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Background: Mosaicism and hyperinflation are common pathophysiologic features of bronchiectasis. The magnitude of ventilation heterogeneity might have been affected by the degree of hyperinflation. Some studies have evaluated the discriminative performance of lung clearance index (LCI) in bronchiectasis patients, but the additive diagnostic value of hyperinflation metrics to LCI is unknown., Objective: To compare LCI and the ratio of residual volume to total lung capacity (RV/TLC), along with the LCI normalized with RV/TLC, in terms of discriminative performance, correlation and concordance with clinical variables in adults with bronchiectasis., Methods: Measurement items included chest high-resolution computed tomography, multiple-breath nitrogen washout test, spirometry, and sputum culture. We analyzed bronchodilator responses by stratifying LCI and RV/TLC according to their median levels (LCIHigh/RV/TLCHigh, LCILow/RV/TLCHigh, LCIHigh/RV/TLCLow, and LCILow/RV/TLCLow)., Results: Data from 127 adults with clinically stable bronchiectasis were analyzed. LCI had greater diagnostic value than RV/TLC in discriminating moderate-to-severe from mild bronchiectasis, had greater concordance in reflecting clinical characteristics (including the number of bronchiectatic lobes, radiological severity score, and the presence of cystic bronchiectasis). Normalization of LCI with RV/TLC did not contribute to greater discriminative performance or concordance with clinical variables. The LCI, before and after normalization with RV/TLC, correlated statistically with age, sex, HRCT score, Pseudomonas aeruginosa colonization, cystic bronchiectasis, and ventilation heterogeneity (all P<0.05). Different bronchodilator responses were not significant among the four subgroups of bronchiectasis patients, including those with discordant LCI and RV/TLC levels., Conclusion: LCI is superior to RV/TLC for bronchiectasis assessment. Normalization with RV/TLC is not required. Stratification of LCI and RV/TLC is not associated with significantly different bronchodilator responses.

Background: Cycle ergometer training (CET) has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT) may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment., Materials and Methods: Eighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group), 27 received 8 weeks of CET alone (CET group), and 26 only received 8 weeks of free walking (control group). Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program., Results: Respiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group ( P <0.05) after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPI max [maximal inspiratory pressure] 5.20±0.89 cmH 2 O vs 1.32±0.91 cmH 2 O; P <0.05). However, there were no significant differences in the other indices between the two groups ( P >0.05). Patients with weakened respiratory muscles in the combined training group derived no greater benefit than those without respiratory muscle weakness ( P >0.05). There were no significant differences in these indices between the patients with malnutrition and normal nutrition after pulmonary rehabilitation program ( P >0.05)., Conclusion: Combined training is more effective than CET alone for increasing inspiratory muscle strength. IMT may not be useful when combined with CET in patients with weakened inspiratory muscles. Nutritional status had slight impact on the effects of pulmonary rehabilitation. A comprehensive assessment approach can be more objective to evaluate the effects of combined CET and IMT., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Noninvasive ventilation with a plateau exhalation valve (PEV) is often used as an adjunct to exercise to achieve a physiologic training effect in severe chronic obstructive pulmonary disease (COPD) patients. However, during exercise, with the increase of exhalation flow and respiratory rate and limited capability of PEV to exhale gases out of the circuit, it is still unknown whether CO 2 rebreathing occurs in COPD patients ventilated during exercise assisted by single-limb circuit with a PEV. A maximal symptom-limited cycle exercise test was performed while ventilated on pressure support (inspiratory:expiratory pressure 14:4 cmH 2 O) in 18 male patients with stable severe COPD (mean ± standard deviation, forced expiratory volume in 1 s: 29.5%±6.9% predicted). At rest and during exercise, breathing pattern, mean expiratory flow, mean expiratory flow of PEV, and the mean inspiratory fraction of CO 2 (tidal fractional concentration of inspired CO 2 [FiCO 2 ]) reinsufflated from the circuit was measured for each breath. In comparison with rest, with the significant increase of mean expiratory flow (0.39±0.15 vs 0.82±0.27 L/s), fractional concentration of end-tidal CO 2 (2.6%±0.7% vs 5.5%±0.6%), and the significant decrease of mean expiratory flow of PEV (0.41±0.02 vs 0.39±0.03 L/s), tidal FiCO 2 significantly increased at peak exercise (0.48%±0.19% vs 1.8%±0.6%) in patients with stable severe COPD. The inflection point of obvious CO 2 rebreathing was 0.67±0.09 L/s (95% confidence interval 0.60-0.73 L/s). Ventilated by a single-limb tubing with PEV caused CO 2 rebreathing to COPD patients during exercise. Patients with mean expiratory flow >0.60-0.73 L/s may be predisposed to a higher risk of CO 2 rebreathing., Competing Interests: The authors report no conflicts of interest in this work.

Background: It is difficult to differentiate between chronic obstructive pulmonary disease (COPD) and asthma in clinics; therefore, for diagnostic purposes, imaging-based measurements could be beneficial to differentiate between the two diseases., Objectives: We aim to analyze quantitative measurements of the lung and bronchial parameters that are provided by low-dose computed tomography (CT) to differentiate COPD and asthma from an imaging perspective., Materials and Methods: 69 COPD patients, 52 asthma patients, and 20 healthy subjects were recruited to participate in CT imaging and pulmonary function tests (PFTs). Comparative analysis was performed to identify differences between COPD and asthma in CT measurements. PFT measurements enabled validation of the differentiation between COPD and asthma patients., Results: There were significant differences among the COPD, asthma, and healthy control groups. The differences were more significant among the following: inspiratory emphysema index (EI)-950 (%), expiratory lung volume, expiratory mean lung density (MLD), and expiratory EI-950 (%) and EI-850 (%). The COPD group had a significantly higher EI-950 (%) than the asthma group (p = 0.008). There were significant differences among the three groups in lumen area (LA), wall area (WA), total area, and Pi10WA. The asthma group had significantly higher WA%/WV% than both the COPD (p = 0.002) and the control group (p = 0.012). There was high sensitivity in EI-950 (%), EI-850 (%) and expiratory MLD in the parenchyma and high sensitivity in LA and Pi10WA in small airways in the differential diagnosis of COPD and asthma., Conclusion: To aid the diagnosis, CT can provide quantitative measurements to differentiate between COPD and asthma patients., (© 2017 S. Karger AG, Basel.)

Purpose: Patients with COPD often experience skeletal muscle dysfunction. For those who are unable or unwilling to undertake physical training, neuromuscular electrical stimulation (NMES) may provide an alternative method of rehabilitation. The purpose of this meta-analysis was to investigate the controversial topic of whether this therapy is effective in patients with moderate-to-severe COPD., Patients and Methods: We pooled data from nine trials published between January 9, 2002 and January 4, 2016 across PubMed, Embase, Cochrane Central Register of Controlled Trials, Google Scholar, and relevant websites for randomized controlled trials. In these trials, patients with moderate-to-severe COPD were randomly allocated to receive NMES. Primary outcomes were quadricep strength and exercise capacity. The secondary outcome was health-related quality of life., Results: We extracted data from 276 patients. NMES contributed to statistically improved quadricep strength (standardized mean difference 1.12, 95% confidence interval [CI] 0.64-1.59, I 2 =54%; P <0.00001) and exercise capacity, including longer exercise distance (weighted mean difference 51.53, 95% CI 20.13-82.93, I 2 =90%; P =0.001), and longer exercise endurance (standardized mean difference 1.11, 95% CI 0.14-2.08, I 2 =85%; P =0.02). There was no significant difference in St George's Respiratory Questionnaire scores (weighted mean difference -0.07, 95% CI -2.44 to 2.30, I 2 =56%; P =0.95)., Conclusion: NMES appears an effectual means of enhancing quadricep strength and exercise capacity in moderate-to-severe COPD patients. Further research is demanded to clarify its effect on other outcomes and determine the optimal parameters for an NMES program., Competing Interests: The authors report no conflicts of interest in this work.

Little is known about the comparative diagnostic value of lung clearance index (LCI) and maximal mid-expiratory flow (MMEF) in bronchiectasis. We compared the diagnostic performance, correlation and concordance with clinical variables, and changes of LCI and MMEF% predicted during bronchiectasis exacerbations (BEs). Patients with stable bronchiectasis underwent history inquiry, chest high-resolution computed tomography (HRCT), multiple-breath nitrogen wash-out test, spirometry and sputum culture. Patients who experienced BEs underwent these measurements during onset of BEs and 1 week following antibiotics therapy. Sensitivity analyses were performed in mild, moderate and severe bronchiectasis. We recruited 110 bronchiectasis patients between March 2014 and September 2015. LCI demonstrated similar diagnostic value with MMEF% predicted in discriminating moderate-to-severe from mild bronchiectasis. LCI negatively correlated with MMEF% predicted. Both parameters had similar concordance in reflecting clinical characteristics of bronchiectasis and correlated significantly with forced expiratory flow in one second, age, HRCT score, Pseudomonas aeruginosa colonization, cystic bronchiectasis, ventilation heterogeneity and bilateral bronchiectasis. In exacerbation cohort (n = 22), changes in LCI and MMEF% predicted were equally minimal during BEs and following antibiotics therapy. In sensitivity analyses, both parameters had similar diagnostic value and correlation with clinical variables. MMEF% predicted is a surrogate of LCI for assessing bronchiectasis severity.

Both COPD and emphysema are associated with an increased incidence of lung cancer, but the impacts of these comorbidities on lung cancer prognosis are still unclear. Herein, we conducted a meta-analysis to clarify whether the presence of these comorbidities indicates poor survival in patients with lung cancer. A comprehensive search was conducted using PubMed, Embase, Web of Science, ASCO Abstracts and Cochrane library for articles published before 1 June 2015. Papers referenced by the obtained articles were also reviewed. Main outcomes were overall survival (OS) and disease-free survival (DFS) in patients with lung cancer. Pooled hazard ratio (HR) and 95% confidence intervals (CIs) were calculated using random-effects models. Subgroup and sensitivity analyses were also conducted. Of 58 full texts reviewed, 26 met our inclusion criteria that were derived from 21 and seven studies examining the impacts of COPD and emphysema on survival of lung cancer, respectively. Meta-analyses revealed that concomitant COPD was associated with poorer OS (HR, 1.17; 95% CI: 1.10-1.25, n = 20), which was independent of tumour staging, diagnostic criteria of COPD or location, and DFS (HR, 1.52; 95% CI: 1.04-2.23, n = 6) with high heterogeneity (I(2) = 78%). The presence of emphysema in patients with lung cancer predicted worse OS (HR, 1.66; 95% CI: 1.25-2.22, n = 7), but not poorer DFS. The presence of COPD and emphysema are robust predictors of poor survival in patients with lung cancer. Early detection of these diseases should be taken into account for lung cancer surveillance and management., (© 2015 Asian Pacific Society of Respirology.)

Background: Although viral infections are a major cause of exacerbations in patients with chronic airway diseases, their roles in triggering bronchiectasis exacerbations in adults remain unclear. Therefore, we prospectively investigated the incidence and clinical impacts of viral infection in adults with bronchiectasis exacerbations., Methods: The study cohort of 119 adults with bronchiectasis was followed up prospectively for 12 months. Nasopharyngeal swabs and sputum samples were assayed for 16 respiratory viruses, using polymerase chain reaction assays. Symptoms, spirometry, quality of life, bacterial cultures, and inflammatory markers were assessed during steady-state bronchiectasis and exacerbations., Results: A total of 100 exacerbations were captured from 58 patients during 1-year follow-up. Respiratory viruses were found more frequently in nasopharyngeal swabs and sputum during bronchiectasis exacerbations (49 of 100, 49.0%) than during steady state (11 of 58, 18.9%; P < .001). The most common viruses found in patients experiencing exacerbations were coronavirus (19 of 65, 39.2%), rhinovirus (16 of 65, 24.6%), and influenza A/B viruses (16 of 65, 24.6%). Virus-positive exacerbations were associated with a greater increase in markers of systemic and airway inflammation (serum IL-6 and tumor necrosis factor-α; sputum IL-1β and tumor necrosis factor-α) compared with virus-negative exacerbations, but the differences in spirometric indexes, quality of life, and bacterial density were unremarkable. In receiver operating characteristics analysis, serum interferon-γ-induced protein 10 yielded an area under curve of 0.67 (95% CI, 0.53-0.77; P = .018). Furthermore, a greater proportion of patients with virus-positive exacerbations received IV antibiotics., Conclusions: Prevalence of viral infections, detected by polymerase chain reaction assay, is higher in cases of bronchiectasis exacerbations than in steady-state bronchiectasis, suggesting that respiratory viruses play crucial roles in triggering bronchiectasis exacerbations. The potential mechanisms of virus-induced bronchiectasis exacerbations merit further investigations., Trial Registry: ClinicalTrials.gov; No.: NCT01801657; www.clinicaltrials.gov.

Background: Characteristics of lung function impairment in bronchiectasis is not fully understood., Objectives: To determine the factors associated with lung function impairment and to compare changes in spirometry during bronchiectasis exacerbation and convalescence (1 week following 14-day antibiotic therapy)., Methods: We recruited 142 patients with steady-state bronchiectasis, of whom 44 with acute exacerbations in the follow-up were included in subgroup analyses. Baseline measurements consisted of chest high-resolution computed tomography (HRCT), sputum volume, purulence and bacteriology, spirometry and diffusing capacity. Spirometry, but not diffusing capacity, was examined during acute exacerbations and convalescence., Results: In the final multivariate models, having bronchiectasis symptoms for 10 years or greater (OR = 4.75, 95%CI: 1.46-15.43, P = 0.01), sputum culture positive for Pseudomonas aeruginosa (OR = 4.93, 95%CI: 1.52-15.94, P<0.01) and HRCT total score being 12 or greater (OR = 7.77, 95%CI: 3.21-18.79, P<0.01) were the major variables associated with FEV1 being 50%pred or less; and the only variable associated with reduced DLCO was 4 or more bronchiectatic lobes (OR = 5.91, 95%CI: 2.20-17.23, P<0.01). Overall differences in FVC and FEV1 during exacerbations and convalescence were significant (P<0.05), whereas changes in other spirometric parameters were less notable. This applied even when stratified by the magnitude of FEV1 and DLCO reduction at baseline., Conclusion: Significant lung function impairment should raise alert of chest HRCT abnormality and sputum culture positive for Pseudomonas aeruginosa, in patients with predominantly mild to moderate steady-state bronchiectasis. Acute exacerbations elicited reductions in FVC and FEV1. Changes of other spirometric parameters were less significant during exacerbations., Trial Registration: ClinicalTrials.gov NCT01761214.

Chronic obstructive pulmonary disease (COPD) is a common disease that severely threatens human health. Acute exacerbation of COPD (AECOPD) is a major cause of disease progression and death, and causes huge medical expenditures. This consensus statement represents a description of clinical features of AECOPD in the People's Republic of China and a set of recommendations. It is intended to provide clinical guidelines for community physicians, pulmonologists and other health care providers for the prevention, diagnosis, and treatment of AECOPD.

Background: Mechanical ventilation is a life-saving therapy for acute respiratory distress syndrome (ARDS). However, unphysiological lung stress (transpulmonary pressure) and strain (the ratio between inflated volume and functional residual capacity) can induce lung injury. Unfortunately, both stress and strain are not measured directly because of technical limitations but predicted from airway plateau pressure (Pplat) and tidal volume (Vt). Recently, some literatures indicated that Pplat and Vt cannot be good surrogates without distinguishing pulmonary ARDS patients (ARDSp) from extrapulmonary ARDS patients. Analyzing them together might distort the truth. Thus, we established animal models of ARDSp to explore whether lung stress and strain can be surrogated precisely by Pplat and Vt., Methods: Fifteen Beagle dogs were recruited to establish ARDSp models by injection of oleic acids. Esophageal manometry was performed to estimate pleural pressure and lung stress. Functional residual capacity was obtained through computed tomography. In the first stage, Vt was set at 10mL/kg body weight in healthy and injured lungs and then adjusted to achieve lung strain as 1.0, 1.5, and 2.0 in sequence., Results: There was a good linear relationship between lung stress and Pplat in healthy and ARDS lungs (P<0.001). For a given Vt (10mL/kg body weight), the global lung strains varied from 0.197 to 0.416 and 0.467 to 0.715 in healthy individuals and different ARDS patients, respectively. On the contrary, Vt varied remarkably for a given lung strain., Conclusions: Pplat is an adequate surrogate for lung stress, but Vt cannot represent lung strain sufficiently., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: To investigate the changes and pattern of pulmonary function in severe acute respiratory syndrome (SARS) patients during convalescent period., Methods: Pulmonary function tests were performed in 26 SARS convalescent patients regularly every 3 months after their discharge from hospital. The significance of changes in pulmonary function indexes was analyzed., Results: Restrictive pulmonary ventilation function and diffusing dysfunction of the lung were found in one third of the patients during third to sixth month from onset. There was a little improvement in forced vital capacity (FVC), one second forced expiratory volume (FEV(1.0)), functional residual capacity (FRC) and residual volume (RV) as convalescent period was prolonged, but no difference was found between different stages (3-6 months, 6-9 months, 9-12 months, 12-15 months and 15-17 months). Meanwhile, the FEV(1.0)/FVC showed no significant change. However, there was an obvious improvement in total lung capacity (TLC) and diffusing capacity of the lung for carbon monoxide (DLCO) with the elapse of time, and also a significant difference was found between the later stage and the earlier stage., Conclusion: Pulmonary dysfunction is found among some SARS patients after convalescence presenting mainly as restrictive ventilatory function and diffusing capacity abnormality. These dysfunctions would improve gradually with the elapse of time.