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Highlights: [•] We compared the cardiorespiratory responses to exercise testing in COPD patients. [•] Physiological responses between treadmill and cycle CPET were similar. [•] Physiological responses were similar between sexes. [•] Either modality can be used when testing mild/moderate COPD patients. [Copyright &y& Elsevier]

Copyright of ConScientiae Saúde is the property of Nove de Julho University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Exercise intolerance is the hallmark of COPD. Static lung hyperinflation and increased dynamic hyperinflation during exercise are associated with reduced functional capacity in COPD patients. Inspiratory capacity correction for the total lung capacity, defined as inspiratory fraction (IF), may be functionally more representative than other traditional indices in these patients. OBJECTIVE: To investigate the association between IF and exercise capacity in patients with stable, moderate to severe COPD. METHODS: Fifty COPD subjects and 34 healthy volunteers constituted the study cohort. Pulmonary function and cardiopulmonary exercise testing were performed, and ventilation and gas exchange parameters were measured. RESULTS: IF was significantly correlated with percent-of-predicted peak oxygen consumption (VO2) in the subjects with COPD (r = 0.52, P < .001). IF was an independent predictor of reduced exercise capacity in the COPD subjects, and was more sensitive and specific than percent-of-predicted FEV1. Statistical analysis generated the equation: percent-of-predicted peak VO2 = 65.9 IF + 0.45 percent-of-predicted FEV1 + 35.8 (RC2 = 0.39, P < .001). The subjects with IF < 0.23 had more severe lung hyperinflation and less exercise capacity than the subjects with IF > 0.23. At peak exercise, the breathing frequencies of the 2 groups were similar, whereas the low-IF subjects had reduced peak minute ventilation and peak tidal volume, relative to the high-IF subjects. CONCLUSIONS: Compared to FEV1, IF is a robust factor to reflect lung hyperinflation and to estimate the exercise capacity of subjects with stable moderate to severe COPD. [ABSTRACT FROM AUTHOR]

Highlights: [•] Diaphragm EMG reached a plateau during either 80% or 60% constant work rate exercise tests. [•] Plateau of the diaphragm EMG during exercise does not mean that there is neural inhibition. [•] Inspiratory capacity maneuver seldom entails a maximal effort even in well trained normal subjects. [ABSTRACT FROM AUTHOR]

Highlights: [•] We assessed the lung function at rest and during exercise in CHF patients. [•] Tidal expiratory flow limitation by NEP was absent during exercise in CHF patients. [•] Forty percent of CHF patients showed dynamic pulmonary hyperinflation (DH) during exercise. [•] CHF patients with effort-induced DH had lower VO2, peak and workload, peak. [•] Worse lung function at rest and DH are associated with less exercise capacity in CHF. [ABSTRACT FROM AUTHOR]

Background: The progression of lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD) has not been studied in a long-term prospective cohort. We explored the longitudinal changes in lung volume compartments with the aim of identifying predictors of a rapid decline of the inspiratory capacity to total lung capacity ratio (IC/TLC). Methods: The study population comprised 324 patients with COPD who were recruited prospectively. Annual rates of changes in pulmonary function, including forced expiratory volume in 1 s (FEV), forced vital capacity (FVC), total lung capacity (TLC), functional residual capacity (FRC), residual volume (RV), vital capacity (VC), IC, and IC/TLC, were estimated using the random coefficient models. Results: The mean annual rates of changes in pre- and post-bronchodilator FEV were −23.0 mL/year ( p < 0.001) and −26.5 mL/year ( p = 0.004). The mean annual rates of changes in VC, IC, TLC, and IC/TLC were −33.7 mL/year ( p = 0.007), −53.9 mL/year ( p < 0.001), −43.7 mL/year ( p = 0.012), and −0.65 %/year ( p = 0.001), respectively. RV, FRC, and RV/TLC did not change significantly during the study period. Multivariate logistic regression analysis showed that a high modified Medical Research Council (MMRC) dyspnea scale score, a high Charlson comorbidity index value, and low post-bronchodilator FEV were associated with rapid decline in IC/TLC. Conclusion: MMRC dyspnea scale, post-bronchodilator FEV and the Charlson comorbidity index at baseline were independent predictors of a rapid decline in IC/TLC. [ABSTRACT FROM AUTHOR]

Background: Exercise intolerance is a hallmark of chronic obstructive pulmonary disease (COPD) and forced expiratory volume in one second (FEV1) is the traditional metric used to define the severity of COPD. However, there is dissociation between FEV1 and exercise capacity in a large proportion of subjects with COPD. The aim of this study was to investigate whether other lung function parameters have an additive, predictive value for exercise capacity and whether this differs according to the COPD stage. Methods: Spirometry, body plethysmography and diffusing capacity for carbon monoxide (DLCO) were performed on 88 patients with COPD GOLD stages II-IV. Exercise capacity (EC) was determined in all subjects by symptom-limited, incremental cycle ergometer testing. Results: Significant relationships were found between EC and the majority of lung function parameters. DLCO, FEV1 and inspiratory capacity (IC) were found to be the best predictors of EC in a stepwise regression analysis explaining 72% of EC. These lung function parameters explained 76% of EC in GOLD II, 72% in GOLD III and 40% in GOLD IV. DLCO alone was the best predictor of exercise capacity in all GOLD stages. Conclusions: Diffusing capacity was the strongest predictor of exercise capacity in all subjects. In addition to FEV1, DLCO and IC provided a significantly higher predictive value regarding exercise capacity in COPD patients. This suggests that it is beneficial to add measurements of diffusing capacity and inspiratory capacity when clinically monitoring COPD patients. [ABSTRACT FROM AUTHOR]

Patients with chronic obstructive pulmonary disease (COPD) are progressively limited in their ability to undertake normal everyday activities by a combination of exertional dyspnoea and peripheral muscle weakness. COPD is characterised by expiratory flow limitation, resulting in air trapping and lung hyperinflation. Hyperinflation increases acutely under conditions such as exercise or exacerbations, with an accompanying sharp increase in the intensity of dyspnoea to distressing and intolerable levels. Air trapping, causing increased lung hyperinflation, can be present even in milder COPD during everyday activities. The resulting activity-related dyspnoea leads to a vicious spiral of activity avoidance, physical deconditioning, and reduced quality of life, and has implications for the early development of co- morbidities such as cardiovascular disease. Various strategies exist to reduce hyperinflation, notably long-acting bronchodilator treatment (via reduction in flow limitation and improved lung emptying) and an exercise programme (via decreased respiratory rate, reducing ventilatory demand), or their combination. Optimal bronchodilation can reduce exertional dyspnoea and increase a patient's ability to exercise, and improves the chance of successful outcome of a pulmonary rehabilitation programme. There should be a lower threshold for initiating treatments appropriate to the stage of the disease, such as long-acting bronchodilators and an exercise programme for patients with mild-to-moderate disease who experience persistent dyspnoea. [ABSTRACT FROM AUTHOR]

Background and Aim: Dynamic hyperinflation (DH) is a major contributor to exercise intolerance in patients with obstructive lung diseases. However, it has not been investigated in children with bronchiectasis (BE). We aimed to investigate dynamic ventilatory responses and their influence on functional exercise capacity in children with BE., Methods: Forty children with BE (mean forced expiratory volume in 1 s [FEV 1 ] = 78 ± 19%pred) were included. Six-minute walk test (6MWT) was conducted using Spiropalm 6MWT® for evaluating dynamic ventilatory responses including inspiratory capacity (IC), minute ventilation (VE), breathing reserve (BR) and respiratory rate (RR). A decrease of ≥100 ml in IC during exertion was defined as DH. Also, spirometry was performed, and peripheral muscle strength were measured., Results: Twenty patients (50%) developed DH, and four patients (10%) were ventilatory limited (BR < %30) during 6MWT. There was a 176 [100-590] ml decrease in IC after exertion in patients with DH. DH did not correlate to clinical or functional indicators of the disease, except for an increase in RR (∆RR) during exertion. High ∆RR was associated with presence of DH (r pb = 0.390; p < 0.05). Clinical features, peripheral muscle strength, and Spiropalm 6MWT metrics including 6MWT distance did not differ between patients with and without DH. Univariate analysis revealed FVC% (R = 0.340), VE peak (R = 0.565), quadriceps strength (R = 0.698) and handgrip strength (R = 0.711) were the only predictors of 6MWT distance (p < 0.05)., Conclusion: Although DH is common in children with BE, the severity of DH is rather low and may not seem to affect functional exercise capacity. However, peripheral muscle strength was a major contributor to functional exercise capacity., (© 2022 Wiley Periodicals LLC.)

Introduction This prospective study was carried out to investigate if metronome-paced tachypnea ( MPT) can serve as an accurate diagnostic tool to identify patients with chronic obstructive pulmonary disease ( COPD) who are susceptible to develop dynamic hyperinflation during exercise. Commonly, this is assessed by measuring change in inspiratory capacity ( IC) during cardiopulmonary exercise testing ( CPET), which, however, is complex and laborious. Methods Fifty-three patients with COPD ( FEV1 58 ± 22%pred) and 20 age-matched healthy subjects were characterized by lung function testing and performed CPET (reference standard) and MPT. The repeatability coefficient of IC (10·2%) was used as cut-off to classify subjects as hyperinflators during CPET. Subsequently, dynamic hyperinflation was measured after MPT. With receiver operating characteristic analysis, the optimal cut-off for MPT-induced dynamic hyperinflation was determined and sensitivity and specificity of MPT to identify hyperinflators were evaluated. Results With 10·2% decrease in IC as cut-off for CPET-induced dynamic hyperinflation, the optimal cut-off for MPT was 11·1% decrease in IC. Using these cut-offs, MPT had a sensitivity of 85% and specificity of 85% to identify the subjects who hyperinflated during CPET. Conclusions The MPT test shows good overall accuracy to identify subjects who are susceptible to develop dynamic hyperinflation during CPET. Before considering the use of MPT as a screening tool for dynamic hyperinflation in COPD, sensitivity and specificity need further evaluation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Expiratory positive airway pressure (EPAP) is a form of noninvasive positive-pressure ventilatory support that, in spite of not unloading respiratory muscles during inspiration, may reduce the inspiratory threshold load and attenuate expiratory dynamic airway compression, contributing to reduced expiratory air-flow limitation in patients with COPD. We sought to determine the effects of EPAP on operational lung volumes during exercise in COPD patients. METHODS: This was a nonrandomized, experimental comparison of 2 exercise conditions (with and without EPAP); subjects completed a treadmill exercise test and performed, before and immediately after exercise, lung volume measurements. Those who overtly developed dynamic hyperinflation (DH), as defined by at least a 15% reduction from pre-exercise inspiratory capacity (IC), were invited for an additional research visit to repeat the same exercise protocol while receiving EPAP through a spring loaded resistor face mask. The primary outcome was IC variance (pre-post exercise) comparison under the 2 exercise conditions. RESULTS: Forty-six subjects (32 males), a mean 65.0 ± 8.2 years of age, and with moderate to severe COPD (FEV1 = 38 ± 16% predicted) were initially enrolled. From this initial sample, 17 (37%) presented overt DH, as previously defined. No significant difference was found between these subjects and the rest of the initial sample. Comparing before and after exercise, there was significantly less reduction in IC observed when EPAP was used (-0.18 ± 0.35 L vs -0.57 ± 0.45 L, P = .02), allowing greater IC final values (1.45 ± 0.50 L vs 1.13 ± 0.52 L, P = .02). CONCLUSIONS: The application of EPAP reduced DH, as shown by lower operational lung volumes after submaximal exercise in COPD patients who previously manifested exercise DH. [ABSTRACT FROM AUTHOR]

Background: The changes in inspiratory capacity (IC) over time in chronic obstructive pulmonary disease (COPD) patients are unknown. The Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFTW®) trial included IC measurements. Methods: IC analysis from UPLIFTW® (N = 5992) was performed at 1 and 6 months, and every 6 months through 4 years. Annualized rate of decline in pre- and post-bronchodilator IC and mean differences at each time point were analyzed by mixed-effects models. The relationships between baseline IC and exacerbation rate and mortality were explored using Cox regression analysis. Results: Baseline characteristics: age, 65 years; 75% men; post-bronchodilator forced expiratory volume in 1 second, 1.32 L (48% predicted); pre- and post-bronchodilator IC, 2.03 and 2.33 L. Mean IC rate of decline (mL/year) was 34 ± 2 (1.7% of baseline) and 50 ± 3 (2.1% of baseline) pre- and post-bronchodilator, respectively, without significant between-group differences. Morning pre-bronchodilator (trough) IC improved with tiotropium versus placebo: 124 mL (1 month), 103 mL (1 year), 107 mL (2 years), 98 mL (3 years), and 97 mL (4 years) (all p < 0.001). Postbronchodilator improvements were similar between treatment groups. Lower baseline IC values were associated with reduced time to first exacerbation. For the lowest quartile (n = 1413) the values in months were 14.3 (11.7- 17.0) for tiotropium and 10.3 (8.8-11.7) for controls (p < 0.01). Conclusion: IC declines from approximately 34 to 50 mL/year in patients with stage II to IV COPD. Tiotropium treatment does not change the IC decline rate but provides 24-hour improvements in IC sustained over the long term. Trough IC differences suggest that tiotropium provides sustained decrease in end-expiratory lung volume. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Pulmonology / Jornal Brasileiro de Pneumologia is the property of Sociedade Brasileira de Pneumologia e Tisiologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Indacaterol is a novel, inhaled once-daily ultra long-acting β2-agonist for the treatment of COPD. This randomised, double-blind, placebo-controlled, two-period crossover study evaluated the effect of two-week treatment with indacaterol 300 μg on peak and isotime exercise inspiratory capacity (IC) in patients with COPD. Patients (40-80 years) with post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <70%%, percent predicted FEV1 ≥40%% and ≤80%%, smoking history ≥20 pack-years and functional residual capacity >120%% of predicted normal were randomised to receive indacaterol 300 μg or placebo once-daily via a single-dose dry powder inhaler. Following 14 days of treatment, IC at peak and isotime during constant-load (80%% of maximum workload) cycle ergometry was analysed using linear mixed-effects models. Safety and tolerability were also monitored. Twenty-seven patients (67%% male; mean age, 61.3 years) were randomised; 24 completed the study. On Day 14, indacaterol showed statistically significant improvements over placebo in peak (317 mL [[95%% CI: 118-517]]; p < 0.01) and isotime IC (268 mL [[95%% CI: 104-432]]; p < 0.01). Statistically significant improvements were observed with indacaterol versus placebo on Day 14 for the following secondary endpoints: resting IC, trough FEV1, dyspnoea (BDI/TDI and Borg CR10 scale at isotime) and exercise endurance time. Indacaterol was well tolerated, with no serious adverse events or deaths. In conclusion, indacaterol 300 μg administered once-daily showed a clinically relevant increase in IC after 14 days of treatment, reflecting a reduction in dynamic hyperinflation. [ABSTRACT FROM AUTHOR]

Background and Objectives: It is increasingly recognized that a low grade of systemic inflammation occurs in patients with advanced chronic obstructive pulmonary disease (COPD). C-reactive protein (CRP), a marker of systemic chronic inflammatory response, has been related with decreased survival in large cohorts of COPD patients. The aim of the study was to assess if resting dynamic pulmonary hyperinflation (DH) is linked to the presence of systemic inflammation in COPD. Materials and Methods: In a 12-month retrospective study involving 55 out-patients with COPD (FEV1 59±23% pred.) examined in stable conditions, inspiratory capacity (IC) was measured at rest and considered as index of DH when lower than 80% predicted. Simultaneously, CRP (by immuno-turbidometry) and white blood cells (WBC), uric acid and alpha-1 globulins were measured in the venous blood in the morning before eating. Results: CRP was significantly increased in the COPD patients with IC <80% pred. (n=35; IC= 61+14% pred.) as compared with that measured in COPD patients with IC >80% pred. (n=20; IC = 97+13% pred.), amounting to 0.70±0.59 vs 0.29±0.28 mg/dl, respectively (p<0.01). CRP was inversely related to IC (% pred.) (r=0.45, p<0.01). WBC, serum uric acid (an endogenous danger signal), and albumin and alfa-1 globulins were not different between the two groups. Discussion: These results show that the IC reduction is associated with higher serum levels of CRP in stable COPD patients, suggesting a potential role of dynamic pulmonary hyperinflation on development and maintenance of low grade systemic inflammation in COPD. [ABSTRACT FROM AUTHOR]

Background: Over the past decade inspiratory capacity (IC) has received increasing attention, especially in studies on chronic obstructive pulmonary disease. Though a few recent studies provide reference values for IC, still little is known on the distribution of its values in healthy subjects. Objective: To estimate percentiles of IC in a sample of healthy nonsmokers by applying quantile regression. Methods: We applied quantile regression to estimate seven percentiles of IC from 5 to 95% for a given age, height and body mass index, separately in males and females, in a sample of 411 healthy nonsmokers, aged 8-73 years, drawn from the general population in Northern Italy. Results: The magnitude and statistical significance of the effect of age, height and body mass on IC varied across percentiles and between genders. When the 50th percentile of IC was compared with the predicted values of several studies, including those published by the European Community for Coal and Steel, the differences were as large as 0.86 liters in males and 0.90 liters in females. The possible advantage of the 5th percentile predicted from quantile regression over the 'traditional 5th percentile' as lower limit of normal was also illustrated. Conclusions: Inference on percentiles, rather than just the mean, of IC and other lung function measures may help in the future to better understand the effect of various risk factors, model growth curves and derive more accurate reference values. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Summary: Background: Indacaterol is a novel, inhaled, once-daily ultra long-acting β2-agonist (ultra-LABA) for the treatment of COPD. This study investigated the effect of indacaterol on exercise endurance, and on lung hyperinflation during exercise and at rest in patients with moderate-to-severe COPD. Methods: In this double-blind, placebo-controlled, two-period crossover study (3-week treatment, 3-week washout between treatments), patients were randomized to receive indacaterol 300 μg once-daily or matching placebo. The primary efficacy variable was exercise endurance time after 3 weeks of treatment, measured through constant-load cycle ergometry testing performed at 75% of the peak work rate in a screening incremental exercise test. Results: Of 90 patients randomized (mean age: 62.8 years; post-bronchodilator FEV1: 61.2% predicted and FEV1/FVC: 51.6%), 74 completed the study. Pre-treatment exercise tolerance averaged 459 s. Improvement in exercise endurance time was higher with indacaterol 300 μg than with placebo both after the first dose (treatment difference: 101 s; p < 0.001) and after 3 weeks (treatment difference: 111 s; p = 0.011). In addition, indacaterol increased end-exercise inspiratory capacity (IC) versus placebo after 3 weeks (0.28 L, p = 0.002). Significant improvements were also observed in resting IC (0.17 L, p = 0.001), FEV1 (0.25 L, p < 0.001) and FVC (0.26 L, p < 0.001) with indacaterol compared with placebo at 75 min post-dose after 3 weeks. Conclusion: In conclusion, indacaterol treatment improved the ability of patients with COPD to exercise. In addition, the improvements observed in resting and end-exercise IC indicate reductions in lung hyperinflation after 3 weeks treatment (ClinicalTrials.gov registration number: NCT00620022). [ABSTRACT FROM AUTHOR]

The article presents a study which examines the breathing pattern's effect on dynamic hyperinflation (DH) of patients with chronic obstructive pulmonary disease (COPD) and compare DH at similar ventilation during leg and arm exercises. It states that an arm and leg constant work rate (CWR) ergometry were performed on 13 participants with mild to severe COPD. It adds that the respiratory physiology of the patients was measured breath-by-breath. Results show that there is a similar degree of DH in the participants during the leg and arm CWR tests. It adds that the level of DH was not affected by the differences in the observed breathing frequency during the exercises.

Abstract: Purpose: Indacaterol is a novel, once daily, inhaled ultra-long-acting β2-agonist for the treatment of chronic obstructive pulmonary disease (COPD). Here we compared the 24-h spirometry profile of once daily indacaterol 300 μg with that of placebo and twice daily salmeterol 50 μg in patients with COPD. Methods: This randomized, multicenter, placebo-controlled, crossover study comprised three 14-day treatment periods (with 14-day washouts). Patients (male/female ≥40 years) with moderate-to-severe COPD were randomized to receive double-blind indacaterol 300 μg or placebo once daily, or open-label salmeterol 50 μg twice daily. The primary outcome measure was 24-h post-dose (trough) FEV1 (mean of FEV1 at 23 h 10 min and 23 h 45 min post-indacaterol dose) after 14 days. FEV1 was assessed at multiple time points on Days 1 and 14 of each treatment period. Safety and tolerability were also monitored. Results: Of 68 randomized patients, 61 completed. Trough FEV1 (primary endpoint) on Day 14 for indacaterol was 200 mL higher than placebo (p < 0.001), exceeding the prespecified minimum clinically important difference (120 mL), and was 90 mL higher than for salmeterol (p = 0.011). After Day 1, trough FEV1 for indacaterol was 150 mL higher than placebo (p < 0.001). Indacaterol provided superior bronchodilation compared with placebo (p < 0.001) across the full 24-h assessment period on Days 1 and 14. In addition, on both days, indacaterol provided superior FEV1 compared with salmeterol (p < 0.05) at many post-baseline time points, including 5 min post-dose. All treatments were well tolerated. Conclusions: Once daily indacaterol 300 μg produced effective sustained 24-h bronchodilation from the first dose, an efficacy profile superior to placebo and twice daily salmeterol. Given its effective bronchodilation with once daily dosing, indacaterol is likely to be a useful treatment option for patients with moderate-to-severe COPD. [Copyright &y& Elsevier]

Summary: Background: The predictive factors for treatment response in patients with severe chronic obstructive pulmonary disease (COPD) are unknown. We investigated predictive factors for response to fluticasone propionate/salmeterol (FSC) in severe COPD patients. Methods: This prospective, open-label, non-comparative study included 921 adult patients with severe COPD (baseline forced expiratory volume in 1 s (FEV1) <50% of predicted), a history of repeated exacerbations, and symptoms despite bronchodilator treatment. FSC (500 μg/50 μg) was delivered via an inhaler, twice a day, for 12 weeks. The primary efficacy endpoint was the response rate for inspiratory capacity (IC), FEV1, or quality of life (QoL), assessed with the Saint George’s respiratory questionnaire, at week 6 and week 12. Results: The overall response rate to FSC at 6 and 12 weeks was 79%. The corresponding rates for FEV1, IC, and QoL were 38%, 55%, and 62%, respectively. More than 40% of patients showed a response for IC and/or QoL without being responders for FEV1. Overall lung function and QoL were improved. FSC was well tolerated with a safety profile consistent with that observed previously. Conclusion: Nearly 80% of patients responded to FSC treatment in this real-life study. Improvements in IC and QoL at 12 weeks revealed a clinically relevant response in patients with no improvement in FEV1. IC reversibility to salbutamol before treatment might represent, better than FEV1, a prognostic factor of response to FSC in severe COPD. Moreover these tests are easy to perform routinely and in large numbers of patients. [ABSTRACT FROM AUTHOR]

Abstract: With the rapid somatic growth and development in infants, simultaneous accurate measurements of lung volume and airway function are essential. Raised volume rapid thoracoabdominal compression (RTC) is widely used to generate forced expiration from an airway opening pressure of 30cmH2O (V 30). The (dynamic) functional residual capacity (FRCdyn) remains the lung volume most routinely measured. The aim of this study was to develop comprehensive integrated spirometry that included all subdivisions of lung volume at V 30 or total lung capacity (TLC30). Measurements were performed on 17 healthy infants aged 8.6–119.7 weeks. A commercial system for multiple-breath nitrogen washout (MBNW) to measure lung volumes and a custom made system to perform RTC were used in unison. A refined automated raised volume RTC and the following two novel single maneuvers with dual volume measurements were performed from V 30 during a brief post-hyperventilation apneic pause: (1) the passive expiratory flow was integrated to produce the inspiratory capacity (IC) and the static (passive) FRC (FRCst) was estimated by initiating MBNW after end-passive expiration; (2) RTC was initiated late during passive expiration, flow was integrated to produce the slow vital capacity ( j SVC) and the residual volume (RV) was measured by initiating MBNW after end-expiration while the jacket (j) was inflated. Intrasubject FRCdyn and FRCst measurements overlapped (p =0.6420) but neither did with the RV (p <0.0001). Means (95% confidence interval) of FRCdyn, IC, FRCst, j SVC, RV, forced vital capacity and tidal volume were 21.2 (19.7–22.7), 36.7 (33.0–40.4), 21.2 (19.6–22.8), 40.7 (37.2–44.2), 18.1 (16.6–19.7), 40.7 (37.1–44.2) and 10.2 (9.6–10.7)ml/kg, respectively. Static lung volumes and capacities at V 30 and variables from the best forced expiratory flow-volume curve were dependent on age, body length and weight. In conclusion, we developed a comprehensive physiologically integrated approach for in-depth investigation of lung function at V 30 in infants. [Copyright &y& Elsevier]

Abstract: Background: Resting inspiratory capacity (IC) reflects static hyperinflation in chronic obstructive pulmonary disease (COPD). This study compared the effects of formoterol and indacaterol, a novel once-daily ultra-long-acting β2-agonist (or ultra-LABA), on resting IC and forced expiratory volume in 1s (FEV1). Methods: Thirty patients with COPD (mean FEV1/FVC 0.49, mean FEV1 56% predicted) each inhaled three treatments (two in randomized sequence followed by open-label formoterol) on separate study days: a single dose of indacaterol 300μg, matching placebo, and two doses of formoterol 12μg 12h apart. Results: Indacaterol and formoterol increased FEV1 and IC at all time points relative to placebo (p <0.001). Peak effects on FEV1 were similar, while indacaterol had a greater effect on peak IC (31% vs 23% from pre-dose; p =0.034). Indacaterol had a greater effect than formoterol on FEV1 at 8h (1.47 vs 1.39L; p =0.014) and 24h (1.44 vs 1.35L; p =0.003), and on IC from 4 to 24h (differences of 0.13–0.19L; p <0.05). At 24h, indacaterol and formoterol increased FEV1 by 17.7% and 7.5%, respectively, from pre-dose. Conclusions: This study discriminated between the effects on IC and FEV1 of once daily indacaterol and twice daily formoterol. The greater effect of indacaterol on IC may translate into improved long-term clinical outcomes. [Copyright &y& Elsevier]

Clinically, the symptoms and limited exercise capabilities of patients with chronic obstructive pulmonary disease (COPD) correlate better with changes in lung volumes than with airflow measurements. The realization of the clinical importance of hyperinflation has been overshadowed for decades by the use of forced expiratory volume during 1 s (FEV1) and the ratio of the FEV1 to the forced expiratory vital capacity (FEV1/FVC) to categorize the severity and progression of COPD. Hyperinflation is defined as an elevation in the end-expiratory lung volume or functional residual capacity. When severe hyperinflation encroaches upon inspiratory capacity and limits vital capacity, it results in elevated intrinsic positive end-expiratory pressure (PEEPi) that places the diaphragm at a mechanical disadvantage and increases the work of breathing. Severe hyperinflation is the major physiologic cause of the resulting hypercarbic respiratory failure and patients’ inability to transition (i.e. wean) from mechanical ventilatory support to spontaneous breathing. This paper reviews the basic physiologic principles of hyperinflation and its clinical manifestations as demonstrated by PEEPi. Also reviewed are the adverse effects of hyperinflation and PEEPi in critically ill patients with COPD, and methods for minimizing or counterbalancing these effects. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira em Promoção da Saúde is the property of Revista Brasileira em Promocao da Saude and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In COPD patients, tachypnea should increase (dynamic) hyperinflation by shortening expiratory time. We developed a method to evaluate the time course and degree of dynamic hyperinflation during metronome-paced tachypnea. Fourteen patients with stable COPD (FEV1 43 ± 13% predicted) were studied. Inspiratory capacity (IC) was measured breathing through a flow transducer. Subjects paced their respiratory rate (fR) at 20/min, 30/min and 40/min for 60-second periods in response to audible tones generated by a computer. IC measurements were obtained at baseline and after 30 and 60 seconds at each fR. End-tidal carbon dioxide was monitored and fR was allowed to return to baseline between periods of tachypnea. Tachypnea produced reductions in IC of 200 ± 240 ml, 380 ± 330 ml and 540 ± 300 ml after 30 seconds at 20/min, 30/min and 40/min, respectively. IC reduction at 60 seconds was similar to 30 seconds for each fR. In patients with moderate-to-severe COPD, the dynamic hyperinflation induced by metronome-paced tachypnea was shown to occur rapidly and be complete by 30 seconds for a given fR. Controlled increments in fR produced stepwise increases in dynamic hyperinflation. This standardized method could be a useful and easier method of assessing dynamic hyperinflation in COPD patients before and after therapeutic interventions. [ABSTRACT FROM AUTHOR]

The prevalence of activity-related breathlessness increases with age, particularly in women, but the specific underlying mechanisms have not been studied. This novel cross-sectional study was undertaken to examine the effects of age and sex, and their interaction, on the perceptual and ventilatory responses to incremental treadmill exercise in 73 healthy participants (age range 40-80 yr old) with normal pulmonary function: Age-related changes at a standardized oxygen uptake (Vo2) during exercise included significant increases in breathlessness ratings (Borg scale), ventilation (VE), ventilatory equivalent for carbon dioxide, and the ratio of tidal volume (VT) to dynamic inspiratory capacity (IC) (all P < 0.05). These changes were quantitatively similar in women (n = 39) and in men (n = 34). For the group as a whole, exertional breathlessness ratings increased as resting static inspiratory muscle strength diminished (P = 0.05), as exercise ventilation increased relative to capacity (P = 0.0 13) and as the VT/IC ratio increased (P = 0.003) during exercise. Older women (60-80 yr old, n = 23) reported greater (P < 0.05) intensity of exertional breathlessness at a standardized Vo2 and VE than age-matched men (n = 16), despite similar age-related changes in ventilatory demand and dynamic ventilatory mechanics. These increases in breathlessness ratings in older women disappeared when sex differences in baseline maximal ventilatory capacity were accounted for. In conclusion, although increased exertional breathlessness with advancing age is multifactorial, contributory factors included higher ventilatory requirements during exercise, progressive inspiratory muscle weakness, and restrictive mechanical constraints on VT expansion related to reduced IC. The sensory consequences of this age-related respiratory impairment were more pronounced in women, who, by nature, have relatively reduced maximal ventilatory reserve. [ABSTRACT FROM AUTHOR]

Background and objective: Thixotropy conditioning of inspiratory muscles changes the end-expiratory position of the respiratory system during resting breathing. We examined the immediate effects of thixotropy conditioning of inspiratory muscles on chest wall inflation induced by CPAP. Methods: A cross-over design study was performed in 13 healthy men. Operating chest wall volume (Vcw) was measured by respiratory inductive plethysmography. Conditioning consisting of a 5 s inspiratory effort at a mask pressure of −20 cm H2O was performed under CPAP (10 cm H2O) at three Vcw values to change the muscle length at which conditioning occurred: (i) FRC at a CPAP of 10 cm H2O (FRC10); (ii) FRC at a CPAP of 0 cm H2O (FRC0); and (iii) RV at a CPAP of 10 cm H2O (RV10). Results: CPAP (10 cm H2O) increased FRC by 0.60–0.70 L. Decreases in operating Vcw were noted after conditioning at RV10, which decreased end-expiratory Vcw by 0.16 ± 0.12 L and end-inspiratory Vcw by 0.20 ± 0.14 L at 180 s ( P < 0.01). Inspiratory capacity (1.59 ± 0.45 L) and inspiratory reserve volume (1.18 ± 0.40 L) were greater than preconditioning values (1.44 ± 0.49 L and 0.99 ± 0.41 L, respectively; P < 0.01). Conditioning at FRC0 also decreased operating Vcw significantly, but conditioning at FRC10 did not change operating Vcw. Conclusions: Thixotropy conditioning of inspiratory muscles performed below inflated FRC decreased the level of CPAP-induced inflation. [ABSTRACT FROM AUTHOR]

Background and objective: Hyperinflation with a decrease in inspiratory capacity (IC) is a common presentation for both unstable and stable COPD patients. As CPAP can reduce inspiratory load, possibly secondary to a reduction in hyperinflation, this study examined whether CPAP would increase IC in stable COPD patients. Methods: Twenty-one stable COPD patients (nine emphysema, 12 chronic bronchitis) received a trial of CPAP for 5 min at 4, 7 and 11 cmH2O. Fast and slow VC (SVC) were measured before and after each CPAP trial. In patients in whom all three CPAP levels resulted in a decreased IC, an additional trial of CPAP at 2 cmH2O was conducted. For each patient, a ‘best CPAP’ level was defined as the one associated with the greatest IC. This pressure was then applied for an additional 10 min followed by spirometry. Results: Following application of the ‘best CPAP’, the IC and SVC increased in 15 patients (nine emphysema, six chronic bronchitis). The mean change in IC was 159 mL (95% CI: 80–237 mL) and the mean change in SVC was 240 mL (95% CI: 97–386 mL). Among these patients, those with emphysema demonstrated a mean increase in IC of 216 mL (95% CI: 94–337 mL). Six patients (all with chronic bronchitis) did not demonstrate any improvement in IC. Conclusions: The best individualized CPAP can increase inspiratory capacity in patients with stable COPD, especially in those with emphysema. [ABSTRACT FROM AUTHOR]