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.

Investigation of Inspiratory Muscle Training Efficiency Before Bronchoscopic Lung Volume Reduction: A Randomized Controlled Trial

INTRODUCTION

Pulmonary rehabilitation (PR) is recommended prior to bronchoscopic lung volume reduction (BLVR) procedures to optimize patient outcomes. However, there's a lack of clear guidance on PR content. The aim of our study is to examine the effect of adding inspiratory muscle training (IMT) to standard PR before BLVR on exercise capacity, dyspnea, fatigue level and quality of life.

METHODS

Sixty-four patients were randomly assigned to either the PR Group (PRGr) or the PR with IMT group (IMTGr). Both groups underwent an 8-week standard PR program, including breathing exercises, muscle strengthening, and walking. Additionally, IMTGr received IMT sessions. Outcome measures comprised six-minute walking distance (6MWD), maximal inspiratory and expiratory pressures (MIP, MEP), peripheral muscle strength, modified Medical Research Council dyspnea score, fatigue symptom scale, spirometric parameters, Saint George Quality of Life Questionnaire (SGRQ), International Physical Activity Questionnaire Short Form (IPAQ-SF), and Hospital Anxiety and Depression Scale.

RESULTS

Our study found no significant difference in exercise capacity improvement between IMTGr and PRGr. However, IMTGr showed significant improvement in MIP compared to PRGr. Both groups experienced improvements in dyspnea, fatigue, and depression scores, as well as enhancements in 6MWD, MEP, peripheral muscle strength, IPAQ-SF and SGRQ scores.

CONCLUSION

Adding IMT to PR did not show a significant difference between groups among BLVR-eligible patients. However, improved respiratory muscle strength may have positive clinical implications. Further research is needed to explore short and long-term effects.

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.

Determination of the minimal important difference for inspiratory muscle strength in people with severe and very severe COPD

OBJECTIVE

Inspiratory muscle training is recommended for people with chronic obstructive pulmonary disease (COPD) with inspiratory muscle weakness. Clinical interpretation of changes in inspiratory muscle strength could be helped by the determination of cut-off values. The aim of this study was to estimate the minimal important difference for inspiratory muscle strength assessed with maximal inspiratory pressure (MIP) in people with COPD.

DESIGN

Post hoc analysis of a randomized controlled trial (EMI2 study) including people with severe to very severe COPD undergoing a pulmonary rehabilitation program was conducted. The determination of the minimal important difference was realized using both anchor-based and distribution-based methods.

SETTING

The study includes patients admitted to the rehabilitation program unit of the Centre Hospitalier des Pays de Morlaix (Morlaix, France) between March 5, 2014 and September 8, 2016.

PARTICIPANTS

Seventy-three people with severe to very severe COPD (age 62.2  ±  8.0 years, forced expiratory volume in 1 s 36.4  ±  9.5% of theoretical) were analyzed.

INTERVENTION

Patients followed a standardized pulmonary rehabilitation program 5 days a week for 4 weeks. The program included aerobic training, ground-based outdoor walking training, and strengthening of lower and upper limb muscles.

MAIN MEASURES

At the end of the pulmonary rehabilitation program, MIP improved by 14.8  ±  14.9 cmH2O (p < 0.05). Regarding the anchor-based method, only the modified Medical Research Council was selected as an appropriate anchor. The receiver operating characteristic curve analysis reported a minimal important difference of 13.5 cmH2O (sensibility: 75% specificity: 67.5%). Using distribution-based methods, the estimate of minimal important difference was 7.9 cmH2O (standard error of measurement method) and 10.9 cmH2O (size effect method).

RESULTS

The estimations proposed by this study ranged from 7.9 to 13.5 cmH2O.

CONCLUSIONS

The measurement of minimal important difference is a simple tool for assessing the changes of inspiratory muscle strength during a pulmonary rehabilitation program. We propose a minimal important difference of 13.5 cmH2O for the improvement of MIP. Further studies are needed to confirm this estimation.ClinicalTrials.gov identifier: NCT02074813.

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.

Does inspiratory muscle training provide additional benefits during pulmonary rehabilitation in people with interstitial lung disease? A randomized control trial

BACKGROUND

Interstitial lung disease (ILD) encompasses a diverse group of chronic lung conditions which is often characterized by inspiratory muscle weakness (IMW). Despite the potential importance of inspiratory muscle dysfunction in ILD, the effect of inspiratory muscle training (IMT) added to pulmonary rehabilitation (PR) in ILD largely remains unknown.

OBJECTIVE

The primary objective of the present study was to evaluate the benefits of IMT added to PR on inspiratory muscle strength and secondary objectives were to assess its effects on functional capacity, health-related quality of life (HRQoL), pulmonary function test (PFT) and dyspnea in ILD along with IMW.

METHODS

Fifty-one participants were randomly allocated into two groups; PR + IMT (n = 26) or PR alone (n = 25). The primary outcome [maximal inspiratory pressure (PI_max)] and secondary outcomes [6-min walk distance (6MWD), St. George's Respiratory Questionnaire (SGRQ), PFT and modified Medical Research Council dyspnea scale (mMRC)] were evaluated before and after the 8-weeks intervention. Independent t-test or Mann Whitney-U test was applied for between-group comparisons while for within-group comparison Wilcoxon's Sign Rank test or paired t test was performed.

RESULTS

At the end of 8 weeks exercise intervention inspiratory muscle strength (PI_max + 11.10 cm H₂O, p< .001), functional capacity (6MWD, + 47.90 m, p= .001), HRQoL (SGRQ-total - 4 points, p= .038) and dyspnea (mMRC dyspnea scale, -1.27, p< .001) improved significantly in PR+IMT group alone.

CONCLUSION

Inclusion of IMT to PR may have superior benefits as compared to PR alone in ILD accompanied with IMW.

[The role of the physiotherapist in the assessment and management of dyspnea]

The role of the physiotherapist in the assessment and management of dyspnea. Dyspnea is the most common symptom in cardio-respiratory diseases. Recently improved comprehension of dyspnea mechanisms have underlined the need for three-faceted assessment. The three key aspects correspond to the "breathing, thinking, functioning" clinical model, which proposes a multidimensional - respiratory, emotional and functional - approach. Before initiating treatment, it is essential for several reasons to assess each specific case, determining the type of dyspnea affecting the patient, appraising the impact of shortness of breath, and estimating the effectiveness of the treatment applied. The physiotherapist has a major role to assume in the care of dyspneic patients, not only in assessment followed by treatment but also as a major collaborator in a multidisciplinary team, especially with regard to pulmonary rehabilitation. The aim of this review is to inventory the existing assessment tools and the possible physiotherapies for dyspnea, using a holistic approach designed to facilitate the choice of techniques and to improve quality of care by fully addressing the patient's needs.

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 Effect of Progressive Relaxation Exercises on Dyspnea and Anxiety Levels in Individuals With COPD: A Randomized Controlled Trial

Dyspnea is a common symptom and anxiety is a common comorbidity of chronic obstructive pulmonary disease (COPD). They affect individuals with COPD in a multifaceted way, causing many disabilities. Progressive relaxation exercises (PREs) are an important intervention in reducing symptoms and comorbidity. The aim of this study was to determine the effects of PREs on dyspnea and anxiety levels in individuals with COPD. A pretest-posttest randomized controlled trial was conducted at the chest diseases clinic of a university hospital in Turkey. Forty-four patients with COPD who met the inclusion criteria for participation in the study were assigned either to an intervention or a control group, with 22 patients in each group. In the intervention group, the patients performed PREs once a day for 4 weeks in addition to the standard treatment. The patients in the control group received the standard treatment. In the data collection stage of the study, questionnaire forms, namely, the Modified Borg Scale (MBS), Modified British Medical Research Council Dyspnea Scale, COPD Assessment Test (CAT), and Beck Anxiety Inventory (BAI), were used. Data were collected before (the first follow-up) and after the intervention (the second follow-up). In the second follow-up, the MBS, BAI, and CAT scores decreased significantly in the intervention group (P < .05) but showed no significant changes in the control group (P > .05). This study demonstrates that PREs can reduce dyspnea and anxiety levels in individuals with COPD.

Inspiratory Muscle Training in Patients with Chronic Obstructive Pulmonary Disease (COPD) as Part of a Respiratory Rehabilitation Program Implementation of Mechanical Devices: A Systematic Review

Chronic Obstructive Pulmonary Disease (COPD) is a complex and heterogeneous disease, with pulmonary and extrapulmonary manifestations, which leads to the need to personalize the assessment and treatment of these patients. The latest updates of national and international guidelines for the management of COPD reveal the importance of respiratory rehabilitation (RR) and its role in improving symptoms, quality of life, and psychosocial sphere of patients. Within RR, the inspiratory muscle training (IMT) has received special interest, showing benefits in maximum inspiratory pressure, perception of well-being, and health status in patients with chronic heart disease, respiratory diseases, and dyspnea during exercise. The aim of this review is to assess the efficacy of IMT in COPD patients through the use of inspiratory muscle training devices, compared with respiratory rehabilitation programs without inspiratory muscle training. In the last years, many mechanical devices focused on inspiratory muscle training have been developed, some of them, such as the AirOFit PRO™, PowerBreath®, or FeelBreathe®, have shown clear benefits. The active search for candidate patients to undergo the RR program with inspiratory muscle training using this type of device in COPD patients represents an advance in the treatment of this disease, with direct benefits on the quality of life of the patients. In this article, we review the available evidence on IMT in these patients and describe the different devices used for it.

Effectiveness of 12-week inspiratory muscle training with manual therapy in patients with COPD: A randomized controlled study

The benefits of inspiratory muscle training (IMT) in patients with COPD were reported. However, its effects are limited in severe COPD patients. Further researches are required in new and complementary modalities demonstrating IMT efficacy in severe COPD patients. This study aims to investigate effects of manual therapy (MT) additional over IMT on functional capacity, respiratory muscle strength, pulmonary function, dyspnea, fatigue, and quality of life in severe COPD patients. Sixty patients with COPD in GOLD stage III-IV were included in this prospective single-blind randomized trial. Patients were randomly assigned to receive either MT additional over IMT at 40% of maximal inspiratory pressure (MIP) (n = 30) or only IMT (n = 30) for 12 weeks. MT group received MT during 12 weeks for 30 min additional to IMT. Pulmonary function, respiratory muscle strength, functional capacity, dyspnea, fatigue, and quality of life were evaluated by spirometry, mouth pressure device, six-minute walk test, Modified Medical Research Council (mMRC) dyspnea scale, fatigue severity scale, and St. George's Respiratory Questionnaire (SGRQ), respectively. MT group had significantly greater improvement in FEV1%, FVC%, PEF%, respiratory muscle strength, function, dyspnea, fatigue, and quality of life compared with IMT group (p < 0.05). 6MWT (p < 0.001, effect size Cohen's d: 0.915), MIP (p < 0.001, effect size Cohen's d: 1.235), and mMRC score (p < 0.001, effect size Cohen's d: 0.982) were significantly improved in IMT with MT group. This study demonstrated that subjects in IMT with MT group had improved outcomes in functional capacity, respiratory muscle strength, pulmonary function, dyspnea, fatigue perception, and quality of life compared with alone IMT group.

Respiratory Muscle Training Can Improve Cognition, Lung Function, and Diaphragmatic Thickness Fraction in Male and Non-Obese Patients with Chronic Obstructive Pulmonary Disease: A Prospective Study

Patients with chronic obstructive pulmonary disease (COPD) are frequently comorbid with mild cognitive impairment (MCI). Whether respiratory muscle training (RMT) is helpful for patients with COPD comorbid MCI remains unclear. Inspiratory muscle training (IMT) with or without expiratory muscle training (EMT) was performed. Patients were randomly assigned to the full training group (EMT + IMT) or the simple training group (IMT only). A total of 49 patients completed the eight-week course of RMT training. RMT significantly improved the maximal inspiratory pressure (MIP), the diaphragmatic thickness fraction and excursion, lung function, scores in the COPD assessment test (CAT), modified Medical Research Council (mMRC) scale scores, and MMSE. The between-group difference in the full training and single training group was not significant. Subgroup analysis classified by the forced expiratory volume in one second (FEV1) level of patients showed no significant differences in MIP, lung function, cognitive function, and walking distance. However, a significant increase in diaphragmatic thickness was found in patients with FEV1 ≥ 30%. We suggest that patients with COPD should start RMT earlier in their disease course to improve physical activity.

The Effect of Inspiratory Muscle Training on the Pulmonary Function in Mixed Martial Arts and Kickboxing Athletes

Inspiratory muscle training (IMT) has found its way into athletes’ routine as a promising way of improving pulmonary function in combination with standard training. The objective of the study was to examine the effects of resistive IMT on the pulmonary function variables in athletes of two combat sports, i.e., mixed martial arts (MMA) and kickboxing. Fourteen kickboxing and 12 MMA male athletes qualified for the study. They were randomly assigned into experimental and control groups. While both groups participated in their standard training, the experimental group additionally participated in IMT which consisted of 30 breaths twice a day for 6 weeks. The pulmonary functions were measured at baseline and after 6 weeks of IMT. The addition of IMT to standard training increased significantly the forced expiratory volume in the first second to vital capacity ratio (FEV1/VC), and the maximum voluntary ventilation (MVV) (p < 0.05) with changes of 5.7%, and 28.6%, respectively, in MMA athletes. The kickboxing group showed no significant changes. The interaction of the sport discipline and IMT intervention yielded a strong significant change in the MVV (F(1, 11) = 14.53, p < 0.01), and FEV1/VC (F(1, 11) = 20.67, p < 0.01) to the benefit of MMA athletes in comparison with kickboxing athletes. Combining resistive IMT for 6 weeks with standard training was effective to improve some pulmonary functions in MMA athletes, but did not lead to additional gains in kickboxing athletes.

Dyspnoea-12 and Multidimensional Dyspnea Profile: Systematic Review of Use and Properties

CONTEXT

The Dyspnoea-12 (D-12) and Multidimensional Dyspnea Profile (MDP) were specifically developed for assessment of multiple sensations of breathlessness.

OBJECTIVES

This systematic review aimed to identify the use and measurement properties of the D-12 and MDP across populations, settings and languages.

METHODS

Electronic databases were searched for primary studies (2008-2020) reporting use of the D-12 or MDP in adults. Two independent reviewers completed screening and data extraction. Study and participant characteristics, instrument use, reported scores and minimal clinical important differences (MCID) were evaluated. Data on internal consistency (Cronbach's α) and test-retest reliability (intraclass correlation coefficient, ICC) were pooled using random effects models between settings and languages.

RESULTS

A total 75 publications reported use of D-12 (n = 35), MDP (n = 37) or both (n = 3), reflecting 16 chronic conditions. Synthesis confirmed two factor structure, internal consistency (Cronbach's α mean, 95% CI: D-12 Total = 0.93, 0.91-0.94; MDP Immediate Perception [IP] = 0.88, 0.85-0.90; MDP Emotional Response [ER] = 0.86, 0.82-0.89) and 14 day test-rest reliability (ICC: D-12 Total = 0.91, 0.88-0.94; MDP IP = 0.85, 0.70-0.93; MDP ER = 0.84, 0.73-0.90) across settings and languages. MCID estimates for clinical interventions ranged between -3 and -6 points (D-12 Total) with small variability in scores over 2 weeks (D-12 Total 2.8 (95% CI: 2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1) and six months (D-12 Total 2.9 (2.0 to 3.7), MDP-A1 0.8 (0.6 to 1.1)).

CONCLUSION

D-12 and MDP are widely used, reliable, valid and responsive across various chronic conditions, settings and languages, and could be considered standard instruments for measuring dimensions of breathlessness in international trials.

[Inspiratory muscle training during pulmonary rehabilitation]

INTRODUCTION

Inspiratory muscle training (IMT) is part of the management of patients with pulmonary diseases during rehabilitation. Since the last recommendations of the Société de pneumologie de langue française, several studies have focused on the role of inspiratory muscle training during pulmonary rehabilitation.

BACKGROUND

IMT, in comparison to standard care or sham-IMT, improves the strength and endurance of the inspiratory muscles, decreases dyspnoea during the activities of daily living, improves walking distance and quality of life. However, the different studies did not show an additional effect of IMT during a pulmonary rehabilitation program compared to a rehabilitation program without IMT, with regard to improvement of exercise capacity and quality of life.

OUTLOOK

One study showed an improvement in dyspnoea of effort, but these results are yet to be confirmed. Finally, it seems appropriate to associate IMT with an exercise-training program before chest or abdominal surgery, even if further studies are necessary.

CONCLUSION

During a pulmonary rehabilitation program, IMT does not provide additional benefits. However, when patients cannot perform a global exercise training, IMT has shown benefit. IMT provides additional benefits in pre-operative programs.

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.

Intolerance to and limitations of inspiratory muscle training in patients with advanced chronic obstructive pulmonary disease: A report of two cases

Inspiratory muscle training (IMT) has been attracting attention as one of the useful treatments in patients with chronic obstructive pulmonary disease (COPD). IMT is reportedly effective in most patients with COPD. However, little is known about the benefits of IMT, especially in patients with advanced COPD. We reported two cases of COPD that received 12-week IMT to explore intolerance to and the limitations of IMT in advanced COPD. The effectiveness of IMT was evaluated using cardiopulmonary exercise testing (CPET), spirometry, and respiratory muscle strength testing before and after the training. A 75-year-old man with normal body mass index (BMI) and forced expiratory volume in 1 s (FEV₁) of 1.63 L responded well to IMT, but a 78-year-old man with low BMI and FEV₁ of 0.83 L did not. In the responder, IMT resulted in increased minute ventilation (V' _E) and oxygen uptake at peak exercise in incremental load testing. Moreover, IMT increased endurance time in constant load testing and maximal inspiratory pressure. In both patients, breathing frequency (f _R) increased, but tidal volume and the inspiratory-expiratory ratio were not improved during exercise. Despite the high f _R obtained after IMT, V' _E at peak exercise did not increase and endurance time shortened in the non-responder. In underweight patients with advanced COPD, IMT might lead to tachypnea and ventilatory inefficiency, which in turn might decrease exercise performance. Therefore, underweight patients with advanced COPD might be unable to tolerate IMT and should avoid receiving the training.

Acute effects of expiratory positive pressure on autonomic cardiac modulation during spontaneous and slow deep breathing in COPD patients

AIM

to evaluate the acute effects of expiratory positive airway pressure on cardiac autonomic modulation in chronic obstructive pulmonary disease patients during spontaneous breathing and slow deep breathing.

METHODS

17 patients were evaluated. The R-R intervals were collected (Polar® S810i) during spontaneous breathing (10 minutes) and slow deep breathing (4 minutes), with and without 5 cmH2O expiratory positive airway pressure. Stable signals were analyzed by Kubios®. Heart rate variability indices were computed in time domain and in frequency domain.

RESULTS

Expiratory positive airway pressure application affected low frequency (spontaneous breathing: 62.5±4.1 vs slow deep breathing: 28.2±4.2, p<0.001) and high frequency (spontaneous breathing: 37.4±17.3 vs slow deep breathing: 58.9±18.1, p<0.001). Interactions were observed between expiratory positive airway pressure effect and slow deep breathing effect for low frequency (p<0.001), high frequency (p<0.001) and low frequency/high frequency ratio (p<0.001). When patients were stratified by disease's severity, we identified a significant low frequency reduction (p<0.001) and high frequency increase (p<0.001) for all stages when slow deep breathing was associated with expiratory positive airway pressure.

CONCLUSION

A 5 cmH2O expiratory positive airway pressure during spontaneous and slow deep breathing can elicit an acute response, resulting in a cardiac autonomic control improvement in moderate-to-very severe patients.

Therapeutic pulmonary telerehabilitation protocol for patients affected by COVID-19, confined to their homes: study protocol for a randomized controlled trial

Background

In December 2019, 27 cases of pneumonia, of unknown cause, were identified in the province of Hubei (China). The WHO declared the situation as a Public Health Emergency of International Concern, and it was finally declared a global pandemic on March 11, 2020. The Spanish Government obliges the entire population to remain confined to their homes, with the exception of essential basic services, to stop the spread of COVID-19. Home isolation implies a notable physical deconditioning. Telerehabilitation methods have reported positive experiences, and we propose to study in affected patients of COVID-19, due to the general house confinement of the entire Spanish population.

Methods

Patients will be recruited in the regions of Andalusia, Murcia, and Valencia (Spain). Patients will remain confined to their homes, and there, they will carry out their assigned exercise program, which will be controlled telematically. Evaluators will attend to carry out all measurements at the beginning, during, and end of the study, telematically controlled. The patients will be randomly divided into three groups, two of them will perform a home exercise program (breathing exercises or non-specific exercises for muscle toning) and the third group will perform sedentary activities, using mental activation techniques, and will act as a sham group. We will evaluate respiratory variables and other variables of the physical state through physical tests, effort, and perceived fatigue. The data will be statistically analyzed, and the hypotheses will be tested between the groups, using the SPSS software, v.24, considering a 95% confidence interval.

Discussion

We will analyze the results, in terms of the level of fatigue and perceived exertion, physical health, and maintenance of respiratory activity of two types of exercise programs, toning and respiratory, applied in patients affected by COVID-19 during the period of home confinement. We intend to investigate a field not previously studied, such as the repercussion of carrying out a toning and respiratory exercise program in these patients, in historical circumstances that no one had previously observed in Spain, since the general population has never been forced to remain confined in their homes, due to a pandemic infection, by a coronavirus (COVID-19). Observing the effects that these two home exercise programs could produce in patients infected with COVID-19, we will try to better analyze and understand the mechanisms that are associated with the worsening of breathing in this type of patient.

Trial registration

Brazilian Clinical Trial Registry RBR-6m69fc. Registered on March 31, 2020.

Effects of a Rehabilitation Programme with a Nasal Inspiratory Restriction Device on Exercise Capacity and Quality of Life in COPD

Objective: The objective was to assess the effects of a nasal restriction device for inspiratory muscle training, called Feelbreathe^®, added to a rehabilitation program (RP) on exercise capacity, quality of life, dyspnea and inspiratory muscle strength in patients with stable COPD. Methods: Patients were randomized into three groups, one performed a supervised RP using the Feelbreathe^® device (FB group), the second group developed the same RP with oronasal breathing without FB (ONB group) and the third was the control group (CG). We evaluated inspiratory muscle strength (PImax), dyspnea (mMRC), quality of life (CAT) and exercise capacity (6MWT) before and after 8-week of RP. Results: A total of 16 patients completed the study, seven in FB group, five in ONB group and four in the CG. After the RP, the FB group showed a significant increase in PImax (93.3 ± 19.1 vs. 123.0 ± 15.8 mmHg) and in the 6MWT distance (462.9 ± 71.8 m vs. 529.1 ± 50.1 m) and a decrease in the CAT score (9.7 ± 6.5 vs. 5.9 ± 6.0) and in the mMRC dyspnea score. FB provides greater improvement in PImax, dyspnea, quality of life and 6MWT than ONB. Conclusions: The Feelbreathe^® device provides greater improvements in quality of life, dyspnea, exercise capacity and inspiratory muscle strength compared to patients that did not use it.

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.

Pulmonary function and functional capacity cut-off point to establish sarcopenia and dynapenia in patients with COPD

Objective

To establish a cut-off point for clinical and functional variables to determinate sarcopenia and dynapenia in COPD patients, and to analyze the impact of skeletal muscle dysfunction (SMD) on these variables.

Methods

Cross-sectional study, screened COPD patients for sarcopenia or dynapenia through low muscle mass and hand grip strength (HGS). Clinical variables: pulmonary function, respiratory muscle strength and functional capacity (FC). The precision of the variables in determining points of predictive cut-off for sarcopenia or dynapenia were performed using the Receiver Operating Characteristic curve and two-way analysis of variance.

Results

20 COPD patients stratified for sarcopenia (n = 11) and dynapenia (n = 07). Sarcopenia group presented lower lean mass and lower maximal inspiratory pressure (MIP), decreased HGS, reduced FC (p<0.050). Dynapenia group presented reduced MIP, lower HGS and walked a shorter distance at Incremental shuttle walk test (ISWT) (p<0.050). We found cut-off points of forced expiratory volume in one second (FEV1), MIP and maximal expiratory pressure (MEP) and ISWT. It is possible to identify sarcopenia or dynapenia in these patients. We found the coexistence of the conditions (SMD effect) in COPD – reduction in the distance in the ISWT (p = 0.002) and %ISWT (p = 0.017).

Conclusion

In moderate to very severe COPD patients the sarcopenia could be predicted by FEV₁ (%predicted) < 52, MIP < 73 cmH2O, MEP < 126 cmH2O and distance traveled of < 295 m in ISWT. Whereas dynapenia could be predicted by FEV₁ < 40%, MIP < 71 cmH2O, MEP < 110 cmH2O and distance of < 230 m traveled in ISWT.

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.

Inspiratory muscle strength, diaphragmatic mobility, and body composition in chronic obstructive pulmonary disease

BACKGROUND AND PURPOSE

Chronic obstructive pulmonary disease (COPD) is a systemic inflammatory disease that can cause repercussions on respiratory muscles and body composition. The aim of the current study was to evaluate inspiratory muscle strength, diaphragmatic mobility, and body composition in COPD subjects and to correlate these variables.

METHODS

This was a cross-sectional study performed with 21 COPD patients. Inspiratory muscle strength (manovacuometry), pulmonary function test (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV₁ ], and FEV₁ /FVC ratio), diaphragmatic mobility (ultrasonography), and body composition (bioelectrical impedance analysis) were examined.

RESULTS

COPD individuals in Stages II (28.9%), III (52%), and IV (19%) according to Global Initiative for Chronic Obstructive Disease were recruited, 61.9% of which were men. Inspiratory muscle weakness was found in 47.6% of subjects, who presented a lower fat-free mass percentage (p = 0.017) and smaller fat-free mass index (p = 0.001) and greater fat mass percentage (p = 0.029) and less diaphragmatic mobility (p = 0.007) compared with the nonrespiratory weakness group. Maximal inspiratory pressure exhibited a moderately positive relationship to the fat-free mass index (r = 0.767, p < 0.001) and a weak positive relationship to diaphragmatic mobility (r = 0.496, p = 0.022).

CONCLUSION

Our study showed a high prevalence of inspiratory muscle weakness based on the severity of airway obstruction and on the presence of muscular depletion. The evaluation of body composition detected important changes. It also demonstrated that not only muscular weakness was present in these patients but also this had repercussions on the mobility of the diaphragm muscle.

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.

Influence of expiratory positive airway pressure on cardiac autonomic modulation at rest and in submaximal exercise in COPD patients

The aim of this study was to evaluate the effect of expiratory positive airway pressure (EPAP) on heart rate variability (HRV) indices at rest and during 6-min walk test (6MWT) in chronic obstructive pulmonary disease (COPD) patients. Fifteen moderate to severe COPD patients were randomized and evaluated with and without (Non-EPAP) a 5 cmH₂O EPAP device. Respiratory rate (RR) was collected at rest (5 min), during the 6MWT (5 min), and at recovery (5 min). Indices of HRV were computed in the time domain, in the frequency domain, and nonlinear analysis. For EPAP and Non-EPAP during the 6MWT, we found an increased mean heart rate (HR) (P=0.001; P=0.001) while mean RR (P=0.001; P=0.015) and RR tri index decreased (P=0.006; P=0.028). Peripheral oxygen saturation (P=0.019) increased at rest only in the EPAP group. In EPAP, correlations were found between forced expiratory volume in 1 s (FEV₁) and low frequency (LF) sympathetic tonus (P=0.05; r=-0.49), FEV₁ and high frequency (HF) parasympathetic tonus at rest (P=0.05; r=0.49), lactate at rest and LF during the 6MWT (P=0.02; r=-0.57), and lactate at rest and HF during 6MWT (P=0.02; r=0.56). Through a linear regression model, we found that lactate at rest explained 27% of the alterations of LF during 6MWT. The use of 5 cmH₂O EPAP improved autonomic cardiac modulation and its complexity at rest in COPD patients. Although it did not influence the performance of the 6MWT, the EPAP device caused alterations in resting lactate concentration with an effect on sympatho-vagal control during the test.

Effects of inspiratory muscle training on dyspnoea in severe COPD patients during pulmonary rehabilitation: controlled randomised trial

The benefit of inspiratory muscle training (IMT) combined with a pulmonary rehabilitation programme (PRP) is uncertain. We aimed to demonstrate that, in severe and very severe chronic obstructive pulmonary disease (COPD) patients, IMT performed during a PRP is associated with an improvement of dyspnoea.In a single-blind randomised controlled trial, 150 severe or very severe COPD patients were allocated to follow PRP+IMT versus PRP alone. The evaluations were performed at inclusion and after 4 weeks. The primary outcome was the change in dyspnoea using the Multidimensional Dyspnoea Profile questionnaire at the end of a 6-min walk test (6MWT) at 4 weeks. Secondary outcomes were changes in dyspnoea using the Borg (end of the 6MWT) and modified Medical Research Council scales and in functional parameters (maximal inspiratory pressure (P_Imax), inspiratory capacity, 6MWT and quality of life). All analyses were performed on an intention-to-treat basis.Dyspnoea decreased significantly in both groups; however, the improvement of dyspnoea was not statistically different between the two groups. We only found a statistically significant greater increase of P_Imax after IMT+PRP than after PRP alone.In this trial including severe or very severe COPD patients, we did not find a significant benefit of IMT during PRP+IMT as compared to PRP alone on dyspnoea, despite a significantly higher improvement of P_Imax in the IMT group.

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.

Cycle ergometer and inspiratory muscle training offer modest benefit compared with cycle ergometer alone: a comprehensive assessment in stable COPD patients

BACKGROUND

Cycle ergometer training (CET) has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT) may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment.

MATERIALS AND METHODS

Eighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group), 27 received 8 weeks of CET alone (CET group), and 26 only received 8 weeks of free walking (control group). Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program.

RESULTS

Respiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group (P<0.05) after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPI_max [maximal inspiratory pressure] 5.20±0.89 cmH₂O vs 1.32±0.91 cmH₂O; P<0.05). However, there were no significant differences in the other indices between the two groups (P>0.05). Patients with weakened respiratory muscles in the combined training group derived no greater benefit than those without respiratory muscle weakness (P>0.05). There were no significant differences in these indices between the patients with malnutrition and normal nutrition after pulmonary rehabilitation program (P>0.05).

CONCLUSION

Combined training is more effective than CET alone for increasing inspiratory muscle strength. IMT may not be useful when combined with CET in patients with weakened inspiratory muscles. Nutritional status had slight impact on the effects of pulmonary rehabilitation. A comprehensive assessment approach can be more objective to evaluate the effects of combined CET and IMT.

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

Background

The aim of this study was to evaluate the efficiency of a simple prototype device for training respiratory muscles in lung function, respiratory muscle strength, walking capacity, quality of life (QOL), dyspnea, and oxidative stress in patients with COPD.

Methods

Thirty COPD patients with moderate severity of the disease were randomized into three groups: control (n=10, 6 males and 4 females), standard training (n=10, 4 males and 6 females), and prototype device (n=10, 5 males and 5 females). Respiratory muscle strength (maximal inspiratory pressure [PImax] and maximal expiratory pressure [PEmax]), lung function (forced vital capacity [FVC], percentage of FVC, forced expiratory volume in 1 second [FEV₁], percentage of FEV₁ [FEV₁%], and FEV₁/FVC), 6-minute walking distance (6MWD), QOL, and oxidative stress markers (total antioxidant capacity [TAC]), glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) were evaluated before and after 6 weeks of training. Moreover, dyspnea scores were assessed before; during week 2, 4, and 6 of training; and at rest after training.

Results

All parameters between the groups had no statistical difference before training, and no statistical change in the control group after week 6. FVC, FEV₁/FVC, PImax, PEmax, QOL, MDA, and NO showed significant changes after 6 weeks of training with either the standard or prototype device, compared to pre-training. FEV₁, FEV₁%, 6MWD, TAC, and GSH data did not change statistically. Furthermore, the results of significant changes in all parameters were not statistically different between training groups using the standard and prototype device. The peak dyspnea scores increased significantly in week 4 and 6 when applying the standard or prototype device, and then lowered significantly at rest after 6 weeks of training, compared to pre-training.

Conclusion

This study proposes that a simple prototype device can be used clinically in COPD patients as a standard device to train respiratory muscles, improving lung function and QOL, as well as involving MDA and NO levels.

Is cardiac autonomic modulation during upper limb isometric contraction and Valsalva maneuver impaired in COPD patients?

PURPOSE

To evaluate the heart rate variability (HRV) indices and heart rate (HR) responses during isometric contraction (IC) and Valsalva maneuver (VM) in COPD patients.

METHODS

Twenty-two stable moderate to severe COPD patients were evaluated. R-R intervals were recorded (monitor Polar^® S810i) during dominant upper limb IC (2 minutes). Stable signals were analyzed by Kubios HRV^® software. Indices of HRV were computed in the time domain (mean HR; square root of the mean squared differences of successive RR intervals [RMSSD] and HRV triangular index [RR tri index]) and in the frequency domain (high frequency [HF]; low frequency [LF] and LF/HF ratio). The HR responses were evaluated at rest, at the peak and at the nadir of the VM (15 seconds). The Valsalva index was also calculated.

RESULTS

During IC: time domain indices (mean HR increased [P=0.001], RMSSD, and RR tri index decreased [P=0.005 and P=0.005, respectively]); frequency domain indices (LF increased [P=0.033] and HF decreased [P=0.002]); associations were found between forced expiratory volume in 1 second (FEV₁) vs RMSSD (P=0.04; r=-0.55), FEV₁ vs HR (P=0.04; r=-0.48), forced vital capacity (FVC) vs RMSSD (P=0.05; r=-0.62), maximum inspiratory pressure (MIP) vs HF (P=0.02; r=0.68). FEV₁ and FVC justified 30% of mean HR. During VM: HR increased (P=0.01); the nadir showed normal bradycardic response; the Valsalva index was =0.7.

CONCLUSION

COPD patients responded properly to the upper limb IC and to the VM; however, HR recovery during VM was impaired in these patients. The severity of the disease and MIP were associated with increased parasympathetic modulation and higher chronotropic response.

Electrically induced mechanomyograms reflect inspiratory muscle strength in young or elderly subjects

BACKGROUND

Respiratory muscle strength has been used as a tool for evaluating respiratory rehabilitation in chronic obstructive pulmonary disease. However, mouth pressure measurement evaluated by maximum expiratory mouth pressure (PEmax) or inspiratory mouth pressure (PImax) offers an indirect method for measuring respiratory muscle strength. We demonstrated the evaluation of diaphragm contractility using a mechanomyogram (MMG), which is the mechanical signal generated by the motion of the diaphragm induced by the electric stimulation of the phrenic nerve.

METHODS

Study participants were 21 young and 20 elderly subjects with no symptoms of respiratory disease. The elderly subjects were divided into non-smoker or smoker groups. The smoker group was defined as subjects having a Brinkman Index of greater than 300. We measured basic spirometric parameters, mouth pressure (PEmax, PImax), and diaphragmatic MMG.

RESULTS

Diaphragmatic MMG showed more clear contrast between young subjects and elderly non-smoker or smoker subjects than the conventional method for respiratory muscle contraction (PEmax, PImax). In addition, the diaphragmatic MMG strongly correlated with inspiratory muscle strength.

CONCLUSIONS

Diaphragmatic MMG may reflect diaphragmatic contractility more directly and sensitively than the conventional method.