Effects of a simple prototype respiratory muscle trainer on respiratory muscle strength, quality of life and dyspnea, and oxidative stress in COPD patients: a preliminary study

Deep learning-based respiratory muscle segmentation as a potential imaging biomarker for respiratory function assessment

Respiratory diseases significantly affect respiratory function, making them a considerable contributor to global mortality. The respiratory muscles play an important role in disease prognosis; as such, quantitative analysis of the respiratory muscles is crucial to assess the status of the respiratory system and the quality of life in patients. In this study, we aimed to develop an automated approach for the segmentation and classification of three types of respiratory muscles from computed tomography (CT) images using artificial intelligence. With a dataset of approximately 600,000 thoracic CT images from 3,200 individuals, we trained the model using the Attention U-Net architecture, optimized for detailed and focused segmentation. Subsequently, we calculated the volumes and densities from the muscle masks segmented by our model and performed correlation analysis with pulmonary function test (PFT) parameters. The segmentation models for muscle tissue and respiratory muscles obtained dice scores of 0.9823 and 0.9688, respectively. The classification model, achieving a generalized dice score of 0.9900, also demonstrated high accuracy in classifying thoracic region muscle types, as evidenced by its F1 scores: 0.9793 for the pectoralis muscle, 0.9975 for the erector spinae muscle, and 0.9839 for the intercostal muscle. In the correlation analysis, the volume of the respiratory muscles showed a strong correlation with PFT parameters, suggesting that respiratory muscle volume may serve as a potential novel biomarker for respiratory function. Although muscle density showed a weaker correlation with the PFT parameters, it has a potential significance in medical research.

The effect of cognition in combination with an ACBT on dyspnea-related kinesiophobia in patients with moderate to severe COPD: Quasirandomized controlled trial study

Patients with moderate to severe COPD frequently experience dyspnea, which causes these patients to acquire a fear of dyspnea and a fear of activity. This study developed a cognitive intervention combined with active cycle of breathing technique (ACBT) intervention program based on the fear-avoidance model, with the goal of evaluating the program's effectiveness in improving dyspnea-related kinesiophobia in patients with moderate to severe COPD. This study had a total of 106 participants. For 8 weeks, the intervention group (N=53) received cognitive combined with ACBT, while the control group (N=53) received standard care. The findings of the four times the dyspnea belief questionnaire were collected indicated that the combined intervention had a better impact on reducing dyspnea-related kinesiophobia than did routine nursing (P<0.05), and the impact persisted even after the intervention. Additionally, it may enhance dyspnea and quality of life, increase exercise capacity, and lower the BODE index.

The short- and long-term effects of lower limb endurance training on outpatients with chronic obstructive pulmonary disease

OBJECTIVE

To explore the short- and long-term effects of lower-limb endurance training on chronic obstructive pulmonary disease outpatients.

DESIGN

Prospective quasi-experimental study.

SETTING

1383-bed teaching hospital in Taiwan.

PARTICIPANTS

Overall, 69 outpatients diagnosed with chronic obstructive pulmonary disease were enrolled. A total of 60 patients completed the study.

INTERVENTION

Training group: Lower-limb endurance training; control group: Education only.

MAIN MEASURES

The modified medical research council score, chronic obstructive pulmonary disease assessment test score, pulmonary function test, and number of acute exacerbation within a year.

RESULTS

The training group showed significant improvement in the chronic obstructive pulmonary disease assessment test total score, modified medical research council score (both P < 0.001) at third month sustaining to 12th month (P < 0.001) and presented less events of acute exacerbation (P = 0.011) at 12th month. The chronic obstructive pulmonary disease assessment test decreased by 8 points sustaining to 12th month. The training group presented significant post-training functional capacity improvements in 6-min walking distance, lowest oxygen saturation during 6-min walking test, peak workload, maximum inspiratory/ expiratory pressures, and calf circumference.

CONCLUSIONS

The lower-limb endurance training improved perceived dyspnea in daily activity and health status after completion of training and sustaining for a year. The lower-limb endurance training alleviated disease impacted on reduced acute exacerbations.

Effect of breathing exercises on oxidative stress biomarkers in humans: A systematic review and meta-analysis

Background

Breathing exercises improve oxidative stress in healthy young adults and patients with diabetes, hypertension, and chronic obstructive pulmonary disease. Furthermore, the mechanism of respiratory intervention is controversial. Therefore, in this meta-analysis, we aimed to systematically evaluate the effects of breathing exercises on oxidative stress biomarkers in humans and provide evidence for the clinical application of breathing exercises.

Methods

The Embase, PubMed, Cochrane Library, Web of Science, CNKI, and WANFANG databases were searched for studies about the effects of breathing exercises on human oxidative stress levels, with no restraints regarding time, race, or language. The experimental group included various breathing exercises, and the outcome index included malondialdehyde, superoxide dismutase, and glutathione, nitric oxide, vitamin C, or total antioxidant capacity levels from a randomized controlled trial. Data were extracted by more than two authors and reviewed by one author.

Results

Ten studies were included from five countries. Data from patients with no disease, chronic obstructive pulmonary disease, hypertension, or diabetes were included. Participants who performed breathing exercises had greater changes in the included biomarkers than those who did not, suggesting that these biomarkers can be used to evaluate oxidative stress after respiratory interventions.

Conclusion

Breathing exercises increased SOD and GSH activities and decreased MDA content.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022337119, identifier CRD42022337119.

Inspiratory muscle training, with or without concomitant pulmonary rehabilitation, for chronic obstructive pulmonary disease (COPD)

BACKGROUND

Inspiratory muscle training (IMT) aims to improve respiratory muscle strength and endurance. Clinical trials used various training protocols, devices and respiratory measurements to check the effectiveness of this intervention. The current guidelines reported a possible advantage of IMT, particularly in people with respiratory muscle weakness. However, it remains unclear to what extent IMT is clinically beneficial, especially when associated with pulmonary rehabilitation (PR).   OBJECTIVES: To assess the effect of inspiratory muscle training (IMT) on chronic obstructive pulmonary disease (COPD), as a stand-alone intervention and when combined with pulmonary rehabilitation (PR).

SEARCH METHODS

We searched the Cochrane Airways trials register, CENTRAL, MEDLINE, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL) EBSCO, Physiotherapy Evidence Database (PEDro) ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform on 20 October 2021. We also checked reference lists of all primary studies and review articles.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared IMT in combination with PR versus PR alone and IMT versus control/sham. We included different types of IMT irrespective of the mode of delivery. We excluded trials that used resistive devices without controlling the breathing pattern or a training load of less than 30% of maximal inspiratory pressure (PImax), or both.

DATA COLLECTION AND ANALYSIS

We used standard methods recommended by Cochrane including assessment of risk of bias with RoB 2. Our primary outcomes were dyspnea, functional exercise capacity and health-related quality of life.  MAIN RESULTS: We included 55 RCTs in this review. Both IMT and PR protocols varied significantly across the trials, especially in training duration, loads, devices, number/ frequency of sessions and the PR programs. Only eight trials were at low risk of bias. PR+IMT versus PR We included 22 trials (1446 participants) in this comparison. Based on a minimal clinically important difference (MCID) of -1 unit, we did not find an improvement in dyspnea assessed with the Borg scale at submaximal exercise capacity (mean difference (MD) 0.19, 95% confidence interval (CI) -0.42 to 0.79; 2 RCTs, 202 participants; moderate-certainty evidence).   We also found no improvement in dyspnea assessed with themodified Medical Research Council dyspnea scale (mMRC) according to an MCID between -0.5 and -1 unit (MD -0.12, 95% CI -0.39 to 0.14; 2 RCTs, 204 participants; very low-certainty evidence).  Pooling evidence for the 6-minute walk distance (6MWD) showed an increase of 5.95 meters (95% CI -5.73 to 17.63; 12 RCTs, 1199 participants; very low-certainty evidence) and failed to reach the MCID of 26 meters. In subgroup analysis, we divided the RCTs according to the training duration and mean baseline PImax. The test for subgroup differences was not significant. Trials at low risk of bias (n = 3) demonstrated a larger effect estimate than the overall. The summary effect of the St George's Respiratory Questionnaire (SGRQ) revealed an overall total score below the MCID of 4 units (MD 0.13, 95% CI -0.93 to 1.20; 7 RCTs, 908 participants; low-certainty evidence).  The summary effect of COPD Assessment Test (CAT) did not show an improvement in the HRQoL (MD 0.13, 95% CI -0.80 to 1.06; 2 RCTs, 657 participants; very low-certainty evidence), according to an MCID of -1.6 units.  Pooling the RCTs that reported PImax showed an increase of 11.46 cmH₂O (95% CI 7.42 to 15.50; 17 RCTs, 1329 participants; moderate-certainty evidence) but failed to reach the MCID of 17.2 cmH₂O.  In subgroup analysis, we did not find a difference between different training durations and between studies judged with and without respiratory muscle weakness.  One abstract reported some adverse effects that were considered "minor and self-limited". IMT versus control/sham Thirty-seven RCTs with 1021 participants contributed to our second comparison. There was a trend towards an improvement when Borg was calculated at submaximal exercise capacity (MD -0.94, 95% CI -1.36 to -0.51; 6 RCTs, 144 participants; very low-certainty evidence). Only one trial was at a low risk of bias. Eight studies (nine arms) used the Baseline Dyspnea Index - Transition Dyspnea Index (BDI-TDI). Based on an MCID of +1 unit, they showed an improvement only with the 'total score' of the TDI (MD 2.98, 95% CI 2.07 to 3.89; 8 RCTs, 238 participants; very low-certainty evidence). We did not find a difference between studies classified as with and without respiratory muscle weakness. Only one trial was at low risk of bias. Four studies reported the mMRC, revealing a possible improvement in dyspnea in the IMT group (MD -0.59, 95% CI -0.76 to -0.43; 4 RCTs, 150 participants; low-certainty evidence). Two trials were at low risk of bias. Compared to control/sham, the MD in the 6MWD following IMT was 35.71 (95% CI 25.68 to 45.74; 16 RCTs, 501 participants; moderate-certainty evidence). Two studies were at low risk of bias. In subgroup analysis, we did not find a difference between different training durations and between studies judged with and without respiratory muscle weakness.  Six studies reported theSGRQ total score, showing a larger effect in the IMT group (MD -3.85, 95% CI -8.18 to 0.48; 6 RCTs, 182 participants; very low-certainty evidence). The lower limit of the 95% CI exceeded the MCID of -4 units. Only one study was at low risk of bias. There was an improvement in life quality with CAT (MD -2.97, 95% CI -3.85 to -2.10; 2 RCTs, 86 participants; moderate-certainty evidence). One trial was at low risk of bias. Thirty-two RCTs reported PImax, showing an improvement without reaching the MCID (MD 14.57 cmH₂O, 95% CI 9.85 to 19.29; 32 RCTs, 916 participants; low-certainty evidence). In subgroup analysis, we did not find a difference between different training durations and between studies judged with and without respiratory muscle weakness.   None of the included RCTs reported adverse events.

AUTHORS' CONCLUSIONS

IMT may not improve dyspnea, functional exercise capacity and life quality when associated with PR. However, IMT is likely to improve these outcomes when provided alone. For both interventions, a larger effect in participants with respiratory muscle weakness and with longer training durations is still to be confirmed.

The use of respiratory muscle training in patients with pulmonary dysfunction, internal diseases or central nervous system disorders: a systematic review with meta-analysis

OBJECTIVE

The aim of this systematic review with meta-analysis was to evaluate the effectiveness of RMT in internal and central nervous system disorders, on pulmonary function, exercise capacity and quality of life.

METHODS

The inclusion criteria were (1) publications designed as Randomized Controlled Trial (RCT), with (2) participants being adults with pulmonary dysfunction caused by an internal disease or central nervous system disorder, (3) an intervention defined as RMT (either IMT or EMT) and (4) with the assessment of exercise capacity, respiratory function and quality of life. For the methodological quality assessment of risk of bias, likewise statistical analysis and meta-analysis the RevMan version 5.3 software and the Cochrane Risk of Bias Tool were used. Two authors independently analysed the following databases for relevant research articles: PubMed, Scopus, Cochrane Library, Web of Science, and Embase.

RESULTS

From a total of 2200 records, the systematic review includes 29 RCT with an overall sample size of 1155 patients. Results suggest that patients with internal and central nervous system disorders who underwent RMT had better quality of life and improved significantly their performance in exercise capacity and in respiratory function assessed with FVC and MIP when compared to control conditions (i.e. no intervention, sham training, placebo or conventional treatments).

CONCLUSION

Respiratory muscle training seems to be more effective than control conditions (i.e. no intervention, sham training, placebo or conventional treatment), in patients with pulmonary dysfunction due to internal and central nervous system disorders, for quality of life, exercise capacity and respiratory function assessed with MIP and FVC, but not with FEV1.

Appropriate Timing and Type of Physical Training in Patients with COVID-19 for Muscle Health and Quality of Life: A Systematic Review

Physical activity is beneficial to modulate immune system function and has inverse relationship to ARDS linked with SARS-CoV-2. Physical activity consists of daily activity and physical training. Studies regarding effect of physical training on patients with COVID-19 are controversial. This systematic review aims to investigate physical training on muscle health and QOL in patients with COVID-19. The literature review was carried out using keywords: (Exercise) AND (COVID) AND (Muscle) AND (Observational Study) in several databases of PubMed and Cochrane Central Register of Controlled Trials (CENTRAL). All references were reviewed using critical appraisal Newcastle Ottawa Scale (NOS) and Centre for Evidence-Based Medicine (CEBM) checklist. The studies were subsequently screened for reporting exercise, muscle, and COVID-19. The descriptions of the extracted data are guided by Preferred Reporting Items for Systematic Reviews (PRISMA) statement with GRADE approach. This study is registered in PROSPERO: ID CRD42021295188. Six studies pooled and entered review synthesis. Studies were reviewed using critical appraisal by NOS and CEBM. Two clinical trial studies and four observational designs were selected. Our result showed physical training improved patients' outcomes in the acute phase, critical phase, and post-COVID-19 phase. Multiple types of physical trainings were suggested by those studies, and most of them showed beneficial effects to patients with COVID-19 in different phases. The level of evidence by GRADE was downgraded, and further investigations are needed to establish guidelines and strong recommendation for a specific stage of COVID-19.

Stimulation of both inspiratory and expiratory muscles versus diaphragm-only paradigm for rehabilitation in severe chronic obstructive pulmonary disease patients: a randomized controlled pilot study

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a progressive lung disease, might improve with neuromuscular electrical stimulation. No trials on inspiratory plus expiratory neuromuscular electrical stimulation have been conducted yet.

AIM

The aim of this study was to evaluate the safety and effectiveness of inspiratory plus expiratory neuromuscular electrical stimulation in subjects with severe COPD.

DESIGN

This was a multicenter, prospective, randomized controlled trial.

SETTING

The subjects were outpatients enrolled from Beijing Chao-Yang Hospital affiliated with Capital Medical University, Tianjin Chest Hospital, and the First Hospital of Hebei Medical University.

POPULATION

Subjects had stable COPD with severe respiratory impairment.

METHODS

Using a computer statistical software, 120 stable subjects were randomly allocated (1:1) to receive inspiratory plus expiratory neuromuscular electrical stimulation (study group) and diaphragm pacing (control group). Demographic and clinical data were collected before, and after 2, and 4 weeks of the trial. The intention-to-treat analysis was conducted. The primary outcome was to analyze the changes in functional exercise capacity, estimated as six-minute walk distance (6MWD), following electrical stimulation for 4 weeks. The secondary outcomes were changes in modified Medical Research Council score, forced expiratory volume in 1 second (FEV<inf>1</inf>), FEV<inf>1</inf>% predicted, and FEV<inf>1</inf> ratio forced vital capacity (FEV<inf>1</inf>/FVC) following electrical stimulation for 4 weeks.

RESULTS

The change in 6MWD was greater in the study group (65.53±39.45 m) than in the control group (26.66±32.65 m). The mean between-group difference at the fourth week was 29.07 m (95% confidence interval, 16.098-42.035; P<0.001). There were no significant between-group differences in the secondary outcomes after 4 weeks of electrical stimulation. For GOLD-4 COPD subjects, FEV<inf>1</inf> and FEV<inf>1</inf>/FVC improved in the study group (P<0.05). No electrical stimulation-related serious adverse events were observed in either group.

CONCLUSIONS

6MWD were increased significantly, without adverse events, after four weeks of treatment of inspiratory plus expiratory neuromuscular electrical stimulation in stable patients with severe COPD, suggesting that this protocol benefits COPD rehabilitation.

CLINICAL REHABILITATION IMPACT

The results of this study suggest that the simultaneous use of inspiratory plus expiratory neuromuscular electrical stimulation as an adjunct therapy may improve the functional exercise capacity of severe stable COPD subjects.

Effect of Pulmonary Rehabilitation for Patients With Post-COVID-19: A Systematic Review and Meta-Analysis

Background

Evidence increasingly suggested that impaired respiratory function remained in about 40% of patients with coronavirus disease 2019 (COVID-19) after discharge, jeopardizing their activities of daily living and quality of life (QoL) in a long term. Pulmonary rehabilitation (PR) can improve exercise capacity and QoL in individuals with chronic lung disease; however, evidence on the effect of PR for patients with post-COIVD-19 was scarce. This study aimed to conduct a systematic review and meta-analysis to evaluate the effect of PR on lung impairment for patients with post-COVID-19.

Methods

Five databases were searched for all the published trials of PR for patients with post-COVID-19 from 2019 to October 2021. Data were extracted using a standardized form. The risks of bias of included studies were assessed using the Cochrane risk of the bias assessment tool. Data were synthesized where possible; otherwise, qualitative analysis was done.

Results

Among 6,000 retrieved studies, 3 studies with 233 patients after COVID-19 were included. The pooled estimate of PR effect on 6-min walk test (6-MWT) (50.41, 95% CI 34.34 to 66.48; p < 0.0001) was in favor of the experiment group with clinical importance. It is found that PR could improve the symptom of dyspnea and QoL; however, its effect on pulmonary function test was inconsistent across studies. The risk of bias of included studies varied, with major concerns on the risk of blinding of participants and interventions performers.

Conclusion

The review showed that PR could improve exercise capacity measured by 6-MWT among patients with mild-to-moderate lung impairment after COVID-19. The interpretation of effects on lung function, dyspnea, and QoL should be cautious due to inadequate and conflicting data reported across studies.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021289562, identifier: CRD42021289562.

Oxidative Stress Markers in COPD Patients Admitted to Pulmonary Rehabilitation

Background:

Chronic obstructive pulmonary disease (COPD) is a pathology, which leads to an irreversible and progressive reduction of the airflow, usually caused by smoking, but only present in 25% of smokers. Some mechanisms involved in the onset and progression of the disease are local and systemic factors such as inflammation, exacerbated immune response and the appearance of oxidative stress. For all these reasons, the use of oxidative stress parameters as progression markers or even as a way to monitor the response of any kind of non-pharmacological interventions, like the use of pulmonary rehabilitation (PR), is feasible.

Aims:

The study aims to determine markers of oxidative stress levels in plasma and erythrocytes in patients with COPD through the application of a PR protocol.

Methods:

The study included 25 patients diagnosed with COPD according to the GOLD criteria with a medical indication of PR and attendance at the gym in San José Hospital, Santiago, Chile. Blood samples were obtained before the start of the protocol, in the 10th session, and at the end of the protocol (20th session). These samples were stored for oxidative stress determinations: FRAP (ferric reducing ability of plasma), F2-isoprostanes, reduced (GSH)/oxidized (GSSG) ratio and antioxidant enzyme activity in the erythrocyte. In all stages, associations between events and clinical parameters in patients have been observed. The clinical parameters assessed were the six-minute walking test (6MWT), maximal inspiratory and expiratory pressure, the BODE index and Saint George’s respiratory questionnaire, which includes quality of life.

Results:

The intracellular and extracellular capacity (GSH/GSSG and FRAP) in patients in PR at the 10th session were 53.1 and 34% higher than basal values, respectively. Only the GSH/GSSG ratio was 38.2% lower at the 20th session, related in part with higher plasma and erythrocyte lipid peroxidation at baseline. This could be due to the high concentration of reactive oxygen species in the first sessions, which has been reported in the literature as the acute effect of controlled exercise. Blood lipid peroxidation was 43.34 and 58.34% lower at the 10th and 20th sessions, respectively, demonstrating the improvements in the oxidative parameters with long-term exercise. With respect to oxidative enzyme activity, superoxide dismutase and catalase showed higher values of activity at the 10th and 20th sessions compared to the baseline. In the clinical parameters of the PR, significant changes were found in the BODE index and Saint George’s questionnaire, with these results being associated with a less predictive mortality score and a better understanding of the disease. This may be because the patients achieved longer distances in the 6MWT and better understood the disease at the end of the PR.

Conclusion:

The goal of this study was to contribute to the pathophysiological basis for further research on COPD patients, a disease of high prevalence in Chile. This study could support the basis for non-pharmacological strategies such a PR.

Effect of inspiratory muscle training on dyspnea-related kinesiophobia in chronic obstructive pulmonary disease: A randomized controlled trial

BACKGROUND

The major symptom of chronic obstructive pulmonary disease (COPD) is dyspnea, which causes dyspnea-related kinesiophobia resulting in avoidance of activities associated with dyspnea or compensation by reducing the rate of activity. The aim of this study was to assess dyspnea-related kinesiophobia and determine the effect of inspiratory muscle training (IMT) on dyspnea-related kinesiophobia in COPD.

METHODS

Forty COPD subjects were randomly allocated to either the IMT or sham group. Both groups' maximal inspiratory pressure (MIP) was assessed weekly. All patients were instructed to perform the training exercises for 15 min twice a day, 5 days a week for a total of 8 weeks. In the IMT group, intensity was set at 30% of MIP and adjusted according to weekly MIP value. In the sham group, intensity remained constant at 15% of initial MIP. Pulmonary function test (PFT), respiratory muscle strength, 6-min walk test (6 MWT), Breathlessness Beliefs Questionnaire (BBQ), Modified Medical Research Council scale (MMRC), modified Borg scale, Hospital Anxiety and Depression Scale (HADS), Saint George's Respiratory Questionnaire (SGRQ), and COPD Assessment Test (CAT) were assessed before and after the intervention.

RESULTS

BBQ scores ranged from 18 to 51, with mean values in the IMT and sham groups of 39.80 ± 7.62 and 43.00 ± 6.58, respectively. When between-group differences of all outcome scores were compared, there was a statistically significant improvement in the IMT group than in the sham group (p < 0.05). After IMT, statistically significant decreases in BBQ and modified Borg scores were observed in within groups (p ≤ 0.001). These decreases were significantly greater in the IMT group (p ≤ 0.001). MMRC decreased significantly only in the IMT group (p < 0.001). There was a statistically significant increase in PFT values in the IMT group (p = 0.007-0.045), but no difference in the sham group (p = 0.129-0.886). Both groups showed statistically significant improvement in respiratory muscle strength, 6 MWT distance, and CAT score after 8 weeks (p < 0.05). All HADS and SGRQ scores decreased significantly in the IMT group (p < 0.001), whereas only the SGRQ activity score decreased significantly in the sham group (p = 0.017).

CONCLUSIONS

Our study provides data on the presence and level of dyspnea-related kinesiophobia in COPD patients. All patients had BBQ scores higher than 11, indicating dyspnea-related kinesiophobia. IMT reduced BBQ score and improved respiratory function, and exercise capacity. Our results also support the other known benefits of IMT such as reduced dyspnea and symptom perception, decreased anxiety and depression, and improved quality of life.

Inspiratory muscle training for recovered COVID-19 patients after weaning from mechanical ventilation: A pilot control clinical study

BACKGROUND

To the best of our knowledge, no studies have evaluated the effects of inspiratory muscle training (IMT) on recovered COVID-19 patients after weaning from mechanical ventilation. Therefore, this study assessed the efficacy of IMT on recovered COVID-19 patients following mechanical ventilation.

METHODS

Forty-two recovered COVID-19 patients (33 men and 9 women) weaned from mechanical ventilation with a mean age of 48.05 ± 8.85 years were enrolled in this pilot control clinical study. Twenty-one patients were equipped to 2-week IMT (IMT group) and 21 matched peers were recruited as a control (control group). Forced vital capacity (FVC%), forced expiratory volume in 1 second (FEV1%), dyspnea severity index (DSI), quality of life (QOL), and six-minute walk test (6-MWT) were assessed initially before starting the study intervention and immediately after intervention.

RESULTS

Significant interaction effects were observed in the IMT when compared to control group, FVC% (F = 5.31, P = .041, ηP2 = 0.13), FEV1% (F = 4.91, P = .043, ηP2 = 0.12), DSI (F = 4.56, P = .032, ηP2 = 0.15), QOL (F = 6.14, P = .021, ηP2 = 0.17), and 6-MWT (F = 9.34, P = .028, ηP2 = 0.16). Within-group analysis showed a significant improvement in the IMT group (FVC%, P = .047, FEV1%, P = .039, DSI, P = .001, QOL, P < .001, and 6-MWT, P < .001), whereas the control group displayed nonsignificant changes (P > .05).

CONCLUSIONS

A 2-week IMT improves pulmonary functions, dyspnea, functional performance, and QOL in recovered intensive care unit (ICU) COVID-19 patients after consecutive weaning from mechanical ventilation. IMT program should be encouraged in the COVID-19 management protocol, specifically with ICU patients.

Breathing exercises in people with COPD: A realist review

AIMS

To determine the theoretical framework that explains the mechanisms of the success of breathing exercise interventions in people with chronic obstructive pulmonary disease.

DESIGN

A realist review.

DATA SOURCES

Seven bibliographic databases and the grey literature were searched from 2015-January 2020 to identify the studies of breathing exercises.

REVIEW METHODS

The evaluation criteria of realist review and the mixed method appraisal tool were both used to evaluate the included studies. We extracted and integrated the context-mechanism-outcome strings of each study to form the theoretical framework.

RESULTS

Six theoretical mechanisms that affected the success of the intervention were articulated: Wide acceptance of training methods, Integration of the intervention with life, Self-management of the participants, Confidence in controlling symptoms, Participation and support of practitioners, Motivation for intervention. Conversely, the other two mechanisms including the gap between implementation and training and the duration of the intervention, had negative impacts on the implementation of breathing exercises.

CONCLUSION

This review updates and expands the previous literature review on the impact of breathing exercises in people and provides researchers and clinical practitioners with theoretical mechanisms to ensure that the interventions achieve expected effects.

IMPACT

When formulating or selecting breathing exercise interventions, our theoretical framework will guide researchers and clinical practitioners to ensure that the intervention will have practical effects.

Muscle metabolomics analysis reveals potential biomarkers of exercise‑dependent improvement of the diaphragm function in chronic obstructive pulmonary disease

Decreased diaphragm function is a crucial factor leading to reduced ventilatory efficiency and worsening of quality of life in chronic obstructive pulmonary disease (COPD). Exercise training has been demonstrated to effectively improve the function of the diaphragm. However, the mechanism of this process has not been identified. The emergence of metabolomics has allowed the exploration of new ideas. The present study aimed to analyze the potential biomarkers of exercise-dependent enhancement of diaphragm function in COPD using metabolomics. Sprague Dawley rats were divided into three groups: COPD + exercise group (CEG); COPD model group (CMG); and control group (CG). The first two groups were exposed to cigarette smoke for 16 weeks to establish a COPD model. Then, the rats in the CEG underwent aerobic exercise training for 9 weeks. Following confirmation that exercise effectively improved the diaphragm function, a gas chromatography tandem time-of-flight mass spectrometry analysis system was used to detect the differential metabolites and associated pathways in the diaphragm muscles of the different groups. Following exercise intervention, the pulmonary function and diaphragm contractility of the CEG rats were significantly improved compared with those of the CMG rats. A total of 36 different metabolites were identified in the comparison between the CMG and the CG. Pathway enrichment analysis indicated that these different metabolites were involved in 17 pathways. A total of 29 different metabolites were identified in the comparison between the CMG and the CEG, which are involved in 14 pathways. Candidate biomarkers were selected, and the pathways analysis of these metabolites demonstrated that 2 types of metabolic pathways, the nicotinic acid and nicotinamide metabolism and arginine and proline metabolism pathways, were associated with exercise-induced pulmonary rehabilitation.

Methodologies of inspiratory muscle training techniques in obstructive lung diseases

Background: Inspiratory muscle training (IMT) is a non-pharmacological, non-invasive therapeutic method that can improve the quality of life in patients with obstructive lung diseases. The effectiveness of IMT may depends on the type of the device used in the training and the parameters of the training programme. Objectives: The aim of the review was to present different techniques and protocols of IMT used in patients with obstructive lung diseases. Methods: The MEDLINE and EMBASE were searched to identify the potentially eligible publications from the previous 5 years. The various protocols of IMT used in different studies were analysed and described in detail. Results: A database search identified 333 records, of which 22 were included into the final analysis. All of the finally analysed studies were conducted in patients with chronic obstructive pulmonary disease (COPD). The protocols of IMT used in the studies differed in the type of the device used, the duration of the training programme, the number and the duration of training sessions, the initial load, and the rate at which the load was changed during the training. Conclusions: IMT is used mainly in studies on patients with COPD and not with asthma. There is no one approved training programme for IMT. The most predominant type of IMT is a training with threshold loading. The most frequently used devices for IMT are POWERbreath and Threshold IMT. The protocols of IMT used in the studies are very diverse.

Preliminary study: comparative effects of lung volume therapy between slow and fast deep-breathing techniques on pulmonary function, respiratory muscle strength, oxidative stress, cytokines, 6-minute walking distance, and quality of life in persons with COPD

BACKGROUND

Lung volume therapy with the Voldyne® device can improve lung volume and has a nonsignificant benefit on respiratory muscle strength via the slow deep-breathing technique (SDBT); whereas respiratory muscle training with a respiratory muscle trainer via the fast deep-breathing technique (FDBT) has produced a significant improvement in people with COPD. Thus, the aim of this study was to compare the efficiency of lung volume therapy with the Voldyne® device with the SDBT and FDBT on pulmonary function, respiratory muscle strength, oxidative stress, cytokines, walking capacity, and quality of life (QoL) in people with COPD.

METHODS

A total of 30 COPD patient volunteers with mild (stage I) to moderate (stage II) severity were randomized into two groups: SDBT (n=15) and FDBT (n=15). Pulmonary function (FVC, FEV1, and FEV1/FVC), maximal inspiratory mouth pressure (PImax), oxidative stress status (total antioxidant capacity [TAC], glutathione [GSH], malondialdehyde [MDA], and nitric oxide [NO]), inflammatory cytokines (tumor necrosis factor-alpha [TNF-α] and IL-6), 6-minute walking distance (6MWD), and total clinical COPD questionnaire (CCQ) score were evaluated before and after 4 weeks of training.

RESULTS

All the parameters had no statistical difference between the groups before training. The PImax, TAC, IL-6, total QoL score, and 6MWD changed significantly in the SDBT group after the 4-week experiment as compared to those in the pre-experimental period, whereas FVC, FEV1, FEV1%, FEV1/FVC%, PImax, TAC, MDA, NO, TNF-α, IL-6, 6MWD, and total CCQ score changed significantly in the FDBT group as compared to those in the pre-experimental period. The FEV1%, PImax, TNF-α, IL-6, and total CCQ score differed significantly in the FDBT group in the post-experimental period as compared to those in the SDBT group.

CONCLUSION

This preliminary study concluded that the application of incentive spirometry with the Voldyne® device via fast deep breathing possibly improved respiratory muscle strength and QoL and reduced inflammatory cytokines, MDA, and NO better than that via slow deep breathing among people with COPD.

Comparative study of two different respiratory training protocols in elderly patients with chronic obstructive pulmonary disease

Aim

The aim of the present study was to compare threshold inspiratory muscle training (IMT) and expiratory muscle training (EMT) in elderly male patients with moderate degree of COPD.

Materials and methods

Forty male patients with moderate degree of COPD were recruited for this study. They were randomly divided into two groups: the IMT group who received inspiratory training with an intensity ranging from 15% to 60% of their maximal inspiratory pressure, and the EMT group who received expiratory training with an equal intensity which was adjusted according to the maximal expiratory pressure. Both groups received training three times per week for 2 months, in addition to their prescribed medications.

Results

Both IMT and EMT groups showed a significant improvement in forced vital capacity, forced expiratory volume in the first second, forced expiratory volume in the first second% from the predicted values, and forced vital capacity% from the predicted value, with no difference between the groups. Both types of training resulted in a significant improvement in blood gases (SaO₂%, PaO₂, PaCO₂, and HCO₃), with the inspiratory muscle group showing the best results. Both groups showed a significant improvement in the 6-min walking distance: an increase of about 25% in the inspiratory muscle group and about 2.5% in the expiratory muscle group.

Conclusion

Both IMT and EMT must be implemented in pulmonary rehabilitation programs in order to achieve improvements in pulmonary function test, respiratory muscle strength, blood oxygenation, and 6-min walking distance.