Rehabilitation in chronic respiratory diseases: In-hospital and post-exacerbation pulmonary rehabilitation.

Exacerbations of chronic obstructive pulmonary disease (COPD) that require hospitalization are important events for patients. Functional impairment and skeletal muscle dysfunction can increase the risk of hospitalization and readmission, independent of lung function. In addition, once a patient is admitted, multiple factors can lead to worsening outcome including immobility, systemic inflammation and nutritional depletion. These non-pulmonary factors are potentially amenable to exercise therapy, as part of pulmonary rehabilitation (PR). Peri-exacerbation PR has an important role in the management of exacerbations of COPD. In this review, we explore how functional limitation and skeletal muscle dysfunction affect patients having a severe exacerbation of COPD, the systemic impact of hospitalization on patients including potential aetiologies and the role of PR around the time of an exacerbation. This includes rehabilitation during the inpatient phase, post-exacerbation rehabilitation and rehabilitation bridging hospital discharge. We also describe potential future developments in peri-exacerbation PR.

High-intensity inspiratory muscle training in bronchiectasis: A randomized controlled trial.

BACKGROUND AND OBJECTIVE: Inspiratory muscle training (IMT) enhances velocity of inspiratory muscle contraction and modifies inspiratory and expiratory time. This study aimed to examine the impact of high-intensity IMT (H-IMT) on exercise capacity in bronchiectasis. METHODS: Forty-five patients were included. Lung function, respiratory muscle strength and endurance, exercise capacity, dyspnoea, fatigue and quality of life (QOL) were evaluated. Patients were randomized into two groups: H-IMT and control groups. Twenty-three patients underwent H-IMT for 8 weeks, using threshold loading with a target workload of maximal inspiratory pressure (MIP) of at least 70%, with 3-min cycles (as 2-min training: 1-min rest intervals) for 21 min. There was a total period of 14 min of loaded breathing and 7 min of recovery. The control group (n = 22) underwent low-intensity IMT at 10% of the initial MIP and was maintained at the same intensity until the end of the training. RESULTS: After training, both MIP and maximal expiratory pressure (MEP) and the incremental shuttle walk distance were increased in the H-IMT group compared with the control group (P < 0.05). There was a significant difference in constant threshold load, time and pressure-time units in the H-IMT group (P < 0.05) but not in the control group (P > 0.05). A significant decrease was found in fatigue in both groups (P < 0.05). The Leicester Cough Questionnaire social score for the H-IMT group decreased significantly after the treatment (P < 0.05). CONCLUSION: The H-IMT increased exercise capacity in patients with non-cystic fibrosis bronchiectasis. It has also positive effects on respiratory muscle strength and endurance, and social aspects of QOL.

Gas exchange responses during 6-min walk test in patients with pulmonary arterial hypertension.

BACKGROUND AND OBJECTIVE: The 6-min walk test (6MWT) is the most widely utilized method of assessing exercise capacity in pulmonary arterial hypertension (PAH). Cardiopulmonary exercise testing has the advantage of providing additional physiological information over 6MWT. The goals of our study were to describe the addition of gas exchange measurements to 6MWT and to determine how these parameters were related to the severity of PAH in three major subgroups of PAH (idiopathic (IPAH), connective tissue disease-related (CTPAH) and congenital heart disease-related (CHPAH)). METHODS: Seventy-six PAH patients (IPAH, n = 28; CTPAH, n = 24; CHPAH, n = 24) completed the 6MWT with simultaneous gas exchange measurements. The 6-min walk distance (6MWD), oxygen uptake ( V ˙ O2 ), carbon dioxide production ( V ˙ CO2 ), oxygen saturation, minute ventilation to carbon dioxide output ( V ˙ E / V ˙ CO2 ) and end-tidal partial pressure for carbon dioxide (PET CO2 ) were compared between subgroups, different functional classes (FCs) and pharmacotherapy. RESULTS: Whilst no significant difference in 6MWT was observed, absolute V ˙ O2 and V ˙ CO2 were higher for IPAH (P < 0.05). Differences were removed when V ˙ O2 and V ˙ CO2 were expressed relative to body mass (i.e. mL/kg/min). CHPAH had the most significant desaturation during 6MWT (CPAH: 73 ± 15%; CTPAH: 90 ± 8%, IPAH: 92 ± 8%, P < 0.01). There was no difference in V ˙ E / V ˙ CO2 and PET CO2 between groups; however, New York Health Association (NYHA) FC II performed better than FC III subjects in 6MWT with lower V ˙ E / V ˙ CO2 and higher end-exercise PET CO2 . Similarly, individuals on more advanced pharmacotherapy (triple therapy vs monotherapy) had poorer gas exchange during exercise. CONCLUSION: Whilst 6MWT and gas exchange did not differentiate between PAH groups, individuals with more severe disease and on more advanced pharmacotherapy had poorer gas exchange during exercise.

Australian and New Zealand Pulmonary Rehabilitation Guidelines.

BACKGROUND AND OBJECTIVE: The aim of the Pulmonary Rehabilitation Guidelines (Guidelines) is to provide evidence-based recommendations for the practice of pulmonary rehabilitation (PR) specific to Australian and New Zealand healthcare contexts. METHODS: The Guideline methodology adhered to the Appraisal of Guidelines for Research and Evaluation (AGREE) II criteria. Nine key questions were constructed in accordance with the PICO (Population, Intervention, Comparator, Outcome) format and reviewed by a COPD consumer group for appropriateness. Systematic reviews were undertaken for each question and recommendations made with the strength of each recommendation based on the GRADE (Gradings of Recommendations, Assessment, Development and Evaluation) criteria. The Guidelines were externally reviewed by a panel of experts. RESULTS: The Guideline panel recommended that patients with mild-to-severe COPD should undergo PR to improve quality of life and exercise capacity and to reduce hospital admissions; that PR could be offered in hospital gyms, community centres or at home and could be provided irrespective of the availability of a structured education programme; that PR should be offered to patients with bronchiectasis, interstitial lung disease and pulmonary hypertension, with the latter in specialized centres. The Guideline panel was unable to make recommendations relating to PR programme length beyond 8 weeks, the optimal model for maintenance after PR, or the use of supplemental oxygen during exercise training. The strength of each recommendation and the quality of the evidence are presented in the summary. CONCLUSION: The Australian and New Zealand Pulmonary Rehabilitation Guidelines present an evaluation of the evidence for nine PICO questions, with recommendations to provide guidance for clinicians and policymakers.

Exercise training in COPD: What is it about intensity?

Most of the current guidelines for pulmonary rehabilitation recommend higher, over lower, intensity exercise training for COPD. Typically, we consider intensity of exercise training to be a key component of any exercise training programme. Whilst studies of young individuals have demonstrated that higher exercise training intensity results in greater improvements in exercise capacity, the evidence for older patients is not so clear cut. In COPD, there is limited evidence regarding the optimal intensity of exercise training. Using both physiological (peak exercise capacity) and patient-centred (e.g. quality of life) outcomes, it remains inconclusive if higher intensity exercise training bestows any greater benefit than low-intensity exercise. If we examine the data from interval training studies, which used both high- and low-intensity interval and continuous exercise, we are able to generate more data for comparison. Unfortunately, these data are challenging to interpret due to heterogeneity in how interval training was prescribed. However, when we normalize the interval training data for training volume and examine the change in peak cycling power, there is a relationship between training intensity and increase in peak power (Wpeak , r = 0.68, P < 0.05). Hence, whilst there is an inconclusive amount of evidence to support this intervention based on studies that only examined high- versus low-intensity continuous exercise, the additional data from interval training studies would suggest that higher intensity may be superior in terms of increases in Wpeak . Future studies should focus on establishing a threshold and an optimal training intensity for COPD.

Oxygen desaturation and adverse events during 6-min walk testing in patients with COPD.

BACKGROUND AND OBJECTIVE: The 6-min walk test (6MWT) is a simple test assessing functional capacity, but concerns about risks of substantial oxygen desaturation in pulmonary patients have led to non-adherence to the standardised American Thoracic Society guideline. We evaluated the safety of the 6MWT in stable COPD patients and compared the incidence of adverse events in patients with and without substantial exertional hypoxaemia. METHODS: 6MWT data were obtained for 1136 patients with moderate to very severe COPD. Demographics, adverse events, oxygen saturation (SpO2), 6-min walk distance, lung function and quality of life measures were compared between patients with substantial exertional hypoxaemia (nadir SpO2 < 85%) and those without (SpO2 ≥ 85%). Comparisons were made using Mann-Whitney U-test for continuous variables and Fisher's exact test for categorical variables. RESULTS: Twenty-five patients (2.2%) had adverse events, the most common being dizziness, chest tightness, chest pain and palpitations. Substantial exertional hypoxaemia did not increase the incidence of adverse events. No significant morbidity or mortality was recorded. Patients with adverse events had lower baseline SpO2, worse quality of life scores, and higher depression and anxiety scores. However, no significant differences were seen in anthropometric data, spirometric values or SpO2 during and after the 6MWT. CONCLUSIONS: Asymptomatic exertional hypoxaemia is not associated with an increased incidence of adverse events during 6MWT in COPD patients. Our data support the ATS guideline that the 6MWT should be continued in the absence of symptoms and that intermittent oximetry monitoring does not assist in preventing adverse events.

The relationship between fat-free mass index and pulmonary hyperinflation in COPD patients.

BACKGROUND AND OBJECTIVE: Reduced fat-free mass (FFM), a common finding in chronic obstructive pulmonary disease (COPD), may indirectly impact peak exercise capacity through a greater level of pulmonary hyperinflation. We aimed to investigate if FFM index (FFM/squared height) impacts exercise induced dynamic hyperinflation in COPD patients. METHODS: Fifty-four patients with moderate-to-very severe COPD performed a symptom limited incremental cardiopulmonary exercise tests with serial measurements of inspiratory capacity (IC). FFM was measured by whole-body bioelectrical impedance. RESULTS: Patients were 66.7 ± 7.7 years old with mean forced expiratory volume in 1 s (FEV1) of 1.08 ± 0.41 L (42 ± 15% of predicted). Peak exercise IC was significantly (P < 0.05) correlated with IC at rest (r = 0.78), FEV1(r = 0.66), FVC (r = 0.59), FFM (r = 0.38) and FFM index (r = 0.29). However, only FEV1 and rest IC predict peak IC (r = 0.86; P < 0.01) in a multivariate linear regression analysis. CONCLUSIONS: FFM index was weakly associated with peak exercise IC in COPD patients. However, it ceased to be an independent predictor when corrected for expiratory airflow limitation (FEV1) and lung hyperinflation at rest (rest IC).

Gas Exchange Impairment During COVID-19 Recovery.

BACKGROUND: Persistent impairment of pulmonary function and exercise capacity has been known to last for months or even years in the survivors who recovered from other coronavirus pneumonia. Some reports showed that subjects with coronavirus disease 2019 pneumonia after being discharged could have several sequelae, but there are few studies on gas exchange and exercise capacity complications in these subjects. AIMS: To describe residual gas exchange abnormalities during recovery from coronavirus disease 2019 pneumonia. METHODS: In an observational study, ∼90 d after onset of disease, we scheduled almost 200 subjects for an out-patient visit with pulmonary function testing and computed tomography of the lungs. Lung mechanics by using body plethysmography, gas exchange with diffusing lung capacity for carbon monoxide determined by the single-breath technique (DLCOsb) and diffusing lung capacity for nitric oxide determined by the single-breath technique (DLNOsb), and exercise ability by using the 6-min walk test (6MWT) were measured in the subjects. The results were compared between those who required invasive mechanical ventilation and those who did not. RESULTS: A total of 171 subjects were included, the majority (96%) had signs of residual pneumonia (such as an excess of high attenuation areas) on computed tomography of the lungs. The DLCOSB results were below the lower limit of the normal range in 29.2% of the subjects; during the 6MWT, 67% experienced oxygen desaturation ([Formula: see text]) > 4%; and, in 81 (47%), the dropped below 88%. Subjects who required invasive mechanical ventilation (49.7%) were more likely to have lower lung volumes, more gas exchange abnormality, less exercise capacity and more radiologic abnormality. CONCLUSIONS: Subjects who recovered from severe COVID-19 pneumonia continued to have abnormal lung function and abnormal radiologic findings.

Effect of a Graduated Walking Program on the Severity of Obstructive Sleep Apnea Syndrome. A Randomized Clinical Trial.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a common disease. The objective of this research was to determine the effectiveness of a graduated walking program in reducing the apnea-hypopnea index number in patients with obstructive sleep apnea syndrome (OSAS). METHODS: A randomized controlled clinical trial with a two-arm parallel in three tertiary hospitals was carried out with seventy sedentary patients with moderate to severe OSAS. Twenty-nine subjects in each arm were analyzed by protocol. The control group received usual care, while usual care and an exercise program based on progressive walks without direct supervision for 6 months were offered to the intervention group. RESULTS: The apnea-hypopnea index decreased by six points in the intervention group, and improvements in oxygen desaturation index, total cholesterol, and Low-Density Lipoprotein of Cholesterol (LDL-c) were observed. A higher decrease in sleep apnea-hypopnea index (45 ± 20.6 vs. 34 ± 26.3/h; p = 0.002) was found in patients with severe vs. moderate OSAS, as well as in oxygen desaturation index from baseline values (43.3 vs. 34.3/h; p = 0.046). Besides, High-Density Lipoprotein of Cholesterol (HDL-c) values showed a higher increase in the intervention group (45.3 vs. 49.5 mg/dL; p = 0.009) and also, a higher decrease in LDL-c was found in this group (141.2 vs. 127.5 mg/dL; p = 0.038). CONCLUSION: A home physical exercise program is a useful and viable therapeutic measure for the management of OSAS.

The likelihood of improving physical activity after pulmonary rehabilitation is increased in patients with COPD who have better exercise tolerance.

PURPOSE: Pulmonary rehabilitation (PR) enhances exercise tolerance in patients with COPD; however, improvements in physical activity (PA) are not guaranteed. This study explored the relationship between baseline exercise tolerance and changes in PA after PR. MATERIALS AND METHODS: Patient data from prospective clinical trials in the PR settings of Athens and Leuven (2008-2016) were analyzed. Validated PA monitors were worn for 1 week before and after a 12-week program. The proportion of patients who improved PA levels ≥1,000 steps/day ("PA responders") after PR was compared between those with initial 6-minute walk distance [6MWDi] <350 m and ≥350 m. Baseline predictors of PA change were evaluated via univariate and multivariate logistic regression analyses. RESULTS: Two hundred thirty-six patients with COPD (median [IQR] FEV1 44 [33-59] % predicted, age 65±8 years, 6MWDi 416 [332-486] m) were included. The proportion of "PA responders" after PR was significantly greater in those with higher vs lower 6MWDi (37.9% vs 16.4%, respectively; P<0.001). 6MWDi group classification was the strongest baseline independent predictor of PA improvement (univariate OR 3.10, 95% CI 1.51-6.36). CONCLUSION: The likelihood of improving PA after PR is increased with greater 6MWDi. Baseline exercise tolerance appears as an important stratification metric for future research in this field.

Validation of 4-meter-gait-speed test and 5-repetitions-sit-to-stand test in patients with pulmonary fibrosis: a clinimetric validation study.

Background and objective: Patients with pulmonary fibrosis (PF) have a clear exercise intolerance. The 4-meter-gait-speed (4MGS) test and the 5-repetitions-sit-to-stand (5STS) test are easy, inexpensive and reliable measures of functional performance. Both tests have been validated in healthy adults and patients with chronic obstructive pulmonary disease. 4MGS test and 5STS test have not been studied in patients with PF. Methods: In this cross-sectional clinimetric validation study 51 PF patients conducted in random order the 4MGS test, 5STS test and the 6-min walk test (6MWT) on a single day. Additionally, body weight, height, lean body mass, health-related quality of life, disease severity, handgrip strength, dyspnoea and leg fatigue were assessed. The setting was a tertiary referral center for Interstitial Lung Diseases. Results: Patients had a diagnosis of idiopathic pulmonary fibrosis (IPF, 37%), PF other than IPF (47%), or unclassified (16%). Patients walked 453±111m in six minutes. Moreover, it took the patients 2.0±0.5s to walk 4 m, and 12.0±3.8s for the 5STS test. The 4MGS test (r = 0.77; p<0.01) and the 5STS test (r = -0.41; p<0.01) correlated significantly with the distance walked in 6MWT. Indeed, 4MGS combined with handgrip strength and Medical Research Council dyspnoea grade could explain 75% of the variance in 6MWD. Conclusions: 4-meter-gait-speed and 5-repetitions sit-to-stand are significantly and independently correlated with the 6-minute walk distance in patients with pulmonary fibrosis. Indeed, 4-meter-gait-speed test may serve as a simple initial field test to assess exercise performance in patients with pulmonary fibrosis. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 317-326).

Primary graft dysfunction: Long-term physical function outcomes among lung transplant recipients.

BACKGROUND: Adults with primary graft dysfunction (PGD) after lung transplantation are at increased risk for pulmonary and functional impairment. No prior studies have described the long-term (within 1.5 years of transplant) cardiopulmonary exercise testing (CPET) results in adults with grade 3 PGD. The objective of this study was to compare the functional outcomes of lung transplant patients with and without grade 3 PGD via CPET and six-minute talk tests (6MWD). METHODS: 243 adults underwent lung transplantation between 2003 and 2010, 128 (53%) of whom underwent CPET and 6MWD within 12-18 months of transplantation. The primary measure of exposure was grade 3 PGD at 72 h, however grade 3 PGD within 72 h was also assessed. In addition, the impact of potential confounding variables was explored. RESULTS: Approximately one-third (32%) of the 243 patients experienced grade 3 PGD within 72 h; among these, 15 (6%) had grade 3 PGD at the 72 h time point. There were no differences in CPET or 6MWD between those with and without grade 3 PGD at 72 h despite a longer length of hospital stay and lower pulmonary function. Similar results were seen for patients with and without grade 3 PGD within 72 h, with the exception of a lower heart rate on CPET. CONCLUSIONS: Participants with grade 3 PGD are able to achieve functional outcomes comparable to those without PGD.