Exercise training increases respiratory muscle strength and exercise capacity in patients with chronic obstructive pulmonary disease and respiratory muscle weakness

BackgroundHow respiratory muscle strength influences the effectiveness of pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD) is unclear.ObjectiveTo investigate the benefits of PR in subjects with COPD according to respiratory muscle strength.MethodsNinety-seven subjects with COPD were evaluated using maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), pulmonary function tests, the cardiopulmonary exercise test (CPET), and the St. George's Respiratory Questionnaire (SGRQ). Subjects were divided into four groups: 1 (normal MIP and MEP); 2 (low MIP); 3 (low MEP); and 4 (low MIP and MEP). Subjects underwent PR for 3 months; MIP, MEP, SGRQ, and CPET were evaluated post-PR.ResultsSubjects with both poor MIP and MEP had the highest dyspnea score, lowest exercise capacity, and poorest health-related quality of life (HRQoL). PR improved exercise capacity and HRQoL in all groups, with more improvement in MIP, MEP, tidal volume (on exercise), and dyspnea (at rest) in subjects with both low MIP and MEP.ConclusionsPatients with respiratory muscle weakness had worse dyspnea, lower exercise capacity, and poorer HRQoL at baseline. Exercise training improved respiratory muscle strength with concurrent improvement of exercise capacity, HRQoL, and dyspnea score. Subjects with both poor baseline MIP and MEP showed greater benefits of PR.     

Home-based pulmonary rehabilitation in patients with inoperable or residual chronic thromboembolic pulmonary hypertension: A preliminary study

BackgroundManagement of chronic thromboembolic pulmonary hypertension (CTEPH) has recently improved because of advances in pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA), and disease-targeted medications. However, patients with inoperable CTEPH or persistent pulmonary hypertension (PH) after these interventions continue to exhibit impaired exercise capacity and limited quality of life (QOL).MethodsEight patients with inoperable or residual CTEPH (mean age, 64±12 years; WHO functional class II/III, 6/2; mean pulmonary artery pressure, 47±13 mmHg) in stable condition and receiving disease-targeted medications participated in a 12-week home-based pulmonary rehabilitation program (muscle strength training, respiratory exercises, and walking) with supervised hospital sessions from March 2012 to January 2014. Efficacy parameters were prospectively evaluated at baseline and at completion of the 12-week program.ResultsAfter completion of the pulmonary rehabilitation program, the 6-minute walking distance (6MWD) (33.3±25.1 m), St. George׳s Respiratory Questionnaire activity score, quadriceps force, and 7-day physical activity level were significantly improved compared with baseline. All subjects completed the rehabilitation program. Although one patient experienced presyncope during the in-hospital exercise sessions, no other severe adverse events or complications of pulmonary rehabilitation were observed.ConclusionsThese findings suggest that home-based pulmonary rehabilitation with closely supervised sessions may safely improve exercise capacity, leg muscle strength, general activity in daily life and health-related QOL in CTEPH patients.     

Effects of inspiratory muscle training in patients with heart failure

Aim

To investigate the effects of inspiratory muscle training (IMT) on functional capacity and balance, respiratory and peripheral muscle strength, pulmonary function, dyspnea, fatigue, depression, and quality of life in heart failure patients.

Methods

A prospective, randomized controlled, double-blinded study. Thirty patients with heart failure (NYHA II-III, LVEF<40%) were included. Sixteen patients received IMT at 40% of maximal inspiratory pressure (MIP), and 14 patients received sham therapy (15% of MIP) for 6 weeks. Functional capacity and balance, respiratory muscle strength, quadriceps femoris muscle strength, pulmonary function, dyspnea, fatigue, quality of life, and depression were evaluated.

Results

Functional capacity and balance, respiratory and peripheral muscle strength, dyspnea, depression were significantly improved in the treatment group compared with controls; quality of life and fatigue were similarly improved within groups (p < 0.05). Functional capacity (418.59 ± 123.32 to 478.56 ± 131.58 m, p < 0.001), respiratory (MIP = 62.00 ± 33.57 to 97.13 ± 32.63 cmH₂O, p < 0.001) and quadriceps femoris muscle strength (240.91 ± 106.08 to 301.82 ± 111.86 N, p < 0.001), FEV₁%, FVC% and PEF%, functional balance (52.73 ± 3.15 to 54.25 ± 2.34, p < 0.001), functional dyspnea (2.27 ± 0.88 to 1.07 ± 0.79, p < 0.001), depression (11.47 ± 7.50 to 3.20 ± 4.09, p < 0.001), quality of life, fatigue (42.73 ± 11.75 to 29.07 ± 13.96, p < 0.001) were significantly improved in the treatment group. Respiratory muscle strength (MIP = 78.64 ± 35.95 to 90.86 ± 30.23 cmH₂O, p = 0.001), FVC%, depression (14.36 ± 9.04 to 9.50 ± 10.42, p = 0.011), quality of life and fatigue (42.86 ± 12.67 to 32.93 ± 15.87, p = 0.008) were significantly improved in the control group.

Conclusion

The IMT improves functional capacity and balance, respiratory and peripheral muscle strength; decreases depression and dyspnea perception in patients with heart failure. IMT should be included effectively in pulmonary rehabilitation programs.     

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

Abstract

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

Respiratory and limb muscle function in lung allograft recipients.

Lung transplantation recipients have reduced exercise capacity despite normal resting pulmonary and hemodynamic function. The limiting factor may be contractile dysfunction of skeletal muscle. To test this postulate, we measured limb and respiratory muscle function in nine clinically stable lung allograft recipients (six men and three women, aged 30 to 65 yr, at 5 to 102 mo after transplantation) with reduced exercise capacity. Respiratory muscle strength was tested by measuring maximal inspiratory and expiratory pressure (MIP and MEP, respectively). Ankle dorsiflexor muscle strength was measured during maximal voluntary contraction (MVC). In a subset of six recipients, we also measured contractile properties and fatigue characteristics of the tibialis anterior muscle, using electrical stimulation of the motor point. Data were compared with values from age- and sex-matched control subjects. MIP values of transplant recipients did not differ from control values; however, MEP was blunted by 30% relative to control (p < 0.05), and MVC was decreased by 39% (p < 0.05). The force-frequency relationships and fatigue characteristics of the tibialis anterior were not different between the patient and control groups. We conclude that stable lung allograft recipients experience expiratory and lower limb weakness that may contribute to exercise intolerance.     

Muscle performance and fatigue in compensated chronic liver disease

Abstract

Background: A common and debilitating symptom in patients with chronic liver disease is fatigue (CLD). Muscle dysfunction has been suggested to be a key mechanism of fatigue in CLD.

Objective: We aimed to evaluate fatigue and the potential association with muscle performance and physical activity in outpatients with CLD.

Methods: Two-hundred seventy outpatients with CLD were included, (52?±?15 years, mean?±?SD; 151 females) with autoimmune hepatitis (n?=?49), primary biliary cholangitis (n?=?45), primary sclerosing cholangitis (n?=?46), chronic hepatitis B (n?=?57) or C (n?=?73). Patients with a Child-Pugh >6 were excluded. The questionnaire Fatigue Impact Scale (FIS) was used to evaluate fatigue, and physical activity was evaluated through a self-reported level of physical activity. Muscle function was assessed with four muscle tests, walking speed, handgrip strength, standing heel-rise test (SHT) and ‘Timed Up and Go’ test (TUG).

Results: The median total FIS score was 30 (40% had FIS > 40, considered high-fatigue). Diminished muscle performance was observed in the SHT (% of predicted value: 53?±?26%) and with maximum grip strength (85?±?20%). The FIS score was significantly different between groups of CLDs (p?=?.004). In multivariate analysis the TUG (p?=?.001), SHT (p?=?.005), antidepressants (p?p?=?.001) were associated with fatigue (R²?=?29%). Subjects with higher levels of physical activity had lower FIS (p?Conclusions: In patients with CLD, fatigue was associated with low muscle performance and reduced level of physical activity, which could be a potential therapeutic target.     

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.     

Resting Physiological Correlates of Reduced Exercise Capacity in Smokers with Mild Airway Obstruction

Smokers with minor spirometric abnormalities can experience persistent activity-related dyspnea and exercise intolerance. Additional resting tests can expose heterogeneous physiological abnormalities, but their relevance and association with clinical outcomes remain uncertain. Subjects included sixty-two smokers (≥20 pack-years), with cough and/or dyspnea and minor airway obstruction [forced expiratory volume in one-second (FEV₁) ≥80% predicted and >5th percentile lower limit of normal (LLN) (i.e., z-score >?1.64) using the 2012-Global Lung Function Initiative equations]. They underwent spirometry, plethysmography, oscillometry, single-breath nitrogen washout, and symptom-limited incremental cycle exercise tests. Thirty-two age-matched nonsmoking controls were also studied. Thirty-three (53%) of smokers had chronic obstructive pulmonary disease by LLN criteria. In smokers [n = 62; age 65 ± 11 years; smoking history 43 ± 19 pack-years; post-bronchodilator FEV₁ z-score ?0.60 ± 0.72 and FEV₁/FVC z-score ?1.56 ± 0.87 (mean ± SD)] versus controls, peak oxygen uptake (?VO₂) was 21 ± 7 vs. 32 ± 9 ml/kg/min, and dyspnea/?VO₂ slopes were elevated (both p < 0.0001). Smokers had evidence of peripheral airway dysfunction and maldistribution of ventilation when compared to controls. In smokers versus controls: lung diffusing capacity for carbon monoxide (D_LCO) was 85 ± 22 vs. 105 ± 17% predicted, and residual volume (RV)/total lung capacity (TLC) was 36 ± 8 vs. 31 ± 6% (both p < 0.01). The strongest correlates of peak ?VO₂ were D_LCO% predicted (r = 0.487, p < 0.0005) and RV/TLC% (r = ?0.389, p = 0.002). D_LCO% predicted was also the strongest correlate of dyspnea/?VO₂ slope (r = ?0.352, p = 0.005). In smokers with mild airway obstruction, associations between resting tests of mechanics and pulmonary gas exchange and exercise performance parameters were weak, albeit consistent. Among these, DLCO showed the strongest association with important outcomes such as dyspnea and exercise intolerance measured during standardized incremental exercise tests.     

Depression partially mediated the relationship between basic psychological needs and quality of life among people living with HIV

Few studies have examined the relationship between basic psychological needs (BPN), depression and quality of life (QOL) in people living with HIV (PLWH). This cross-sectional study (N?=?65; 37% females, 37% Caucasian, mean age?=?55?±?6 years, mean CD4 count?=?668?±?368?cells/mm³, average duration of HIV?=?18?±?4 years) found that BPN frustration was related with lower QOL. The strength of this relationship was reduced after controlling for depression. This suggests that depression partially mediated the relationship between BPN and QOL. BPN and depression may be specific targets for psychosocial interventions aimed at improving QOL in PLWH to promote successful aging.     

Effects of inspiratory muscle training in COPD patients: A systematic review and meta‐analysis

Objectives

In chronic obstructive pulmonary disease (COPD), quality of life and exercise capacity are altered in relationship to dyspnea. Benefits of inspiratory muscle training (IMT) on quality of life, dyspnea, and exercise capacity were demonstrated, but when it is associated to pulmonary rehabilitation (PR), its efficacy on dyspnea is not demonstrated. The aim of this systematic review with meta‐analysis was to verify the effect of IMT using threshold devices in COPD patients on dyspnea, quality of life, exercise capacity, and inspiratory muscles strength, and the added effect on dyspnea of IMT associated with PR (vs. PR alone).

Study selection

This systematic review and meta‐analysis was conducted on the databases from PubMed, Science direct, Cochrane library, Web of science, and Pascal. Following key words were used: inspiratory, respiratory, ventilatory, muscle, and training. The searching period extended to December 2017. Two reviewers independently assessed studies quality.

Results

Forty‐three studies were included in the systematic review and thirty‐seven studies in the meta‐analysis. Overall treatment group consisted of six hundred forty two patients. Dyspnea (Baseline Dyspnea Index) is decreased after IMT. Quality of life (Saint George's Respiratory Questionnaire), exercise capacity (6 min walk test) and Maximal inspiratory pressure were increased after IMT. During PR, no added effect of IMT on dyspnea was found.

Conclusion

IMT using threshold devices improves inspiratory muscle strength, exercise capacity and quality of life, decreases dyspnea. However, there is no added effect of IMT on dyspnea during PR (compared with PR alone).     

Comparing the effect of pulmonary rehabilitation in patients with uncontrolled and partially controlled asthma

Objective: Pulmonary rehabilitation (PR) is an important therapeutic approach in asthmatic patients. Lack of asthma control is associated with high morbidity, poor health outcomes, and decrease in quality of life (QOL). However, there is no clear information about the effectiveness of PR in patients with differing levels of asthma control. This study aimed to compare the efficacy of PR in patients with uncontrolled and partially controlled asthma. Methods: Before undergoing an 8-week outpatient PR program, patients were classified according to the asthma control test (ACT) as having partially controlled asthma or uncontrolled asthma. Changes in asthma control, exercise capacity, dyspnea perception, pulmonary function tests, arterial blood gas analysis, QOL, and psychological symptoms before and after PR were compared between groups. Results: A total of 49 patients, 21 of whom were in partially controlled and the rest 28 were in uncontrolled asthma, participated in the study. After PR, asthma control perceived dyspnea, exercise capacity, QOL, anxiety, and depression significantly improved in both groups (p < 0.05). When the two groups were compared in terms of the benefits of PR, the improvement in ACT score was significantly greater in patients with uncontrolled asthma than in partially controlled asthma (p < 0.001), whereas the improvements in other parameters were similar between groups (p > 0.05). Conclusions: Improvement in asthma control is greater in patients with uncontrolled asthma than in patients with partially controlled asthma after PR. Therefore, patients with uncontrolled asthma, in particular, should be given opportunities to benefit from PR programs.     

Selective low-level leg muscle training alleviates dyspnea in patients with heart failure

OBJECTIVES: The purpose of this study was to demonstrate in patients with moderate to severe heart failure that exertional dyspnea can be alleviated by improving muscle function. BACKGROUND: Dyspnea is a frequent limiting symptom in patients with chronic heart failure (CHF). This sensation may originate from activation of receptors in the musculature rather than the lung. METHODS: To investigate whether dyspnea could be alleviated by selective changes in leg muscle function, we performed isolated lower-limb training in 17 patients with severe CHF. Eight patients learned guided imagery relaxation techniques and served as an active control group. Exercise training consisted of three months of low-level bicycle and treadmill exercise such that minute ventilation was <25 l/min. Leg calisthenics were also performed. Maximal and submaximal exercise performance, respiratory and quadriceps muscle strength and endurance and quality-of-life and dyspnea scales were measured before and after each intervention. Metabolic stress testing (VO(2)), pulmonary function tests and isokinetic strength testing were also performed. RESULTS: In the active control group, no changes in leg muscle function, pulmonary function, maximal and submaximal exercise performance or quality-of-life questionnaires were observed. In the training group, peak torque of leg flexors (pre: 39 +/- 15 ft-lb; post: 50 +/- 13 ft-lb; p < 0.002) increased and the fatigue ratio decreased, indicating improved strength and endurance of the leg muscles. Maximal inspiratory and expiratory mouth pressures and maximum voluntary ventilation were unchanged. Peak VO(2) was increased (pre:12 +/- 2.2 ml/kg/min; post: 14 +/- 2.6 ml/kg/min) as well as the duration of exercise at 70% peak VO(2) increased (pre: 11.5 +/- 3.1 min; post: 21.5 +/- 5.4 min; p < 0.003). Perceived dyspnea during the submaximal testing was decreased. Minnesota Living with Heart Failure Score, Guyatt Dyspnea Scale, and the Transitional Dyspnea Index were all improved with training (all p < 0.05). CONCLUSIONS: We concluded that improvement of limb muscle function alleviates dyspnea and improves exercise performance in patients with CHF.     

New approaches in pulmonary rehabilitation

Patients who have mild to severe chronic obstructive pulmonary disease may obtain improvement in dyspnea, exercise capacity, and health-related quality of life as a result of exercise training. The type and intensity of training is of key importance in determining outcomes. High-intensity aerobic training leads to physiologic gains in aerobic fitness. Nevertheless, extreme breathlessness or peripheral muscle fatigue may prevent some patients from performing high-intensity exercise; therefore, new tools are needed to improve the effectiveness of pulmonary rehabilitation.     

Obstructive sleep apnea and craniofacial appearance in MPS type I-Hurler children after hematopoietic stem cell transplantation

Objectives

Mucopolysaccharidosis type I (MPS I) is an inherited lysosomal storage disorder characterized by severe multi-systemic organ manifestations including obstructive sleep apnea syndrome (OSAS). Hematopoietic stem cell transplantation (HSCT) is the treatment of choice in severe MPS I (MPS IH, Hurler syndrome). However, the effect of HSCT on OSAS in MPS IH still remains unclear. The purpose of this study was to analyze respiratory patterns during sleep following HSCT in MPS IH children and to relate these findings to craniofacial abnormalities.

Methods

Overnight polysomnographies of nine MPS IH children (mean age: 8.2 years) previously treated with HSCT were retrospectively analyzed. Magnetic resonance images of the head were assessed with regard to soft and hard tissue abnormalities of the upper respiratory tract.

Results

The mean apnea hypopnea index (AHI) was 5.3 events/h (range, 0.3–12.2), and the majority of apnea/hypopneas were obstructive. Whereas two patients had severe OSAS (AHI?>?10) and two moderate OSAS (5?>?AHI?<?10), five patients had no evidence of OSAS (AHI?<?2.0). Donor cell chimerism was significantly lower in MPS IH patients with OSAS as compared to patients without OSAS (p?<?0.001). The upper airway space and the maxilla were significantly smaller and the adenoids larger in MPS IH patients with OSAS as compared to those of non-OSAS patients.

Conclusion

OSAS was only observed in MPS IH patients with graft failure or low donor cell chimerism. Conversely, successful HSCT seems to ameliorate adenoid hyperplasia and maxillary constriction in MPS IH patients and thereby minimizes the risk of OSAS at least at younger ages.

     

Cycle ergometer and inspiratory muscle training in chronic obstructive pulmonary disease.

In patients with chronic obstructive pulmonary disease (COPD) the intensity of aerobic training is limited by dyspnea. Improving strength of the inspiratory muscles could enhance aerobic exercise training by reducing exercise-related dyspnea. We examined effects of home-based inspiratory muscle training (IMT) and cycle ergometry training (CET) in 53 patients with moderate to severe COPD (FEV(1)% pred, 50 +/- 17 [mean +/- SD]). Patients were randomly assigned to 4 mo of training in one of four groups: IMT, CET, CET + IMT, or health education (ED). Patients were encouraged to train to the limits of their dyspnea. Inspiratory muscle strength and endurance increased in IMT and CET + IMT groups compared with CET and ED groups (p < 0. 01). Peak oxygen uptake increased and heart rate, minute ventilation, dyspnea, and leg fatigue decreased at submaximal work rates in the CET and CET + IMT groups compared with the IMT and ED groups (p < 0. 01). There were no differences between the CET and CET + IMT groups. Home-based CET produced a physiological training effect and reduced exercise-related symptoms while IMT increased respiratory muscle strength and endurance. The combination of CET and IMT did not produce additional benefits in exercise performance and exercise-related symptoms. This is the first study to demonstrate a physiological training effect with home-based exercise training.     

Creatine supplementation and physical training in patients with COPD: A double blind, placebo-controlled study

Study objectives

Patients with chronic obstructive pulmonary disease (COPD) have low exercise capacity and low content of high energetic phosphates in their skeletal muscles. The aim of the present study was to investigate whether creatine supplementation together with exercise training may increase physical performance compared with exercise training in patients with COPD.

Design

In a randomized, double-blind, placebo-controlled study, 23 patients with COPD (forced expiratory volume in one second [FEV₁] < 70% of predicted) were randomized to oral creatine (n = 13) or placebo (n = 10) supplementation during an 8-week rehabilitation programme including exercise training. Physical performance was assessed by Endurance Shuttle Walking Test (ESWT), dyspnea and leg fatigue with Borg CR-10, quality of life with St George’s Respiratory Questionnaire (SGRQ). In addition, lung function test, artery blood gases, grip strength test, muscle strength and fatigue in knee extensors were measured.

Results

COPD patients receiving creatine supplementation increased their average walking time by 61% (ESWT) (p < 0.05) after the training period compared with 48% (p = 0.07) in the placebo group. Rated dyspnea directly after the ESWT decreased significantly from 7 to 5 (p < 0.05) in the creatine group. However, the difference between the groups was not statistically significant neither in walking time nor in rated dyspnea. Creatine supplementation did not increase the health related quality of life, lung function, artery blood gases, grip strength and knee extensor strength/fatigue.

Conclusions

Oral creatine supplementation in combination with exercise training showed no significant improvement in physical performance, measured as ESWT, in patients with COPD compared with exercise training alone.     

Respiratory muscle weakness and its association with exercise capacity in patients with chronic obstructive pulmonary disease

IntroductionAlthough COPD patients commonly present respiratory complaints despite pharmacological treatment, dyspnea does not correlate directly and linearly with spirometric data, a fact that makes it difficult to select patients for pulmonary rehabilitation. Thus, seems logical that the measurement of respiratory muscle strength could help in this initial assessment if it presents a good correlation with exercise capacity. The aim of this study is to assess whether patients with muscle weakness, characterized as a reduction in maximal inspiratory pressure (PImax) below 70% of predicted value, have a good relationship between the assessed respiratory muscle strength and the exercise capacity measured by the 6‐min walk test (6MWT) in patients with COPD.MethodsPatients diagnosed with COPD according to the 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) on regular use of their medications, without exacerbations for 3 months or more and with respiratory muscle weakness (PImax < 70% of predicted) performed 6MWT in a 30‐m‐long flat corridor.ResultsData from 81 patients were analyzed. There was a strong correlation between the distance of the 6MWD with the PImax (r = 0.764, p < 0.0001). When separating the sample by the 350‐m cut in the 6MWD, we found that the patients with the worst performance in the test are those who present the greatest respiratory muscle weakness.ConclusionPImax correlates well with exercise capacity, and patients with respiratory muscle weakness could be referred to a pulmonary rehabilitation protocol tied to inspiratory muscle training.     

Improvements in outcomes for chronic obstructive pulmonary disease (COPD) attributable to a hospital-based respiratory rehabilitation programme

Aim: To determine whether the benefits of pulmonary rehabilitation, demonstrated in selected subjects in randomised controlled studies, can be achieved by a hospital-based respiratory rehabilitation programme conducted as part of routine clinical management. Methods: Design: A prospective longitudinal study of patients with severe chronic obstructive pulmonary disease (COPD) enrolled in a hospital based, non-medically supervised, outpatient, respiratory rehabilitation programme was undertaken. The rehabilitation programme was of pragmatic design and content, supervised by respiratory physiotherapists and comprised seven two hour sessions over one month for groups of six to eight patients. It included education on disease management, practical instruction in coping skills, as well as a progressive aerobic exercise programme for specific muscle training related to functional activities. Subjects were assessed prior to the programme but after optimisation of pharmacologic therapy, at the completion of the programme and at three months and six months post-programme. Principal outcome parameters were exercise capacity (as assessed by a six minute walk distance [MWD] test), degree of perceived breathlessness and quality of life (QOL) (assessed by the Chronic Respiratory Disease Questionnaire [CRDQ]). Results: Fifty-one subjects with severe COPD (Fev₁=0.9±0.4 1) completed the programme. There was a significant improvement in exercise capacity (a six MWD test improved from 375±126 m at baseline to 440±109 m at three months, p<0.005). There were significant improvements in QOL (in the total CRDQ score as well as in the domains of dyspnoea, fatigue and mastery). There was a reduction in the level of perceived dyspnoea (modified Borg Scale). Most improvements were maintained for three and six months following completion of the programme. Compared with the six months preceding the programme there was a reduction in hospital admissions and reduction in courses of oral steroids. Conclusions: An outpatient, hospital-based respiratory rehabilitation programme pragmatically adapted for clinical utility produces substantial and clinically significant improvements in exercise tolerance and QOL, similar in type and magnitude to those obtained in controlled clinical trials. There was an associated reduction in COPD-related morbidity. Such gains were mostly maintained for six months after completion of the programme. Thus respiratory rehabilitation must be regarded as an essential component of a comprehensive clinical programme for the management of COPD.     

Effects of Pulmonary Rehabilitation Including Inspiratory Muscle Training in Patients with Chronic Obstructive Pulmonary Disease after Stratification by the Degree of Static Hyperinflation

Background

Inspiratory muscle training (IMT) improves inspiratory muscle strength, exercise capacity and health status in patients with chronic obstructive pulmonary disease (COPD). However, there is no additional effect on top of comprehensive pulmonary rehabilitation (PR). It is unclear whether patients with different baseline degrees of static hyperinflation respond differentially to IMT as part of a PR program. Therefore, the aim was to study the effects of IMT as an add-on on PR after stratification for baseline degrees of static hyperinflation.

Methods

In this single center retrospective study data were extracted between June 2013 and October 2020 of COPD patients who participated in a comprehensive PR program including IMT. IMT was performed twice daily, one session consisted of 3 series of 10 breaths and training intensity was set initially at a load of approximately 50% of patients’ maximal static inspiratory mouth pressure (MIP). The primary outcome measure was MIP. Secondary outcomes were the distance achieved on the 6-min walk test (6MWD), endurance cycling exercise capacity at 75% of the peak work rate (CWRT) and disease-specific health status using the COPD assessment test.

Results

754 patients with COPD were screened for eligibility and 328 were excluded because of repeated PR programs, missing data or baseline residual volume (RV)?>?350%. In total, 426 COPD patients were categorized into RV categories 50–130% (n?=?84), 131–165% (n?=?86), 166–197% (n?=?86), 198–234% (n?=?85) and 235–349% (n?=?85). In the whole sample, MIP, endurance exercise capacity and health status improved significantly. The change in 6MWD was higher in the lowest baseline degree of static hyperinflation [+?39 (9–92) m] compared with the baseline highest degree of static hyperinflation [+?11 (??18–54) m] (p?<?0.05).

Conclusions

IMT as part of a PR program in patients with COPD with different baseline degrees improved MIP irrespective of the degree of static lung hyperinflation. Improvement in functional exercise capacity was significantly higher in the group with the lowest degree of static hyperinflation compared with the patients with the highest degree of static hyperinflation.

     

Perceptions of fatigue in patients with idiopathic pulmonary fibrosis or sarcoidosis

BackgroundFatigue is highly prevalent in patients with idiopathic pulmonary fibrosis (IPF) or sarcoidosis. However, the difference in fatigue perceptions for these patients is unknown and this may be important to better understand what fatigue means to the individual patient.MethodsThis cross-sectional quantitative study aims to determine the different perceptions of fatigue as ‘frustrating’, ’exhausting’, ‘pleasant’, ‘frightening’ using the Fatigue Quality List and to assess determinants related to these perceptions of fatigue. Beside the fatigue quality connotations, demographics, lung function, fatigue severity (Checklist Individual Strength subscale Fatigue), dyspnea (modified-Medical Research Council), fatigue catastrophizing (Fatigue Catastrophizing Scale), anxiety/depression (Hospital Anxiety and Depression Scale) and general health status (EuroQoL 5-dimension 5-level) were assessed.ResultsMean frequency score of fatigue-related perceptions in patients with IPF was 3.4 points and in patients with sarcoidosis 4.0 points. Severely fatigued patients with IPF reported their fatigue less ‘pleasant’ significantly more often than patients without severe fatigue. Fatigue severity, dyspnea, catastrophizing and general health were significantly correlated with the negative connotation categories of the Fatigue Quality List in patients with IPF. Severely fatigued sarcoidosis patients reported their fatigue perceptions significantly more often as ‘frustrating’, ’exhausting’, ‘frightening’ and less ‘pleasant’ than patients without severe fatigue. Moreover, in patients with sarcoidosis fatigue severity, dyspnea, catastrophizing and depression were significantly associated with all four categories of the Fatigue Quality List that describe the experienced fatigue (P<0.05).ConclusionsThe current findings of experiences of fatigue in patients with IPF or pulmonary sarcoidosis provide insights for professionals treating these patients. Although similarities were found in the several experiences of fatigue across non-severely and severely fatigued patients, differences were also evident and could be mapped for IPF and sarcoidosis.