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Background: This study aimed to determine the value of phase angle (PhA) in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH) and its association with nutritional and functional parameters., Methods: A cross-sectional study of 77 patients under follow-up at the pulmonary outpatient clinic of a public hospital. Anthropometric measurements and functional assessments of physical and pulmonary capacity were performed, and a regular physical activity questionnaire was administered., Results: The sample consisted of 38 patients with COPD (mean age, 63.8 ± 9.9 years; 68.4% female) and 39 patients with PH (mean age, 46.6 ± 14.4 years; 79.5% female). There was no difference in anthropometric measurements between patients with COPD and PH. Patients with COPD had mild to moderate limitations of pulmonary function, while patients with PH had only mild limitations (p < 0.01). Although the median distance covered in the 6-minute walk test (6MWT) was different between the COPD and PH groups (p < 0.05), it was considered adequate for these populations. Mean PhA was within the range considered adequate in patients with COPD (6.3°±1°) and PH (6.2°±0.8°) (p > 0.05). In the statistical analyses, although the correlations were weak, adequate PhA correlated with fat free mass index, 6MWT, disease staging, forced vital capacity, and forced expiratory volume in the first second., Conclusion: The anthropometric profile of both patient groups was very similar, and PhA values were within the expected range. Despite weak correlations, PhA is a clinical component to be followed and investigated in patients with lung disease.

Background: Expiratory flow limitation (EFL) is a key physiological abnormality in COPD. Comparing tidal-to-maximum flow-volume (F-V) loops is a simple and widely available method to assess EFL in patients with COPD. We aimed to investigate whether subjects with COPD showing significant resting tidal F-V enveloping (ie, > 50% tidal volume) would present with higher exertional operating lung volumes, which would lead to greater burden of dyspnea and poorer exercise tolerance compared to their counterparts., Methods: 37 subjects with COPD (21 males; 63.1 ± 9.2 years old; FEV 1 = 37 ± 12% predicted) and 9 paired controls (3 males; 55.9 ± 11.7 y old) performed an incremental cardiopulmonary exercise testing on a cycle ergometer. Dyspnea perception, inspiratory capacity maneuvers after 3-4 sequential tidal F-V loops, and esophageal and gastric pressures were measured during exercise., Results: Most subjects (31 of 37, 84%) presented with significant tidal F-V enveloping. Critical inspiratory constraints and upward dyspnea inflection points (as a function of both work rate and ventilation) were reached earlier in these subjects, thereby leading to poorer exercise tolerance compared to their counterparts ( P = .01). Abdominal muscle recruitment (ie, increase in gastric pressure ≥ 15%) during tidal expiration was significantly higher in the EFL+ group. However, this did not bear an influence on the operating lung volumes, inspiratory constraints, dyspnea, cardiocirculatory responses, or exercise tolerance ( P > .05)., Conclusions: Tidal F-V loop enveloping at rest should be valued as it is related to relevant clinical outcomes, such as dyspnea burden and exercise tolerance in subjects with COPD., (Copyright © 2019 by Daedalus Enterprises.)

Combining measurements of impaired lung mechanics (inspiratory constraints) with an index of increased respiratory stimuli to metabolic demand (poor ventilatory efficiency) might enhance the ability of cardiopulmonary exercise testing (CPET) in exposing a mechanistic role for ventilation on exertional dyspnea in COPD. In addition to the standard approach to suggest ventilatory limitation to exercise - a low breathing reserve (1-(peak ventilation (V̇E)/maximal voluntary ventilation × 100 < 20%) - we assessed the presence of critical inspiratory constraints (end-inspiratory lung volume (EILV)/total lung capacity (TLC) ≥ 0.9) and ventilatory inefficiency (V̇E/CO 2 output (V̇CO 2 ) nadir > 34) in 288 patients with mild to very severe COPD (FEV 1 ranging from 18 to 121% predicted). We found that ∼50% of the patients with preserved breathing reserve developed critical inspiratory constraints. A low breathing reserve was weakly related to a lower peak O 2 uptake (V̇O 2 ) and/or a higher dyspnea burden; for instance, patients with low breathing reserve but without critical inspiratory constraints had similar dyspnea and peak V̇O 2 than those with preserved breathing reserve ( p  > 0.05). In contrast, critical inspiratory constraints and ventilatory inefficiency were strongly associated with a negative outcome (likelihood ratio = 42.3 and 47.7, respectively; p  < 0.001). A multiple logistic regression analysis revealed that only EILV/TLC ≥ 0.9 and V̇E/V̇CO 2 nadir >34 predicted a severely reduced peak V̇O 2 due to a high dyspnea burden ( p  < 0.001). Measurements of dynamic mechanical constraints and ventilatory inefficiency during incremental CPET are key to determine the impact of COPD on dyspnea and exercise tolerance across the spectrum of disease severity.

Interval exercise delays critical mechanical-ventilatory constraints with positive consequences on Dyspnoea and exercise tolerance in COPD. We hypothesized that those advantages of interval exercise would be partially off-set in patients showing excessive ventilation (V˙E) to metabolic demand (V˙CO 2 ). Sixteen men (FEV 1  = 42.3 ± 8.9%) performed, on different days, 30 s and 60 s bouts at 100% peak (on) interspersed by moderate exercise at 40% (off). Nine patients did not sustain exercise for 30 min irrespective of on duration. They presented with higher V˙E/V˙CO 2 nadir (35 ± 3 vs. 30 ± 5) and dead space/tidal volume (0.39 ± 0.05 vs. 0.34 ± 0.06) compared to their counterparts (p < 0.05). [Lactate], operating lung volumes and symptom burden (dyspnoea and leg effort) were also higher (p < 0.05). Unloading off decreased the metabolic-ventilatory demands, thereby allowing 7/9 patients to exercise for 30 min. Increased wasted ventilation accelerates the rate at which critical mechanical constraints and limiting dyspnoea are reached during interval exercise in patients with COPD., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Rationale: An increased ventilatory response to exertional metabolic demand (high [Formula: see text]e/[Formula: see text]co 2 relationship) is a common finding in patients with coexistent chronic obstructive pulmonary disease and heart failure., Objectives: We aimed to determine the mechanisms underlying high [Formula: see text]e/[Formula: see text]co 2 and its impact on operating lung volumes, dyspnea, and exercise tolerance in these patients., Methods: Twenty-two ex-smokers with combined chronic obstructive pulmonary disease and heart failure with reduced left ventricular ejection fraction undertook, after careful treatment optimization, a progressive cycle exercise test with capillary (c) blood gas collection., Measurements and Main Results: Regardless of the chosen metric (increased [Formula: see text]e-[Formula: see text]co 2 slope, [Formula: see text]e/[Formula: see text]co 2 nadir, or end-exercise [Formula: see text]e/[Formula: see text]co 2 ), ventilatory inefficiency was closely related to Pc CO 2 (r values from -0.80 to -0.84; P < 0.001) but not dead space/tidal volume ratio. Ten patients consistently maintained exercise Pc CO 2 less than or equal to 35 mm Hg (hypocapnia). These patients had particularly poor ventilatory efficiency compared with patients without hypocapnia (P < 0.05). Despite the lack of between-group differences in spirometry, lung volumes, and left ventricular ejection fraction, patients with hypocapnia had lower resting Pa CO 2 and lung diffusing capacity (P < 0.01). Excessive ventilatory response in this group was associated with higher exertional Pc O 2 . The group with hypocapnia, however, had worse mechanical inspiratory constraints and higher dyspnea scores for a given work rate leading to poorer exercise tolerance compared with their counterparts (P < 0.05)., Conclusions: Heightened neural drive promoting a ventilatory response beyond that required to overcome an increased "wasted" ventilation led to hypocapnia and poor exercise ventilatory efficiency in chronic obstructive pulmonary disease-heart failure overlap. Excessive ventilation led to better arterial oxygenation but at the expense of earlier critical mechanical constraints and intolerable dyspnea.

Introduction: The application of expiratory positive airway pressure (EPAP) in patients with COPD during exercise may reduce dynamic hyperinflation, while, on the other hand, it can increase the resistive work of breathing. Therefore, we evaluated the effects of 2 intensities of EPAP during exercise on tolerance, dynamic hyperinflation, and dyspnea in subjects with moderate to very severe COPD., Methods: We performed a cross-sectional, experimental, 4-visit study. In visit 1, subjects performed symptom-limited cycling incremental cardiopulmonary exercise test (CPET). In visits 2-4, at least 48 h apart, in a randomized order, subjects performed constant CPET without EPAP, EPAP with 5 cm H 2 O (EPAP5), or EPAP with 10 cm H 2 O (EPAP10)., Results: The study included 15 non-hypoxemic subjects ranging from moderate to very severe COPD (mean FEV 1 = 35 ± 11% predicted). Increasing intensities of EPAP during constant CPET tended to cause progressive reduction in exercise tolerance ( P = .11). Of note, 10 of 15 subjects demonstrated significantly shorter average exercise duration with EPAP10 compared to the test without EPAP (-151 ± 105 s, P = .03 or -41 ± 26%). Minute ventilation increment was constrained by EPAP, secondary to a limited increase in tidal volume ( P = .01). Finally, dyspnea sensation and serial measurements of inspiratory capacity during exercise were similar when comparing the three interventions at isotime and at end-constant CPETs., Conclusions: The application of EPAP5 or EPAP10 during exercise tended to cause a progressive reduction in exercise tolerance in subjects with COPD without improvement in dyspnea or dynamic hyperinflation at equivalent exercise duration., (Copyright © 2017 by Daedalus Enterprises.)

Exertional dyspnea is present across the spectrum of chronic obstructive pulmonary disease (COPD) severity. However, without realizing it themselves, patients may decrease daily physical activity to avoid distressing respiratory sensations. Dyspnea also may be associated with deconditioning. Cardiopulmonary exercise testing can uncover exertional dyspnea and its physiological determinants in patients with preserved or only mildly reduced FEV 1 . Dyspnea in mild COPD can largely be explained by increased "wasted" ventilation in the physiological dead space, which heightens the drive to breathe and worsens the inspiratory mechanical constraints. During incremental exercise testing, this is readily identified as an excessive ventilation-to-metabolic demand, that is, a high ventilation ([Formula: see text]e) to carbon dioxide output ([Formula: see text]co 2 ) relationship. Linking increases in [Formula: see text]e/[Formula: see text]co 2 to exertional dyspnea may provide objective evidence that a patient's poor exercise tolerance is not just a consequence of deconditioning. This information should prompt a proactive therapeutic approach to increase the available ventilatory reserve by, for example, giving inhaled bronchodilators. Considering that the structural determinants of ventilatory inefficiency (early emphysema, ventilation-perfusion mismatching, and microvascular disease) may progress despite only modest changes in FEV 1 , serial [Formula: see text]e/[Formula: see text]co 2 measurements might also prove valuable to track disease progression in these symptomatic patients.

Exercise ventilation ( V ' E ) relative to carbon dioxide output ( V ' CO 2 ) is particularly relevant to patients limited by the respiratory system, e.g. those with chronic obstructive pulmonary disease (COPD). High V ' E - V ' CO 2 (poor ventilatory efficiency) has been found to be a key physiological abnormality in symptomatic patients with largely preserved forced expiratory volume in 1 s (FEV 1 ). Establishing an association between high V ' E - V ' CO 2 and exertional dyspnoea in mild COPD provides evidence that exercise intolerance is not a mere consequence of detraining. As the disease evolves, poor ventilatory efficiency might help explaining "out-of-proportion" breathlessness (to FEV 1 impairment). Regardless, disease severity, cardiocirculatory co-morbidities such as heart failure and pulmonary hypertension have been found to increase V ' E - V ' CO 2 In fact, a high V ' E - V ' CO 2 has been found to be a powerful predictor of poor outcome in lung resection surgery. Moreover, a high V ' E - V ' CO 2 has added value to resting lung hyperinflation in predicting all-cause and respiratory mortality across the spectrum of COPD severity. Documenting improved ventilatory efficiency after lung transplantation and lung volume reduction surgery provides objective evidence of treatment efficacy. Considering the usefulness of exercise ventilatory efficiency in different clinical scenarios, the V ' E - V ' CO 2 relationship should be valued in the interpretation of cardiopulmonary exercise tests in patients with mild-to-end-stage COPD., (Copyright ©ERS 2017.)

Background: Exercise oscillatory ventilation (EOV) is associated with poor ventilatory efficiency and higher operating lung volumes in heart failure. These abnormalities may be particularly deleterious to dyspnea and exercise tolerance in mechanically-limited patients, e.g. those with coexistent COPD., Methods: Ventilatory, gas exchange and sensory responses to incremental exercise were contrasted in 68 heart failure-COPD patients (12 EOV+). EOV was established by standard criteria., Results: Compared to EOV-, EOV+ had lower exercise capacity, worse ventilatory inefficiency and higher peak dyspnea scores (p<0.05). Peak capillary PCO 2 (PcCO 2 ) was higher and end-tidal CO 2 (PETCO 2 ) was lower in EOV+. Thus, greater (i.e., more positive) P(c-ET)CO 2 and dead space/tidal volume values were found in these patients compared to EOV- (p<0.05). Ventilatory inefficiency was related to increased dead space/tidal volume in EOV+ (r=0.74; p<0.01). Owing to higher operating lung volumes, inspiratory reserve volume (IRV) decreased to a greater extent in EOV+. Tidal volume oscillations consistently ceased when a "critical" IRV was reached (~0.3-0.5L); thereafter, PcCO 2 stabilized or increased and dyspnea scores rose sharply. Exercise capacity was closely related to IRV decrements and peak dyspnea in EOV+ (r=-0.78 and 0.84, respectively; p<0.01)., Conclusions: Dyspnea and exercise tolerance are negatively influenced by EOV in heart failure patients presenting with COPD as co-morbidity. Pharmacological and non-pharmacological interventions known to decrease EOV might prove particularly valuable to mitigate symptom burden and exercise intolerance in this specific heart failure group., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To investigate whether the opposite effects of heart failure (HF) and chronic obstructive pulmonary disease (COPD) on exercise ventilatory inefficiency (minute ventilation [(Equation is included in full-text article.)E]-carbon dioxide output [(Equation is included in full-text article.)CO2] relationship) would negatively impact its prognostic relevance., Methods: After treatment optimization and an incremental cardiopulmonary exercise test, 30 male patients with HF-COPD (forced expiratory volume in 1 second [FEV1] = 57% ± 17% predicted, ejection fraction = 35% ± 6%) were prospectively followed up during 412 ± 261 days for major cardiac events., Results: Fourteen patients (46%) had a negative outcome. Patients who had an event had lower echocardiographically determined right ventricular fractional area change (RVFAC), greater ventilatory inefficiency (higher (Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2 nadir), and lower end-tidal CO2 (PETCO2) (all P < .05). Multivariate Cox models revealed that (Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2 nadir >36, ΔPETCO2(PEAK-REST)≥2 mm Hg, and PETCO2PEAK≤33 mm Hg added prognostic value to RVFAC≤45%. Kaplan-Meyer analyses showed that although 18% of patients with RVFAC>45% had a major cardiac event after 1 year, no patient with RVFAC>45% and (Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2 nadir ≤36 (or PETCO2PEAK>33 mm Hg) had a negative event. Conversely, although 69% of patients with RVFAC≤45% had a major cardiac event after 1 year, all patients with RVFAC≤45% and ΔPETCO2(PEAK-REST)≥2 mm Hg had a negative event., Conclusion: Ventilatory inefficiency remains a powerful prognostic marker in HF despite the presence of mechanical ventilatory constraints induced by COPD. If these preliminary findings are confirmed in larger studies, optimal thresholds for outcome prediction are likely greater than those traditionally recommended for HF patients without COPD.

Objective:: To compare a once-daily long-acting β2 agonist (indacaterol 150 µg) with a once-daily long-acting anticholinergic (tiotropium 5 µg) in terms of their effects on exercise endurance (limit of tolerance, Tlim) in patients with moderate COPD. Secondary endpoints were their effects on lung hyperinflation, exercise-related dyspnea, and daily-life dyspnea., Methods:: This was a randomized, single-blind, crossover pilot study involving 20 patients (mean age, 60.9 ± 10.0 years; mean FEV1, 69 ± 7% of predicted). Spirometric parameters, Transition Dyspnea Index scores, Tlim, and exertional dyspnea were compared after three weeks of each treatment (with a one-week washout period between treatments)., Results:: Nineteen patients completed the study (one having been excluded because of COPD exacerbation). Improvement in Tlim from baseline tended to be greater after treatment with tiotropium than after treatment with indacaterol (96 ± 163 s vs. 8 ± 82 s; p = 0.06). Tlim significantly improved from baseline after treatment with tiotropium (having increased from 396 ± 319 s to 493 ± 347 s; p = 0.010) but not after treatment with indacaterol (having increased from 393 ± 246 to 401 ± 254 s; p = 0.678). There were no differences between the two treatments regarding improvements in Borg dyspnea scores and lung hyperinflation at "isotime" and peak exercise. There were also no significant differences between treatments regarding Transition Dyspnea Index scores (1.5 ± 2.1 vs. 0.9 ± 2.3; p = 0.39)., Conclusions:: In patients with moderate COPD, tiotropium tends to improve Tlim in comparison with indacaterol. No significant differences were observed between the two treatments regarding their effects on lung hyperinflation, exercise-related dyspnea, and daily-life dyspnea. Future studies, including a larger number of patients, are required in order to confirm our findings and explore mechanistic explanations. (ClinicalTrials.gov identifier: NCT01693003 [http://www.clinicaltrials.gov/])., Objetivo:: Comparar um β2-agonista de longa duração administrado uma vez por dia (indacaterol 150 µg) a um anticolinérgico de longa duração administrado uma vez por dia (tiotrópio 5 µg) quanto a seus efeitos na resistência ao exercício (limite de tolerância, Tlim) em pacientes com DPOC moderada. Os desfechos secundários foram seus efeitos na hiperinsuflação pulmonar, na dispneia causada pelo exercício e na dispneia na vida diária., Métodos:: Estudo piloto randomizado cruzado e simples cego com 20 pacientes (média de idade: 60,9 ± 10,0 anos; média do VEF1: 69 ± 7% do previsto). Parâmetros espirométricos, pontuação no Transition Dyspnea Index, Tlim e dispneia aos esforços foram comparados após três semanas de cada tratamento (com uma semana de intervalo entre os tratamentos)., Resultados:: Dezenove pacientes completaram o estudo - um foi excluído por causa de exacerbação da DPOC. A melhora no Tlim tendeu a ser maior com tiotrópio do que com indacaterol (96 ± 163 s vs. 8 ± 82 s; p = 0,06). Em comparação com os valores basais, o Tlim melhorou significativamente com tiotrópio (aumentando de 396 ± 319 s para 493 ± 347 s; p = 0,010), mas não com indacaterol (aumentando de 393 ± 246 para 401 ± 254 s; p = 0,678). Não houve diferença entre os tratamentos quanto à melhora na pontuação na escala de dispneia de Borg e na insuflação pulmonar no "isotempo" e no pico do exercício. Também não houve diferenças significativas entre os tratamentos quanto à pontuação no Transition Dyspnea Index (1,5 ± 2,1 vs. 0,9 ± 2,3; p = 0,39)., Conclusões:: Em pacientes com DPOC moderada, o tiotrópio tende a melhorar o Tlim em comparação com o indacaterol. Não houve diferenças significativas entre os tratamentos quanto a seus efeitos na insuflação pulmonar, na dispneia durante o exercício e na dispneia na vida diária. São necessários mais estudos, com um número maior de pacientes, para confirmar nossos achados e explorar explicações mecanicistas. (ClinicalTrials.gov identifier: NCT01693003 [http://www.clinicaltrials.gov/]).

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)., (© 2014 Asian Pacific Society of Respirology.)

Background: Post-infectious bronchiolitis obliterans (PBO) is a chronic lung disease characterized by the persistence of continuous obstructive respiratory symptoms following an acute and severe respiratory infection in children under 3 years old. The purpose of the present study was to investigate if adolescents and adults with diagnosis of PBO have reduced aerobic capacity and identify factors related with exercise performance., Methods: A convenience sample of 16 patients (10-23 years) that have consulted with established diagnosis of PBO in a tertiary care clinic were studied. Fourteen healthy matched subjects were selected from the community to serve as controls. They performed resting lung function tests and cycle incremental cardiopulmonary exercise tests., Results: Peak aerobic capacity (peak V˙O(2)) was significantly lower in patients compared to controls (84 ± 15 vs. 101 ± 17% pred; P < 0.01). Peak V˙O(2) was correlated with rest inspiratory capacity (IC) (r = 0.60; P = 0.02) and marginally with forced expiratory volume in the first second (FEV(1)) (r = 0.45; P = 0.09). Additionally, FEV(1) was correlated with IC (r = 0.83; P < 0.01) and residual volume/total lung capacity (r = -0.91, P < 0.01)., Conclusions: Adolescent and adult patients with PBO had reduced peak V˙O(2) compared to healthy controls. Peak V˙O(2) was correlated with parameters of airflow limitation and rest hyperinflation. The greater the air flow limitation (lower FEV(1)) the greater the hyperinflation, air trapping, and aerobic capacity reduction., (© 2013 Wiley Periodicals, Inc.)

Objective: To investigate the modulatory effects that dynamic hyperinflation (DH), defined as a reduction in inspiratory capacity (IC), has on exercise tolerance after bronchodilator in patients with COPD., Methods: An experimental, randomized study involving 30 COPD patients without severe hypoxemia. At baseline, the patients underwent clinical assessment, spirometry, and incremental cardiopulmonary exercise testing (CPET). On two subsequent visits, the patients were randomized to receive a combination of inhaled fenoterol/ipratropium or placebo. All patients then underwent spirometry and submaximal CPET at constant speed up to the limit of tolerance (Tlim). The patients who showed ΔIC(peak-rest) < 0 were considered to present with DH (DH+)., Results: In this sample, 21 patients (70%) had DH. The DH+ patients had higher airflow obstruction and lower Tlim than did the patients without DH (DH-). Despite equivalent improvement in FEV1 after bronchodilator, the DH- group showed higher ΔIC(bronchodilator-placebo) at rest in relation to the DH+ group (p < 0.05). However, this was not found in relation to ΔIC at peak exercise between DH+ and DH- groups (0.19 ± 0.17 L vs. 0.17 ± 0.15 L, p > 0.05). In addition, both groups showed similar improvements in Tlim after bronchodilator (median [interquartile range]: 22% [3-60%] vs. 10% [3-53%]; p > 0.05)., Conclusions: Improvement in TLim was associated with an increase in IC at rest after bronchodilator in HD- patients with COPD. However, even without that improvement, COPD patients can present with greater exercise tolerance after bronchodilator provided that they develop DH during exercise.

Aim: Decrease in peripheral oxygen delivery may impact exercise performance in athletes with exercise-related arterial oxygen desaturation (ERD). We evaluated whether sodium bicarbonate ingestion would be effective to reduce ERD and what is the consequences upon exercise performance., Methods: Seventy highly trained athletes performed an incremental treadmill cardiopulmonary exercise test (incCPX) and a high intensity constant speed test (ctCPX) on separate days. Subjects who developed ERD by pulse oximetry were randomly allocated to oral sodium bicarbonate or placebo during 5 days. At the end of treatment subjects repeated both tests., Results: ERD prevalence was 33% during the incCPX (17 % severe, 48% moderate and 35% mild) and 34% (5 % severe, 37% moderate and 58% mild) in the ctCPX. Athletes who developed ERD have greater aerobic capacity (incCPX) and endurance time (ctCPX). Active treatment, but not placebo, reduced ERD during ctCPX (P<0.05). However, there were no significant positive effects on main parameters of aerobic function and endurance exercise capacity (P>0.05)., Conclusion: Sodium bicarbonate was effective in lessening ERD during ctCPX in athletes. However, this intervention failed to improve maximal and submaximal exercise capacity in these subjects.

Objective: To investigate the effectiveness of pulmonary rehabilitation (PR) in exercise capacity and quality of life in patients with chronic obstructive pulmonary disease (COPD) with and without global fat-free mass (FFM) depletion., Design: Retrospective case-control., Setting: Outpatient clinic, university center., Participants: COPD patients (N=102) that completed PR were initially evaluated., Intervention: PR including whole-body and weight training for 12 weeks, 3 times per week., Main Outcome Measures: St. George Respiratory Questionnaire (SGRQ), 6-minute walk distance (6MWD), and FFM evaluation applied before and after PR., Results: Patients were stratified according to their FFM status measured by bioelectric impedance. They were considered depleted if the FFM index was ≤ 15 kg/m(2) in women and ≤ 16 kg/m(2) in men. From the initial sample, all depleted patients (n=31) composed the FFM depleted group. It was composed predominantly by women (68%) with a mean age ± SD of 64.4 ± 7.3 years and a forced expiratory volume in 1 second of 33.6%=-13.2% predicted. Paired for sex and age, 31 nondepleted patients were selected from the initial sample to compose the nondepleted group. Improvement in the 6MWD was similar in these 2 groups after PR. Both groups improved SGRQ scores, although the observed power was small and did not allow adequate comparison between depleted and nondepleted patients. There was no difference between groups in weight change, whereas FFM tended to be greater in depleted patients. This increase had no correlation with the 6MWD or the SGRQ., Conclusions: Benefits of PR to exercise capacity were similar comparing FFM depleted and nondepleted COPD patients. Although FFM change tended to be greater in depleted patients, this increase had no definite relation with clinical outcomes., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To characterize the presence, extent, and patterns of dynamic hyperinflation (DH) during treadmill exercise testing in patients with moderate to severe COPD., Methods: This was a cross-sectional study involving 30 non-hypoxemic patients (FEV1= 43 ± 14% of predicted) who were submitted to a cardiopulmonary exercise test on a treadmill at a constant speed (70-80% of maximum speed) to the tolerance limit (Tlim). Serial inspiratory capacity (IC) maneuvers were used in order to assess DH., Results: Of the 30 patients studied, 19 (63.3%) presented with DH (DH+ group), having greater pulmonary function impairment at rest than did those without DH (DH- group). None of the variables studied correlated with exercise tolerance in the DH- group, whereas Tlim, IC, and perception of dyspnea during exercise did so correlate in the DH+ group (p < 0.05). In the DH+ group, 7 and 12 patients, respectively, presented with a progressive and a stable pattern of DH (ΔIC Tlim,2min = -0.28 ± 0.11 L vs. 0.04 ± 0.10 L; p < 0.01). Patients with a progressive pattern of DH presented with higher perception of dyspnea/Tlim rate and lower exercise tolerance than did those with a stable pattern (354 ± 118 s and 465 ± 178 s, respectively; p < 0.05)., Conclusions: The presence of DH is not a universal phenomenon during walking in COPD patients, even in those with moderate to severe airflow limitation. In the patients who presented DH, a progressive pattern of DH had a greater impact on exercise tolerance than did a stable pattern of DH.

Background: It is currently unclear whether the additive effects of a long-acting beta(2)-agonist (LABA) and the antimuscarinic tiotropium bromide (TIO) on resting lung function are translated into lower operating lung volumes and improved exercise tolerance in patients with chronic obstructive pulmonary disease (COPD)., Methods: On a double-blind and cross-over study, 33 patients (FEV(1) = 47.4 +/- 12.9% predicted) were randomly allocated to 2-wk formoterol fumarate 12 microg twice-daily (FOR) plus TIO 18 microg once-daily or FOR plus placebo (PLA). Inspiratory capacity (IC) was obtained on constant-speed treadmill tests to the limit of tolerance (Tlim)., Results: FOR-TIO was superior to FOR-PLA in increasing post-treatment FEV(1) and Tlim (1.34 +/- 0.42 L vs. 1.25 +/- 0.39 L and 124 +/- 27% vs. 68 +/- 14%, respectively; p < 0.05). FOR-TIO slowed the rate of decrement in exercise IC compared to FOR-PLA (Deltaisotime-rest = -0.27 +/- 0.40 L vs. -0.45 +/- 0.36 L, p < 0.05). In addition, end-expiratory lung volume (% total lung capacity) was further reduced with FOR-TIO (p < 0.05). Of note, patients showing greater increases in Tlim with FOR-TIO (16/26, 61.6%) had more severe airways obstruction and lower exercise capacity at baseline. Improvement in Tlim with FOR-TIO was also related to larger increases in FEV(1) (p < 0.05)., Conclusions: Compared to FOR monotherapy, FOR-TIO further improved effort-induced dynamic hyperinflation and exercise endurance in patients with moderate-to-severe COPD. These beneficial consequences were more likely to be found in severely-disabled patients with larger resting functional responses to the combination therapy., Trial Registration: Clinicaltrials.gov Identifier: NCT00680056 [ClinicalTrials.gov].

Inspiratory pressure support (IPS) plus positive end-expiratory pressure (PEEP) ventilation might potentially interfere with the "central" hemodynamic adjustments to exercise in patients with chronic obstructive pulmonary disease (COPD). Twenty-one non- or mildly-hypoxemic males (FEV(1) = 40.1 +/- 10.7% predicted) were randomly assigned to IPS (16 cmH(2)O) + PEEP (5 cmH(2)O) or spontaneous ventilation during constant-work rate (70-80% peak) exercise tests to the limit of tolerance (T (lim)). Heart rate (HR), stroke volume (SV), and cardiac output (CO) were monitored by transthoracic cardioimpedance (Physioflow, Manatec, France). Oxyhemoglobin saturation was assessed by pulse oximetry (SpO(2)). At similar SpO(2), IPS(16) + PEEP(5) was associated with heterogeneous cardiovascular effects compared with the control trial. Therefore, 11 patients (Group A) showed stable or increased Delta "isotime" - rest SV [5 (0-29) mL], lower DeltaHR but similar DeltaCO. On the other hand, DeltaSV [-10 (-15 to -3) mL] and DeltaHR were both lower with IPS(16) + PEEP(5) in Group B (N = 10), thereby reducing DeltaCO (p < 0.05). Group B showed higher resting lung volumes, and T (lim) improved with IPS(16) + PEEP(5) only in Group A [51 (-60 to 486) vs. 115 (-210 to 909) s, respectively; p < 0.05]. We conclude that IPS(16) + PEEP(5) may improve SV and exercise tolerance in selected patients with advanced COPD. Impaired SV and CO responses, associated with a lack of enhancement in exercise capacity, were found in a sub-group of patients who were particularly hyperinflated at rest.

Blood flow requirements of the respiratory muscles (RM) increase markedly during exercise in chronic heart failure (CHF). We reasoned that if the RM could subtract a fraction of the limited cardiac output (QT) from the peripheral muscles, RM unloading would improve locomotor muscle perfusion. Nine patients with CHF (left ventricle ejection fraction = 26 +/- 7%) undertook constant-work rate tests (70-80% peak) receiving proportional assisted ventilation (PAV) or sham ventilation. Relative changes (Delta%) in deoxy-hemoglobyn, oxi-Hb ([O2Hb]), tissue oxygenation index, and total Hb ([HbTOT], an index of local blood volume) in the vastus lateralis were measured by near infrared spectroscopy. In addition, QT was monitored by impedance cardiography and arterial O2 saturation by pulse oximetry (SpO2). There were significant improvements in exercise tolerance (Tlim) with PAV. Blood lactate, leg effort/Tlim and dyspnea/Tlim were lower with PAV compared with sham ventilation (P < 0.05). There were no significant effects of RM unloading on systemic O2 delivery as QT and SpO2 at submaximal exercise and at Tlim did not differ between PAV and sham ventilation (P > 0.05). Unloaded breathing, however, was related to enhanced leg muscle oxygenation and local blood volume compared with sham, i.e., higher Delta[O2Hb]% and Delta[HbTOT]%, respectively (P < 0.05). We conclude that RM unloading had beneficial effects on the oxygenation status and blood volume of the exercising muscles at similar systemic O2 delivery in patients with advanced CHF. These data suggest that blood flow was redistributed from respiratory to locomotor muscles during unloaded breathing.