Recently, many researchers paid more attentions to the association between air pollution and chronic obstructive pulmonary disease (COPD). Haze, a severe form of outdoor air pollution, affected most parts of northern and eastern China in the past winter. In China, studies have been performed to evaluate the impact of outdoor air pollution and biomass smoke exposure on COPD; and most studies have focused on the role of air pollution in acutely triggering symptoms and exacerbations. Few studies have examined the role of air pollution in inducing pathophysiological changes that characterise COPD. Evidence showed that outdoor air pollution affects lung function in both children and adults and triggers exacerbations of COPD symptoms. Hence outdoor air pollution may be considered a risk factor for COPD mortality. However, evidence to date has been suggestive (not conclusive) that chronic exposure to outdoor air pollution increases the prevalence and incidence of COPD. Cross-sectional studies showed biomass smoke exposure is a risk factor for COPD. A long-term retrospective study and a long-term prospective cohort study showed that biomass smoke exposure reductions were associated with a reduced decline in forced expiratory volume in 1 second (FEV1) and with a decreased risk of COPD. To fully understand the effect of air pollution on COPD, we recommend future studies with longer follow-up periods, more standardized definitions of COPD and more refined and source-specific exposure assessments.
ObjectiveTo analyze the sensitivity of peak flow meter screening in different subgroups of chronic obstructive pulmonary disease (COPD).
MethodsA total of 156 outpatients with COPD from Peking Union Medical Hospital from May 2013 to December 2014 were recruited in the study. Each patient's symptoms,history of exposure to risk factors,and the times of exacerbation in last year was recorded. All patients completed CAT,mMRC,the St George's Respiratory Questionnaire (SGRQ),6 minutes walking test,spirometry,and peak expiratory flow (PEF) by peak flow meter.
ResultsUsing the cut-off of PEF%pred=80%,the PEF detected 120 COPD patients in 156 subjects. The predictive factors of abnormal PEF%pred in COPD was FEV1%pred and the total score of SGRQ (P<0.05). PEF screening could identify 76.9% of COPD patients,30.0%-60.0% of patients of less symptoms (mMRC<2 or CAT<10 or SGRQ<25),83.3%-90.9% of COPD patients with more symptoms (mMRC ≥ 2 or CAT ≥ 10 or SGRQ ≥ 25),27.7% of COPD patients with mild airflow limitation,68.5% of COPD patients with moderate airflow limitation,83.3% of COPD patients with moderate to very severe airflow limitation. When grouped by GOLD combined assessment method,PEF screening could identify 35.2% of patients of group A,75.0% of patients of group B,and 95.9% of patients of group C and D. The cut-off value of PEF% pred=80% showed low sensitivity to early stage of COPD,but when using the cut-off value of PEF% pred=95%,that sensitivity increased signifcantly.
ConclusionsPeak flow meter may be used as a tool to screen COPD. It can identify part of COPD patients especially for those patients with more symptoms,requiring regular treatment,with deteriorated pulmonary function and high risk of exacerbation.
ObjectivesTo explore the clinical characteristics and risk factors for 30-day mortality of community-acquired pneumonia (CAP) patients with chronic obstructive pulmonary disease (COPD).MethodsThis was a multicentre, retrospective study. Data of patients hospitalized with CAP from four tertiary hospitals in Beijing, Shandong and Yunnan from January 1, 2013 to December 31, 2015 were reviewed. Patients with (COPD-CAP) and without (non COPD-CAP) COPD were compared, including demographic and clinical features, treatment and outcomes. Univariate analysis and multivariate Logistic regression analysis were performed to identify risk factors for 30-day mortality in COPD-CAP patients.ResultsThree thousand three hundred and sixty-six CAP patients were entered into final analysis, COPD-CAP accounted for 12.9% (435/3 366). Compared to non COPD-CAP patients, COPD-CAP patients were more male and more frequent with CURB-65 score 2 and pneumonia severity index (PSI) risk class Ⅲ to Ⅴ. Pseudomonas aeruginosa was the most common etiology and more common in COPD-CAP patients than non COPD-CAP patients. Though the proportion of respiratory failure and heart failure were higher in COPD-CAP patients, there was no significant difference in the 30-day mortality. The 30-day mortality of COPD-CAP patients was 5.7% (25/435). Logistic regression analysis confirmed aspiration (OR 9.505, 95%CI 1.483 - 60.983, P=0.018), blood procalcitonin ≥2.0 ng/mL (OR 5.934, 95%CI 1.162 - 30.304, P=0.032) and PSI risk class (OR 2.533, 95%CI 1.156 - 5.547, P=0.020) were independent risk factors for 30-day mortality in COPD-CAP patients.ConclusionsCOPD-CAP patients present specific characteristics. Besides PSI risk class, clinicians should pay high attention to the aspiration and blood procalcitonin, which could increase the 30-day mortality in COPD-CAP patients.
Objective To explore the clinical value of shear wave elastography in the evaluation of quadriceps femoris lesions in patients with chronic obstructive pulmonary disease (COPD). Methods Fifty-eight COPD patients who were admitted to Chengdu First People’s Hospital and 55 healthy controls were included in the study between August 2021 and February 2022. The thickness, circumference, cross-sectional area and Young's modulus of quadriceps femoris in all subjects were measured using shear wave elastography combined with conventional two-dimensional ultrasound. The differences in ultrasound parameters between the two groups were compared, and the correlation between each ultrasound parameter and clinical evaluation indicators (modified British Medical Research Council Scale, COPD Assessment Test, six-minute walk test, and five-time sit-to-stand test) was analyzed. Results Young’s modulus values of the quadriceps femoris muscle were smaller in the COPD group than those in the healthy control group [COPD Group: rectus femoris 6.72 (6.22, 7.36) kPa, vastus medialis 6.25 (5.82, 6.79) kPa, vastus lateralis 6.94 (6.17, 7.48) kPa; healthy control group: rectus femoris 11.40 (10.23, 12.11) kPa, vastus medialis 10.77 (9.62, 11.42) kPa, vastus lateralis 11.14 (10.42, 12.52) kPa]. The differences were statistically significant (all P<0.05). The Young's modulus value of the rectus femoris muscle correlates with the aforementioned clinical evaluation indicators, with positive correlation with six-minute walk distance and negative correlation with COPD Assessment Test, modified British Medical Research Council Scale, five-time sit-to-stand time (P<0.05). Quadriceps thickness, circumference, and cross-sectional area measured by conventional two-dimensional ultrasound were not significantly different between the two groups, nor were there significant correlations between each parameter and clinical parameters (P>0.05). In addition, shear wave elastography has good reproducibility in the measurement of Young's modulus in quadriceps. Conclusions Shear wave elastography can identify quadriceps lesions earlier than conventional two-dimensional ultrasound in COPD patients, and there is a significant correlation between its measurements and the clinical condition of COPD patients. Shear wave elastography may provide a simple and noninvasive method for clinical evaluation of quadriceps femoris lesions in COPD patients.
ObjectiveTo detect the expression and function of Kv1.3 channel in peripheral blood T lymphocytes of chronic obstructive pulmonary disease (COPD) patients, and to explore the possibility of Kv1.3 channel blockers in treating chronic airway inflammation in patients with COPD.MethodsT lymphocytes were isolated from peripheral blood of COPD patients and healthy controls. Then the mRNA and protein levels of Kv1.3 were detected in T cells. The effects of Kv1.3 channel inhibitors ShK on T cell proliferation and the production of interleukin 2 were detected.ResultsThe Kv1.3 level of peripheral blood T lymphocytes in patients with COPD was significantly higher than that of healthy controls. ShK significantly inhibited the proliferation and interleukin 2 production ability of T lymphocytes.ConclusionsKv1.3 may play important roles in inflammation in COPD. Selective blocking of Kv1.3 channels may be one of the future treatment for COPD.
Objective Sedation and/or analgesia is often applied during noninvasive positive pressure ventilation (NIPPV) to make patients comfortable, and thus improve the synchronization between patients and ventilator. Nevertheless, the effect of sedation and/or analgesia on the clinical outcome of the patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) after extubation remains controversial. Methods A retrospective study was conducted on patients with AECOPD who received NIPPV after extubation in seven intensive care units in West China Hospital, Sichuan University between December 2013 and December 2017 . A logistic regression model was used to analyze the association between the use of sedation and/or analgesia and clinical outcomes including rate of NIPPV failure (defined as the need for reintubation and mechanical ventilation), hospital mortality, and length of intensive care unit stay after extubation. Results A total of 193 patients were included in the analysis, and 62 cases of these patients received sedation and/or analgesia during NIPPV. The usage of sedation and/or analgesia could result in failure of NIPPV (adjusted odd ratio [OR] 0.10, 95% confidence interval [CI] 0.02 - 0.52, P=0.006) and death (adjusted OR=0.13, 95%CI 0.04 - 0.42, P=0.001). Additionally, intensive care unit stay after extubation was longer in the patients who did not receive sedation and/or analgesia than those who did (11.02 d vs. 6.10 d, P< 0.01). Conclusion The usage of sedation and/or analgesia during NIPPV can decrease both the rate of NIPPV failure and hospital mortality in AECOPD patients after extubation.
ObjectiveTo explore the characteristics of induced sputum microbiome in the patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).MethodsInduced sputum samples from 55 patients with AECOPD and 45 patients with stable COPD were analyzed by sequencing of 16S rRNA gene. Microbiota was measured by alpha diversity, beta diversity and LDA effect size analysis (LefSe).ResultsThe microbiome diversity of induced sputum in the AECOPD group was lower than that in the stable COPD group. The microbiome richness in the AECOPD group was higher than that in the stable COPD group. The microbiome structure changed in the AECOPD group compared with the stable COPD group. The proportion of some common pathogens got enriched. The levels of hypersensitive C reactive protein (hs-CRP), interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-α) and Global Initative for Chronic Obstructive Lung Disease (GOLD) grade were negatively related to the diversity of microbiome in the AECOPD group.ConclusionsThe microbiome diversity of induced sputum in AECOPD patients is decreased, and is negatively correlated with the levels of hs-CRP, IL-8, TNF-α and GOLD grade. There are differences in the microbiome structure between AECOPD and stable COPD patients. Some enrichment of common pathogens are found in the induced sputum of patients with AECOPD. These results suggest that there is a significant bacterial dysbiosis in patients with AECOPD.
Objective To investigate the expression and localization of activating transcription factor 3 ( ATF3) and ATF4 in lung of rats with chronic obstructive pulmonary disease ( COPD) , and explore their possible roles in the pathogenesis of COPD. Methods Twenty-two SD rats were randomly divided into a COPD group and a control group. The COPD model was established by cigarette smoking and intratracheal instillation of lipopolysaccharide. The lung function was measured and the pathological changes were observed under light microscope. In situ hybridization, reverse transcription-polymerase chain reaction ( RTPCR), immunohistochemistry, and Western blot techniques were used to detect the mRNA and protein expressions of ATF3 and ATF4 in rat lung. Results The lung function of the COPD group was significantlydecreased. The rats in the COPD group shared specific pathological features of COPD. Immunohistochemical and Western blot results showed that the protein expressions of ATF3 and ATF4 were higher in the COPD group than those in the control group ( P lt;0. 05) . In situ hybridization and RT-PCR results showed that themRNA expressions of ATF3 and ATF4 in the COPD group were also significantly higher than those in the control group ( P lt;0. 05) . Conclusions The expressions of ATF3 and ATF4 are significantly up-regulated in COPD. These findings suggest that ATF3 and ATF4 may play important roles in the oxidative and antioxidative imbalance in the pathogenesis of COPD.
ObjectiveTo explore the effects of simvastatin on the expression of matrix metalloproteinase (MMP) and inflammatory factors in rats with smoke-induced chronic obstructive pulmonary disease (COPD).
Methods40 male Wistar rats were randomly divided into four groups, including a normal group (group A), a simvastatin group (group B), a COPD model group (group C) and a simvastatin intervention group (group D). The COPD model of the group C and D were induced through exposing to the cigarette smoke repeatedly. At the same time, the rats of group B and D were given by gavage 5 mg/(kg·d) with simvastatin, and the other two groups were given with the same volume saline for 16 weeks. Pulmonary function tests and pathological examination of the lung tissue were performed after the induction of COPD model. Enzyme-linked immunosorbent assay (ELISA) method was used to measure the content of MMP-2, MMP-9, IL-6, IL-8, TNF-α in lung tissue homogenate.
ResultsThe airway resistance of group C and group D was significantly higher than the group A and group B (P<0.01), and the airway resistance of group D was significantly lower than group C (P<0.01). The degree of bronchial inflammation and emphysema of group C was more apparent than group D in the pathological section, and there were no bronchial inflammation and emphysema in group A and group B. The ELISA results showed that the contents of MMP-2, MMP-9, IL-6, IL-8, TNF-α in group C were all significantly higher than those in group D.
ConclusionSimvastatin has inhibitory effect on pulmonary inflammation of COPD, and can reduce the expression of matrix metalloproteinase and inflammatory factors in the lung.
ObjectiveTo evaluate the accuracy of the new dynamic approach in the measurement of respiratory mechanics with different pressure support (PS) level during pressure support ventilation (PSV) via oral-nasal mask.MethodsThe Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in patients with chronic obstructive pulmonary disease ［system compliance (Crs)=50 mL/cm H2O, airway resistance (Raw)=20 cm H2O/(L·s), inspiratory time (TI)=1.6 s, breathing rate=15 beats per minute］. PSV were applied with different levels of PS ［positive end-expiratory pressure=5 cm H2O, PS=5/10/15/20/25 cm H2O) and back-up rate=10 beats per minute］. Measurements were conducted at system leaks with 25 – 28 L/min. The performance characteristics and patient-ventilator asynchrony were assessed, including flow, airway pressure, time and workload. Crs and Raw were calculated by using new dynamic approach.ResultsTidal volume (VT) was increased with increasing PS level ［(281.45±4.26)mL at PS 5 cm H2O vs. (456.81±1.91)mL at PS 10 cm H2O vs. (747.45±3.22)mL at PS 20 cm H2O, P<0.01］. Severe asynchronous was occurred frequently when PS is at 25 cm H2O. Inspiration cycling criterion (CC) was up-regulated accompanied by increasing PS level ［(15.62±3.11)% at 5 cm H2O, vs. (24.50±0.77)% at 20 cm H2O, P<0.01］. Premature cycling was always existed during PSV when PS < 20 cm H2O, which could be eliminated as PS level increasing. Delay cycling was found when PS was at 20 cm H2O, and cycling delay time was (33.60±15.91)ms (P<0.01). The measurement of Crs was (46.19±1.57)mL/cm H2O with PS at 10 cm H2O, which was closer to the preset values of simulated lung. The underestimate of Crs was observed during high level PS support. The calculation of inspiratory and expiratory resistance was approximate to 20 cm H2O/(L·s) when PS level was exceeded 15 cm H2O.ConclusionsThe new dynamic approach can continuously assess the respiratory mechanics during non-invasive ventilation, which is no need to interrupt the patient's spontaneous breathing. Higher inspiratory flow during PSV is beneficial for Raw measurement, whereas the accuracy of Crs was influenced by the value of actual VT.
