the disease, the authors outline the role of lung function testing in this disease, including diagnosis, assessment of severity, and indication for and responses to pharmacologic and nonpharmacologic interventions. They discuss the current controversies surrounding test interpretation with these purposes in mind and provide balanced recommendations to optimize their usefulness in different clinical scenarios.

Heart, lungs, and muscle interplay in worsening activity-related breathlessness in advanced cardiopulmonary disease

PURPOSE OF REVIEW

Activity-related breathlessness is a key determinant of poor quality of life in patients with advanced cardiorespiratory disease. Accordingly, palliative care has assumed a prominent role in their care. The severity of breathlessness depends on a complex combination of negative cardiopulmonary interactions and increased afferent stimulation from systemic sources. We review recent data exposing the seeds and consequences of these abnormalities in combined heart failure and chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

The drive to breathe increases ('excessive breathing') secondary to an enlarged dead space and hypoxemia (largely COPD-related) and heightened afferent stimuli, for example, sympathetic overexcitation, muscle ergorreceptor activation, and anaerobic metabolism (largely heart failure-related). Increased ventilatory drive might not be fully translated into the expected lung-chest wall displacement because of the mechanical derangements brought by COPD ('inappropriate breathing'). The latter abnormalities, in turn, negatively affect the central hemodynamics which are already compromised by heart failure. Physical activity then decreases, worsening muscle atrophy and dysfunction.

SUMMARY

Beyond the imperative of optimal pharmacological treatment of each disease, strategies to lessen ventilation (e.g., walking aids, oxygen, opiates and anxiolytics, and cardiopulmonary rehabilitation) and improve mechanics (heliox, noninvasive ventilation, and inspiratory muscle training) might mitigate the burden of this devastating symptom in advanced heart failure-COPD.

Inspiratory Muscle Training Potentiates the Beneficial Effects of Proportional Assisted Ventilation on Exertional Dyspnea and Exercise Tolerance in COPD: A Proof-of-Concept Randomized and Controlled Trial

During pulmonary rehabilitation, a subset of subjects with COPD requires adjunct therapy to achieve high-intensity training. Both noninvasive ventilation (NIV) and inspiratory muscle training (IMT) are available to assist these subjects. We aimed to prime the respiratory muscles before NIV with IMT, anticipating additive effects for maximal exercise tolerance (T _lim) and dyspnea/leg fatigue relief throughout the exercise as primary outcomes. Changes in the respiratory pattern were secondary outcomes. COPD subjects performed a total of four identical constant work rate tests on a cycle ergometer at 75% of maximum work rate, under control ventilation (SHAM, 4 cm H₂O) or proportional assisted ventilation (PAV, individually adjusted), before and after 10 sessions of high-intensity IMT (three times/week) during 30 days. Two-way RM ANOVA with appropriate corrections were performed. Final analysis in nine subjects showed improved T _lim (Δ = 111 s) and lower minute-ventilation (Δ = 4 L^.min^-1) at exhaustion, when comparing the IMT effects within the PAV modality (p = 0.001 and p = 0.036, respectively) and improved T _lim for PAV vs. SHAM (PAV main-effect, p = 0.001; IMT main-effect, p = 0.006; PAV vs. IMT interaction, p = 0.034). In addition, IMT + PAV association, compared to PAV alone, resulted in lower respiratory frequency (IMT main-effect, p = 0.009; time main-effect, p < 0.0001; IMT vs. time interaction, p = 0.242) and lower inspiratory time related to duty cycle (IMT main-effect, p = 0.018; time main-effect, p = 0.0001; IMT vs. time interaction, p = 0.004) throughout exercise. The addition of IMT prior to a PAV-supported aerobic bout potentiates exercise tolerance and dyspnea relief and induces favourable changes in ventilatory pattern in severe COPD during high-intensity training (Brazilian Registry of Clinical Trials, number RBR-6n3dzz).

[Assessment of the respiratory muscles strength at patients with chronic obstructive pulmonary disease with various forms of comorbidity]

The respiratory muscles (RM) strength is the main indicator of their functional state. However, RM strength is not used as criteria for chronic obstructive pulmonary disease (COPD) stratification.

AIM

To evaluate the RM power of COPD patients with various variants of comorbidity and to determine the role of comorbidity in the development of respiratory muscle dysfunction.

MATERIALS AND METHODS

RM strength of 64 men with exacerbation of COPD was studied. The severity of comorbidity was assessed by the Charlson index. Depending on the prevalence of comorbidity, patients were divided into 3 groups: cardiovascular, cerebrovascular and metabolic. Maximum inspiratory (MIP) and expiratory (MEP) pressures in the oral cavity, maximum rate of pressure development (MRPD), sniff nasal inspiratory pressure (SNIP), MEP/MIP and SNIP/MIP indexes were determined with MicroRPM device (UK). Measured values of MIP, MEP and SNIP were compared with the proper ones. The most noticeable decrease of RM strength was defined in the group of patients with severe comorbidity.

RESULTS

In case of a mild comorbidity MEP and SNIP values were 68 and 78% of the predicted values and MIP value corresponded to the personified standard. RM strength of patients with COPD depended on the clinical variant of comorbidity. Thus, in the group of patients with cardiovascular variant of comorbidity auxiliary inspiratory muscles strength decreased. In the group of patients with cerebrovascular variant of comorbidity the expiratory muscles dysfunction predominated. In the group of patients with metabolic variant of comorbidity diaphragm dysfunction predominated.

CONCLUSION

The pathogenetic significance of various factors of COPD comorbidity in the development of RM dysfunction was confirmed by the results of the correlation analysis.

Community-dwelling individuals with stroke, who have inspiratory muscle weakness, report greater dyspnea and worse quality of life

The objective of the present study was to investigate if different levels of inspiratory muscle strength would be associated with dyspnea, walking capacity, and quality of life after stroke. For this exploratory study, the dependent outcome was strength of the inspiratory muscles, measured by maximal inspiratory pressure. Individuals with maximal inspiratory pressure ≥80 cmH2O were classified as non-weak, those with maximal inspiratory pressure between 45 and 80 cmH2O were classified as weak, and those with maximal inspiratory pressure ≤45 cmH2O were classified as very weak. Related outcomes included dyspnea, measured by the modified Medical Research Council scale; walking capacity, measured by the 6-minute walk test; and quality of life, measured by the Stroke-Specific Quality of Life scale. Fifty-three participants, who had a mean age of 62 years (SD 12) and a mean time since the onset of the stroke of 20 (SD 17) months were included. Significant differences were found only between the weak/very weak and non-weak groups. The mean differences between the non-weak and weak/very weak participants were -1.8 points (95% confidence interval -2.7 to -0.9) for dyspnea and 55 points (95% confidence interval 22-88) for quality of life. Significant correlations were found between measures of inspiratory strength and dyspnea (r = -0.54; P < 0.01) and quality of life (r = 0.56; P < 0.01). There were not found any significant differences or correlations regarding walking capacity. The findings demonstrated that individuals with stroke, who had weakness of the inspiratory muscles, reported greater dyspnea and worse quality of life, compared with those, who did not have weakness. The results regarding walking capacity remain unclear.

Exercise Training Modalities for People with Chronic Obstructive Pulmonary Disease

Exercise training confers health benefits for people with chronic obstructive pulmonary disease (COPD). This article reviews the evidence for several exercise training modalities shown to be beneficial among individuals with COPD. These modalities include aerobic, resistance, nonlinear periodized, upper limb and balance training, as well as yoga, Tai Chi, inspiratory muscle training, whole body vibration training and neuromuscular electrical stimulation. The literature pertaining to each modality was critically reviewed, and information on the rationale, mechanism(s) of action (where known), benefits, and exercise prescription is described to facilitate easy implementation into clinical practice.

Evaluation of isokinetic muscle strength of upper limb and the relationship with pulmonary function and respiratory muscle strength in stable COPD patients

Background

Upper limb muscle strength plays an important role in respiratory and pulmonary function, and limited research focuses on the role of strength and endurance of the elbow extensor and flexor. This study was conducted to accurately assess upper limb muscle function and quantified associations with pulmonary function and respiratory muscle strength in patients with stable chronic obstructive pulmonary disease (COPD).

Methods

In this cross-sectional study, patients with stable COPD treated in Yue-Yang Integrative Medicine Hospital from March 2014 to March 2016 were recruited. All participants underwent a pulmonary function test (forced expiratory volume in first second/forced vital capacity, FEV1/FVC; percentage value of predicted FEV1, FEV1%pred), a respiratory muscle strength test (maximal inspiratory pressure, MIP; maximal expiratory pressure, MEP), and an isokinetic test of dominant upper limb after a 24-hr interval (peak torque, PT; PT/body weight, PT/BW; total work, TW; endurance ratio, ER).

Results

A total of 88 patients with stable COPD (age: 65.5±8.7 years) were recruited, of which 73% (64 patients) were male. In the multiple stepwise regression analysis, sex remained as significant impactors in the final model for FEV1%pred (adjusted R²=0.243, P<0.001). Elbow flexor PT/BW and ER, sex, and BMI remained as significant impactors in the final model for FEV1/FVC (adjusted R²=0.255, P<0.01). Elbow flexor TW remained as significant impactors for MIP (adjusted R²=0.112, P=0.001), while elbow extensor PT and PT/BW and sex remained as significant impactors for MEP (adjusted R =0.385, P<0.01).

Conclusion

In stable COPD, pulmonary function and respiratory muscle strength are associated with upper limb muscle strength. In particular, elbow flexor endurance is likely an important impactor for pulmonary function and inspiratory muscle strength, while elbow extensor strength is of importance for expiratory muscle strength.

Handgrip strength measurement in patients with chronic obstructive pulmonary disease: Possible predictor of exercise capacity

BACKGROUND

Impaired exercise capacity is one of the most important prognostic factors for patients with chronic obstructive pulmonary disease (COPD). The 6-min walk test (6MWT) is a widely used method for assessing exercise capacity in patients with COPD. However, the 6MWT requires considerable effort from patients. Therefore, a less physically demanding, but also noninvasive, method is warranted. The objective of this study was to determine the predictors of the 6MWT distance (6MWD) in patients with COPD.

METHODS

This retrospective observational study enrolled 133 Japanese patients with COPD. All patients underwent the 6MWT, COPD assessment test (CAT), spirometry, respiratory muscle strength evaluation, body composition assessment, and handgrip strength (HGS) measurement. We examined the associations between the 6MWD and evaluated parameters.

RESULTS

From single regression analysis, the 6MWD was significantly correlated with age, CAT score, several spirometric measurements (e.g., percentages of forced vital capacity, forced expiratory volume in 1 s, and carbon monoxide diffusing capacity of the lungs [%DLCO]), respiratory muscle strength parameters (e.g., percentages of maximal expiratory and inspiratory pressures), skeletal muscle mass index, and HGS. In multiple regression analysis, age, CAT score, %DLCO, and HGS were independent predictors of the 6MWD. The %DLCO and HGS were strongly correlated as predictors of the 6MWD (p < 0.001).

CONCLUSIONS

We found that HGS was significantly correlated with the 6MWD compared with spirometric measurements or respiratory muscle strength parameters in Japanese patients with COPD, suggesting that HGS could be a simple and noninvasive predictor of the 6MWD in patients with COPD.

Inspiration for the Future: The Role of Inspiratory Muscle Training in Cystic Fibrosis

Cystic fibrosis (CF) is an inherited, multi-system, life-limiting disease characterized by a progressive decline in lung function, which accounts for the majority of CF-related morbidity and mortality. Inspiratory muscle training (IMT) has been proposed as a rehabilitative strategy to treat respiratory impairments associated with CF. However, despite evidence of therapeutic benefits in healthy and other clinical populations, the routine application of IMT in CF can neither be supported nor refuted due to the paucity of methodologically rigorous research. Specifically, the interpretation of available studies regarding the efficacy of IMT in CF is hampered by methodological threats to internal and external validity. As such, it is important to highlight the inherent risk of bias that differences in patient characteristics, IMT protocols, and outcome measurements present when synthesizing this literature prior to making final clinical judgments. Future studies are required to identify the characteristics of individuals who may respond to IMT and determine whether the controlled application of IMT can elicit meaningful improvements in physiological and patient-centered clinical outcomes. Given the equivocal evidence regarding its efficacy, IMT should be utilized on a case-by-case basis with sound clinical reasoning, rather than simply dismissed, until a rigorous evidence-based consensus has been reached.

The elevation training mask induces modest hypoxaemia but does not affect heart rate variability during cycling in healthy adults

This study examined the acute effects of the elevation training mask (ETM) on haemodynamics and heart rate variability (HRV) at rest, during cycling, and during recovery in healthy adults. Fifteen healthy male (N=9) and female (N=6) adults (27.0 ± 1.14 years) completed two trials with the mask (MASK) and without the mask (CON). The 40-minute cycling exercise protocol included 10-minute phases of (1) rest, (2) 50% of VO_2peak cycling, (3) 70% of VO_2peak cycling, and (4) recovery. Blood pressure and pulse oximetry saturation (S_PO₂) were measured at each phase. An Actiwave-Cardio ECG monitor (CamNtech, UK) was used to measure HRV variables including time and frequency domains. A greater response in systolic blood pressure (p=.035) was observed at rest while S_PO₂ (p=.033) was lower during high-intensity cycling (70% of VO_2peak) in the MASK trial. The HRV indices were not different between trials during cycling. However, heart rate (p=.047) was greater while inter-beat interval and sympathovagal balance (the ratio between low-frequency and high-frequency components; ln LF/HF, p=.01) were lower in the MASK than the CON trials during recovery. Wearing an ETM during high-intensity cycling (70% of VO_2peak) induces modest hypoxaemia. Although this device did not affect HRV changes during cycling, it seems to delay the cardiac-autonomic recovery from exercise. Healthy adults may be required to perform high-intensity exercise with an ETM to simulate a hypoxic environment, but future studies are needed to determine whether repeated exposure to this condition provides similar benefits as altitude training.

Current challenges in managing comorbid heart failure and COPD

INTRODUCTION

Heart failure (HF) with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) frequently coexist, particularly in the elderly. Given their rising prevalence and the contemporary trend to longer life expectancy, overlapping HF-COPD will become a major cause of morbidity and mortality in the next decade. Areas covered: Drawing on current clinical and physiological constructs, the consequences of negative cardiopulmonary interactions on the interpretation of pulmonary function and cardiopulmonary exercise tests in HF-COPD are discussed. Although those interactions may create challenges for the diagnosis and assessment of disease stability, they provide a valuable conceptual framework to rationalize HF-COPD treatment. The impact of COPD or HF on the pharmacological treatment of HF or COPD, respectively, is then comprehensively discussed. Authors finalize by outlining how the non-pharmacological treatment (i.e. rehabilitation and exercise reconditioning) can be tailored to the specific needs of patients with HF-COPD. Expert commentary: Randomized clinical trials testing the efficacy and safety of new medications for HF or COPD should include a sizeable fraction of patients with these coexistent pathologies. Multidisciplinary clinics involving cardiologists and respirologists trained in both diseases (with access to unified cardiorespiratory rehabilitation programs) are paramount to decrease the humanitarian and social burden of HF-COPD.

Effectiveness of water-based Liuzijue exercise on respiratory muscle strength and peripheral skeletal muscle function in patients with COPD

Objects

The purpose of this study was to quantitatively assess the effects of water-based Liuzijue exercise on patients with COPD and compare it with land-based Liuzijue exercise.

Materials and methods

Participants were randomly allocated to one of three groups: the water-based Liuzijue exercise group (WG), the land-based Liuzijue exercise group (LG), and the control group (CG). CG participants accepted no exercise intervention, while training groups performed Liuzijue exercise according to Health Qigong Liuzijue (People's Republic of China) in different environments for 60-min sessions twice a week for 3 months.

Results

Of the 50 patients enrolled, 45 (90%) completed the 3-month intervention. The CG showed decreased expiratory muscle strength, extensor and flexor endurance ratio (ER) of the elbow joints and flexor peak torque (PT), total work (TW), and ER of the knee joints (p<0.05). Both training groups showed improved respiratory muscle strength, which differed from the CG (p<0.001). In addition, extensor and flexor TW of the elbow joints in the training groups were increased (p<0.01), and the WG differed from the CG in extensor TW and ER and flexor TW (p<0.01), while the LG differed from the CG in flexor TW and extensor ER (p<0.05). PT, PT/body weight (BW), and TW in the knee joint extensor in the training groups were increased as well (PT and PT/BW: p<0.05, TW: p<0.01), and the WG differed from the CG in terms of knee joints outcomes, while the LG differed from the CG in flexor TW only (p<0.05).

Conclusion

Water-based Liuzijue exercise has beneficial effects on COPD patients' respiratory muscle strength and peripheral skeletal muscle function, and additional benefits may exist in endurance of upper limbs and strength and endurance of lower limbs when compared with land-based Liuzijue exercise.

Magnetic Stimulation Therapy in Patients with COPD: A Systematic Review

Magnetotherapy (MT) is a therapeutic treatment based on the use of magnetic fields (MF) that can have an anti-inflammatory and analgesic effect. MT represents a possible treatment or an ancillary therapeutic intervention for a wide range of diseases and it is often used in the field of physiotherapeutic practices. A crucial point in the treatment of chronic obstructive pulmonary disease (COPD) patients, to counteract muscular depletion and respiratory symptoms, is represented by physiotherapy. Nevertheless, the knowledge about the application of MF as a therapeutic option in COPD patients is very limited. The purpose of the present study was to define what is currently known about the use of MF in patients with COPD. A systematic review of the literature was conducted during the month of October 2017, searching three main databases. Only those citations providing detailed informations about the use of MF to treat COPD symptoms either during an acute or a chronic phase of the disease, were selected. Following the selection process three articles were included in the final analysis. The present review focused on a total of thirty-six patients with COPD, and on the effects of the application of MF. In the majority of cases, the treatment sessions with MF were carried-out in an outpatient setting, and they differed with regard to the duration; frequency of application; dosage; intensity of the applied MF. Basing on the available informations, it seems that MF is a feasible, well tolerated, safe therapeutic option, for the treatment of motor-related COPD symptoms.