COPD
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Symptoms, clinical course, functional and biological data during an exacerbation of chronic obstructive pulmonary disease (EXCOPD) have been investigated, but data on physiological changes of respiratory mechanics during a severe exacerbation with respiratory acidosis requiring noninvasive mechanical ventilation (NIMV) are scant. The aim of this study was to evaluate changes of respiratory mechanics in COPD patients comparing data observed during EXCOPD with those observed during stable state in the recovery phase. In 18 COPD patients having severe EXCOPD requiring NIMV for global respiratory failure, we measured respiratory mechanics during both EXCOPD (T0) and once the patients achieved a stable state (T1). ⋯ Moreover, tension-time index (TTdi) significantly improved from the EXCOPD state to the condition of clinical stability (0.156 ± 0.04 at T0 vs. 0.082 ± 0.02 at T1 p < 0.001). During an EXCOPD, the load/capacity of the respiratory pump is impaired, and although the patients exhibit a rapid shallow breathing pattern, this does not necessarily correlate with a TTdi ≥ 0.15. These changes are reverted once they recover from the EXCOPD, despite a large variability between patients.
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There is growing evidence that emphysema on thoracic computed tomography (CT) is associated with poor exercise tolerance in COPD patients with only mild-to-moderate airflow obstruction. We hypothesized that an excessive ventilatory response to exercise (ventilatory inefficiency) would underlie these abnormalities. In a prospective study, 19 patients (FEV1 = 82 ± 13%, 12 Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1) and 26 controls underwent an incremental exercise test. ⋯ Higher [Formula: see text]E/[Formula: see text]CO2 nadir in COPD was associated with emphysema severity (r = 0.63) which, in turn, was related to reduced lung diffusing capacity (r = -0.72) and blunted changes in PBF from rest to exercise (r = -0.69) (p < 0.01). Ventilation "wasted" in emphysematous areas is associated with impaired exercise ventilatory efficiency in mild-to-moderate COPD. Exercise ventilatory inefficiency links structure (emphysema) and function (DLCO) to a key clinical outcome (poor exercise tolerance) in COPD patients with only modest spirometric abnormalities.
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The use of oral and inhaled corticosteroids is associated with increases in the risk of infection, especially pneumonia. The risk of sepsis with corticosteroid treatment in patients with chronic obstructive pulmonary disease (COPD) has been little studied, however. We assessed whether the use of inhaled and oral corticosteroids in COPD is associated with an increase in the risk of sepsis. ⋯ The increase in risk remains for around 5 months after the oral corticosteroid exposure. Among patients treated for COPD, the risk of sepsis is not increased with inhaled corticosteroids, even at high doses, while the risk is increased with oral corticosteroids. This risk should be considered when treating exacerbations of COPD.
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The purpose of this study was to determine whether expression of connective tissue growth factor (CTGF) protein in chronic obstructive pulmonary disease (COPD) is consistent in humans and animal models of COPD and to investigate the role of this protein in lung epithelial cells. CTGF in lung epithelial cells of ex-smokers with COPD was compared with ex-smokers without COPD by immunofluorescence. A total of twenty C57Bl/6 mice and sixteen non-human primates (NHPs) were exposed to cigarette smoke (CS) for 4 weeks. ⋯ Both CTGF and p16 protein expression in lung epithelia are positively associated with the severity of COPD in ex-smokers. These findings show that CTGF is consistently expressed in epithelial cells of COPD lungs. By accelerating lung epithelial senescence, CTGF may block regeneration relative to epithelial cell loss and lead to emphysema.
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This study aimed to explore the different pathogeneses of combined pulmonary fibrosis and emphysema (CPFE) from emphysema and pulmonary fibrosis. The levels of transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), Krebs Von Den Lungen-6 (KL-6), matrix metalloproteinase-9 (MMP-9), tissue inhibitors of metalloproteinases-1 (TIMP-1), cytokeratin 19 fragment (CYFRA21-1), squamous cell carcinoma antigen (SCC), and the telomerase activity in peripheral blood were measured in 38 CPFE patients, 50 pulmonary emphysema patients, and 34 idiopathic pulmonary fibrosis (IPF) patients. The results demonstrated that the levels of VEGF and TGF-β1 in IPF patients were significantly higher than those in emphysema patients (p < 0.05), and no significant differences were detected between CPFE patients and other two groups (p > 0.05). ⋯ Among the three groups, the levels of SCC, MMP-9, TIMP-1, MMP-9/TIMP-1 ratio, and telomerase activity were not different (p > 0.05). Our study showed that VEGF, TGF-β1, KL-6, and CYFRA21-1 may play a role in the pathogenesis of pulmonary fibrosis. The lower levels of KL-6 and CYFRA21-1 in CPFE patients may be one of the reasons why these patients develop emphysema on the basis of fibrosis.