Prescribing and adjusting exercise training in chronic respiratory diseases – Expert-based practical recommendations

Background International guidelines recommend endurance (ET) and strength training (ST) in patients with chronic respiratory diseases (CRDs), but only provide rough guidance on how to set the initial training load. This may unintentionally lead to practice variation and inadequate training load adjustments. This study aimed to develop practical recommendations on tailoring ET and ST based on practices from international experts from the field of exercise training in CRDs. Methods 35 experts were invited to address a 64-item online survey about how they prescribe and adjust exercise training. Results Cycling (97%) and walking (86%) were the most commonly implemented ET modalities. Continuous endurance training (CET, 83%) and interval endurance training (IET, 86%) were the frequently applied ET types. Criteria to prescribe IET instead of CET were: patients do not tolerate CET due to dyspnoea at the initial training session (79%), intense breathlessness during initial exercise assessment (76%), and/or profound exercise-induced oxygen desaturation (59%). For ST, most experts (68%) recommend 3 sets per exercise; 62% of experts set the intensity at a specific load that patients can tolerate for a range of 8 to 15 repetitions per set. Also, 56% of experts advise patients to approach local muscular exhaustion at the end of a single ST set. Conclusions The experts´ practices were summarized to develop practical recommendations in the form of flowcharts on how experts apply and adjust CET, IET, and ST in patients with CRDs. These recommendations may guide health care professionals to optimize exercise training programs in patients with CRDs

Vergleich von vier baugleichen elektronischen Nasen und drei Messaufbauten

Background: Volatile organic compounds (VOCs) can be used as biomarkers in exhaled air. VOC profiles can be detected by an array of nanosensors of an electronic nose. These profiles can be analysed using bioinformatics. It is, however, not known whether different devices of the same model measure identically and to which extent different set-ups and the humidity of the inhaled air influence the VOC profile. Methods: Three different measuring set-ups were designed and three healthy control subjects were measured with each of them, using four devices of the same model (Cyranose 320™, Smiths Detection). The exhaled air was collected in a plastic bag. Either ambient air was used as reference (set-up Leipzig), or the reference air was humidified (100 % relative humidity) (set-up Marburg and set-up Munich). In the set-up Marburg the subjects inhaled standardised medical air (Aer medicinalis Linde, AGA AB) out of a compressed air bottle through a demand valve; this air (after humidification) was also used as reference. In the set-up Leipzig the subjects inhaled VOC-filtered ambient air, in the set-up Munich unfiltered room air. The data were evaluated using either the real-time data or the changes in resistance as calculated by the device. Results: The results were clearly dependent on the set-up. Apparently, humidification of the reference air could reduce the variance between devices, but this result was also dependent on the evaluation method used. When comparing the three subjects, the set-ups Munich and Marburg mapped these in a similar way, whereas not only the signals but also the variance of the set-up Leipzig were larger. Conclusion: Measuring VOCs with an electronic nose has not yet been standardised and the set-up significantly affects the results. As other researchers use further methods, it is currently not possible to draw generally accepted conclusions. More systematic tests are required to find the most sensitive and reliable but still feasible set-up so that comparability is improved

Outpatient Pulmonary Rehabilitation in Patients with Long COVID Improves Exercise Capacity, Functional Status, Dyspnea, Fatigue, and Quality of Life

Background: COVID-19 survivors face the risk of long-term sequelae including fatigue, breathlessness, and functional limitations. Pulmonary rehabilitation has been recommended, although formal studies quantifying the effect of rehabilitation in COVID-19 patients are lacking. Methods: We conducted a prospective observational cohort study including consecutive patients admitted to an outpatient pulmonary rehabilitation center due to persistent symptoms after COVID-19. The primary endpoint was change in 6-min walk distance (6MWD) after undergoing a 6-week interdisciplinary individualized pulmonary rehabilitation program. Secondary endpoints included change in the post-COVID-19 functional status (PCFS) scale, Borg dyspnea scale, Fatigue Assessment Scale, and quality of life. Further, changes in pulmonary function tests were explored. Results: Of 64 patients undergoing rehabilitation, 58 patients (mean age 47 years, 43% women, 38% severe/critical COVID-19) were included in the per-protocol-analysis. At baseline (i.e., in mean 4.4 months after infection onset), mean 6MWD was 584.1 m (+/- 95.0), and functional impairment was graded in median at 2 (IQR, 2-3) on the PCFS. On average, patients improved their 6MWD by 62.9 m (+/- 48.2, p < 0.001) and reported an improvement of 1 grade on the PCFS scale. Accordingly, we observed significant improvements across secondary endpoints including presence of dyspnea (p < 0.001), fatigue (p < 0.001), and quality of life (p < 0.001). Also, pulmonary function parameters (forced expiratory volume in 1 s, lung diffusion capacity, inspiratory muscle pressure) significantly increased during rehabilitation. Conclusion: In patients with long COVID, exercise capacity, functional status, dyspnea, fatigue, and quality of life improved after 6 weeks of personalized interdisciplinary pulmonary rehabilitation. Future studies are needed to establish the optimal protocol, duration, and long-term benefits as well as cost-effectiveness of rehabilitation.Thrombosis and Hemostasi

Hydrogen peroxide in exhaled air: A source of error, a paradox and its resolution.

The concentration of hydrogen peroxide (H2O2) in exhaled air has been reported to be elevated in asthma and chronic obstructive pulmonary disease (COPD), but results are inconsistent and difficult to reproduce. As H2O2 occurs in ambient air, we examined its association with exhaled H2 O2 in human subjects. Exhaled breath condensate (EBC) of 12 COPD patients and nine healthy control subjects was collected either with an inhalation filter (efficiency 81%) or without. Ambient air condensate (AAC) was collected in parallel and samples were analysed for H2O2. Additionally, ambient H2O2 was recorded by an atmospheric measuring device (online fluorometric measurement). H2 O2 concentration in AAC was significantly higher (p&lt;0.001) than in EBC. AAC variations were concordant with the data from the atmospheric measuring instrument. In both subjects&rsquo; groups, the inhalation filter reduced H2O2 values (p&lt;0.01). Despite generally low levels in exhaled air, analysis by a mathematical model revealed a contribution from endogenous H2O2 production. The low H2O2 levels in exhaled air are explained by the reconditioning of H2O2-containing inhaled air in the airways. Inhaled H2O2 may be one factor in the heterogeneity and limited reproducibility of study results. A valid determination of endogenous H2 O2 production requires inhalation filters

Outpatient Pulmonary Rehabilitation in Patients with Long COVID Improves Exercise Capacity, Functional Status, Dyspnea, Fatigue, and Quality of Life

Background: COVID-19 survivors face the risk of long-term sequelae including fatigue, breathlessness, and functional limitations. Pulmonary rehabilitation has been recommended, although formal studies quantifying the effect of rehabilitation in COVID-19 patients are lacking. Methods: We conducted a prospective observational cohort study including consecutive patients admitted to an outpatient pulmonary rehabilitation center due to persistent symptoms after COVID-19. The primary endpoint was change in 6-min walk distance (6MWD) after undergoing a 6-week interdisciplinary individualized pulmonary rehabilitation program. Secondary endpoints included change in the post-COVID-19 functional status (PCFS) scale, Borg dyspnea scale, Fatigue Assessment Scale, and quality of life. Further, changes in pulmonary function tests were explored. Results: Of 64 patients undergoing rehabilitation, 58 patients (mean age 47 years, 43% women, 38% severe/critical COVID-19) were included in the per-protocol-analysis. At baseline (i.e., in mean 4.4 months after infection onset), mean 6MWD was 584.1 m (+/- 95.0), and functional impairment was graded in median at 2 (IQR, 2-3) on the PCFS. On average, patients improved their 6MWD by 62.9 m (+/- 48.2, p < 0.001) and reported an improvement of 1 grade on the PCFS scale. Accordingly, we observed significant improvements across secondary endpoints including presence of dyspnea (p < 0.001), fatigue (p < 0.001), and quality of life (p < 0.001). Also, pulmonary function parameters (forced expiratory volume in 1 s, lung diffusion capacity, inspiratory muscle pressure) significantly increased during rehabilitation. Conclusion: In patients with long COVID, exercise capacity, functional status, dyspnea, fatigue, and quality of life improved after 6 weeks of personalized interdisciplinary pulmonary rehabilitation. Future studies are needed to establish the optimal protocol, duration, and long-term benefits as well as cost-effectiveness of rehabilitation

Relationship between body composition, exercise capacity and health-related quality of life in idiopathic pulmonary fibrosis

Introduction Bioelectrical impedance analysis (BIA) can be used to estimate Fat-Free Mass Index (FFMI). However, the use of directly measured BIA variables, such as phase angle (PhA), has gained attention. The frequency of low FFMI and PhA and its associations with exercise capacity and health-related quality of life (HRQL) in patients with idiopathic pulmonary fibrosis (IPF) have been scarcely studied.Objectives To investigate the frequency of low FFMI and PhA and their associations with exercise capacity and HRQL in patients with IPF.Methods Patients underwent assessment of lung function, body composition, exercise capacity by the 6 min walk distance (6MWD), and HRQL by the Medical Outcomes Study Short-Form 36-item Questionnaire (SF-36). Patients were classified as presenting normal or low PhA or FFMI, accordingly to the 10th percentiles of age-sex-body mass index (BMI)-specific reference values.Results 98 patients (84 males, age: 68 +/- 8 years, forced vital capacity: 64%+/- 18%predicted) were included. 24 patients presented low PhA. They were characterised by worse lung function, exercise capacity and HRQL compared with patients with normal PhA. 10 patients presented low FFMI, but despite differences in body composition, no differences were found between these patients and patients with normal FFMI. In a single regression analysis, age, lung function and body composition variables (except FFMI) were related to 6MWD and SF-36 Physical Summary Score (R-2=0.06-0.36, p&lt;0.05). None of the variables were related to SF-36 Mental Summary Score.Conclusion One-fourth of the patients with IPF with normal to obese BMI present abnormally low PhA. Patients classified as low PhA presented worse lung function, exercise capacity and HRQL

Short-term effects of comprehensive pulmonary rehabilitation and its maintenance in patients with idiopathic pulmonary fibrosis: A randomized controlled trial.

The recommendation for pulmonary rehabilitation (PR) in idiopathic pulmonary fibrosis (IPF) is weak with low-quality evidence. Therefore, the aim of this study is to investigate short-term PR effects and their maintenance after a 3-month follow-up. Fifty-four IPF patients were randomized into a group receiving a 3-week comprehensive, inpatient PR (n = 34, FVC: 74 +/- 19% pred.) or usual care (UC) (n = 17, FVC: 72 +/- 20%pred.). Outcomes were measured at baseline (T1), after intervention (T2), and 3 months after T2 (T3). A 6-min walk distance (6MWD) was used as the primary outcome and chronic respiratory disease questionnaire (CRQ) scores as the secondary outcome. Change in 6MWD from T1 to T2 (Delta = 61 m, 95% CI (18.5-102.4), p = 0.006) but not from T1 to T3 (Delta = 26 m, 95% CI (8.0-61.5), p = 0.16) differed significantly between groups. Higher baseline FVC and higher anxiety symptoms were significant predictors of better short-term 6MWD improvements. For the change in CRQ total score, a significant between-group difference from T1 to T2 (Delta = 3.0 pts, 95% CI (0.7-5.3), p = 0.01) and from T1 to T3 (Delta = 3.5 pts, 95% CI (1.5-5.4), p = 0.001) was found in favour of the PR group. To conclude, in addition to the short-term benefits, inpatient PR is effective at inducing medium-term quality of life improvements in IPF. PR in the early stages of the disease seems to provoke the best benefits