Emerging bronchoscopic treatments for chronic obstructive pulmonary disease

The role and clinical significance of myeloperoxidase (MPO) and TNF-α in prognostic evaluation of T-COPD

PURPOSE

Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory disorder that requires effective biomarkers for assessing disease activity and severity. This study aimed to compare clinical characteristics, inflammatory biomarker levels, and pulmonary function between stable COPD (S-COPD) and treated COPD (T-COPD) patients, with a focus on the prognostic value of inflammatory markers such as TNF-α, MPO, and IL-6.

METHODS

A total of 81 patients were enrolled in the study, including 39 with stable COPD (S-COPD) and 42 with treated COPD (T-COPD). Clinical characteristics, lung function (measured by FEV1%), and inflammatory biomarkers (IL-6, MMP-9, SAA, MPO, TNF-α, and others) were assessed. Inflammatory biomarkers were compared between the two groups, and their associations with pulmonary function were examined using correlation and regression analyses. Prognostic value was assessed using ROC curve analysis.

RESULTS

The T-COPD group exhibited significantly more severe disease, with higher rates of exacerbations, worse quality of life (CAT and mMRC scores), and reduced lung function (FEV1%, 6-minute walk distance). Inflammatory biomarker analysis revealed no significant differences for IL-6, MMP-9, SAA, RDW, LCN2, PLR, and NLR, but TNF-α and MPO were significantly higher in T-COPD patients (P = 0.015 and P = 0.012, respectively). Among these biomarkers, MPO and TNF-α showed strong negative correlations with FEV1% in T-COPD patients (r = -0.521 and r = -0.459, respectively). ROC curve analysis indicated that TNF-α (AUC = 0.821) was the most predictive biomarker, followed by MPO (AUC = 0.785) and IL-6 (AUC = 0.711). Combining TNF-α and MPO provided the best prognostic performance (AUC = 0.878).

CONCLUSION

TNF-α, MPO, and IL-6 are significant biomarkers associated with disease severity and pulmonary function in T-COPD patients. The combination of TNF-α and MPO offers superior prognostic value, suggesting that these biomarkers may serve as useful tools for monitoring disease progression and guiding treatment decisions in treated COPD patients.

Advanced models for respiratory disease and drug studies

The global burden of respiratory diseases is enormous, with many millions of people suffering and dying prematurely every year. The global COVID-19 pandemic witnessed recently, along with increased air pollution and wildfire events, increases the urgency of identifying the most effective therapeutic measures to combat these diseases even further. Despite increasing expenditure and extensive collaborative efforts to identify and develop the most effective and safe treatments, the failure rates of drugs evaluated in human clinical trials are high. To reverse these trends and minimize the cost of drug development, ineffective drug candidates must be eliminated as early as possible by employing new, efficient, and accurate preclinical screening approaches. Animal models have been the mainstay of pulmonary research as they recapitulate the complex physiological processes, Multiorgan interplay, disease phenotypes of disease, and the pharmacokinetic behavior of drugs. Recently, the use of advanced culture technologies such as organoids and lung-on-a-chip models has gained increasing attention because of their potential to reproduce human diseased states and physiology, with clinically relevant responses to drugs and toxins. This review provides an overview of different animal models for studying respiratory diseases and evaluating drugs. We also highlight recent progress in cell culture technologies to advance integrated models and discuss current challenges and present future perspectives.

Identification of Small Airway Epithelium-Related Hub Genes in Chronic Obstructive Pulmonary Disease

Background

Pulmonary small airway epithelia are the primary site of cellular and histological alterations in chronic obstructive pulmonary disease (COPD), while the potential therapeutic hub genes of pulmonary epithelia are rarely identified to elucidate profound alterations in the progression of the disease.

Methods

Microarray dataset of GSE11906 containing small airway epithelia from 34 healthy non-smokers and 33 COPD patients was applied to screen differentially expressed genes (DEGs). Weighted gene correlation network analysis (WGCNA) was further used to identify the hub genes related to clinical features. Moreover, single-cell RNA sequencing data from GSE173896 and GSE167295 dataset were applied to explore the expression and distribution of the hub genes. The expression levels of hub genes in epithelial cells stimulated by cigarette smoke extract (CSE) were detected by RT-qPCR.

Results

Ninety-eight DEGs correlated with clinical features of COPD were identified via limma and WGCNA. Eight hub genes (including AKR1C3, ALDH3A1, AKR1C1, CYP1A1, GPX2, CBR3, AKR1B1 and GSR) that might exert an antioxidant role in COPD process were identified. Single-cell transcriptomic analysis indicated that the expressions of AKRAC3, ALDH3A1, GPX2, CBR3 and AKR1B1 were significantly increased in the COPD group when compared with the normal group. Moreover, we found that the expression of ALDH3A1 was the most abundantly expressed in ciliated cells. RT-qPCR results indicated that the majority of candidate novel genes were significantly elevated when the epithelial cells were exposed to CSE.

Conclusion

Through integrating limma, WGCNA, and protein-protein interaction (PPI) analysis, a total of eight candidate hub genes of pulmonary airway epithelia were identified in COPD. Moreover, single-cell transcriptomic analysis indicated that ALDH3A1 was enriched in ciliated cells, which may provide a new insight into the pathogenesis and treatment of COPD.

Endoscopic Options for Moderate COPD, Chronic Bronchitis, and Uncontrolled Asthma

Until now, interventional therapies for patients with chronic obstructive pulmonary disease have been available in the form of lung volume reduction procedures as end-stage options. Currently, the range of indications is expanding to include earlier stages of the diseases. Lung denervation is available for moderate COPD, and patients with chronic bronchitis are being evaluated for endoscopic goblet cell ablation. Rheoplasty, metered spray cryo technique, and Karakoca resector balloon are used for this indication. But also, for patients with severe uncontrolled asthma, several techniques are available today. In addition to thermoplasty as a long-proven procedure, new and currently under investigation is the targeted lung denervation.Most of these techniques are currently being tested in large pivotal trials and it will soon become clear in which phenotype which technique will be used in the different forms and stages of obstructive diseases. The current paper presents the techniques and the currently available literature.

Nanomedicines Targeting Respiratory Injuries for Pulmonary Disease Management

The respiratory system holds crucial importance in the biology of vertebrate animals. Injuries of the respiratory system caused by viral infections (e.g., by COVID‐19, MERS, and SARS) can lead to severe or lethal conditions. So far there are no effective treatments for respiratory injuries. This represents a highly unmet clinical need, e.g., during the current COVID‐19 pandemic. Nanomedicines have high potential in the treatment of respiratory injuries. In this review, the pathology and clinical treatments of major respiratory injuries, acute lung injury, and acute respiratory distress syndrome are briefly summarized. The review primarily focuses on nanomedicines based on liposomes, solid lipid nanoparticles, polymeric nanoparticles, and inorganic nanoparticles, which are tested in preclinical models for the treatment of respiratory injuries. These nanomedicines are utilized to deliver a variety of therapeutic agents, including corticosteroids, statins, and nucleic acids. Furthermore, nanomedicines are also investigated for other respiratory diseases including chronic obstructive pulmonary disease and asthma. The promising preclinical results of various nanoformulations from these studies suggest the potential of nanomedicines for future clinical management of respiratory viral infections and diseases.

Efficacy and safety of traditional Chinese medicine injections in the treatment of chronic obstructive pulmonary disease: A protocol for systematic review and network meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a widespread, heterogeneous disease characterized by chronic inflammation of the airway and the gradual blockage of air flow due to bronchial obstruction. At present, a large number of traditional Chinese medicine injections (TCMIs) has been applied in the clinical treatment of COPD. However, there is insufficient evidence of evidence-based medicine of the interaction between them. Therefore, the purpose of this study is through the network meta-analysis to evaluate the efficacy and safety of the different TCMIs treatment of COPD, offering reference and evidence for clinical application.

METHODS

We will search 7 databases for randomized controlled trials of TCMI for the COPD, including PubMed, the Cochrane Library, EMbase, China National Knowledge Infrastructure, China Biological Medicine, Chinese Scientific Journals Database, and Wan-fang databases, from the date of the establishment of each database to October 31, 2021. The network meta-analysis will be implemented through Aggregate Data Drug Information System 1.16.8 and Stata 13.0 software. Pulmonary function included forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC will be the primary outcomes, FEV1 as a percentage of the estimated value (FEV1%pred), maximal voluntary ventilation (MVV), MVV as a percentage of the estimated value (MVV%pred), 6 minutes walking distance, The St. George's Respiratory Questionnaire score, and safety/adverse event will be evaluated as secondary outcomes. Mean differences or odds ratios will be used for statistical analysis. We will ensure the reliability of the results through node-split model and heterogeneity analysis. In addition, methodological quality will be evaluated based on the Cochrane Collaboration's tool, and the quality of evidence will be evaluated according to the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

This study will provide reliable evidence for the clinical selection of TCMI in the treatment of COPD.

CONCLUSION

The results of this study will evaluate the efficacy and safety of TCMI in the treatment of COPD, and provide decision-making references for future clinical and scientific research.

lncRNA TUG1 regulates human pulmonary microvascular endothelial cell apoptosis via sponging of the miR-9a-5p/BCL2L11 axis in chronic obstructive pulmonary disease

The aim of the present study was to investigate the function of long non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) in chronic obstructive pulmonary disease and further assess the underlying molecular mechanisms. Flow cytometry analysis was performed to detect cell apoptosis of human pulmonary microvascular endothelial cells (HPMECs) treated with 1% cigarette smoke extract (CSE). The activity of caspase-3 was measured using a Caspase-3 Activity assay kit and the protein expression of cleaved caspase-3, caspase-3 and Bcl-2 like 11 (BCL2L11) were measured using western blotting. Reverse transcription-quantitative PCR (RT-qPCR) was performed to measure the expression of TUG1 mRNA levels in the treated cells. The association between TUG1, the miR-9a-5p/BCL2L11 axis and with miR-9a-5p were predicted and verified using a dual luciferase reporter assay system. The mRNA expression of miR-9a-5p and BCL2L11, and the transfection efficiency were measured by RT-qPCR. The results showed that CSE induced cell apoptosis and increased lncRNA TUG1 expression in HPMECs. CSE significantly reduced the expression of miR-9a-5p in HPMECs compared with the control group. TUG1-short hairpin RNA relieved cell apoptosis induced by CSE by upregulating miR-9a-5p in HPMECs. The present study predicted and verified that BCL2L11 is a direct target of miR-9a-5p. The mRNA expression of BCL2L11 was increased in HPMECs following CSE treatment compared with the control group. miR-9a-5p mimic and BCL2L11-plasmid markedly increased the expression of miR-9a-5p and BCL2L11, respectively. miR-9a-5p mimic reversed the increase in cell apoptosis induced by CSE by inhibiting BCL2L11 expression in HPMECs. To conclude, the present study demonstrated that lncRNA TUG1 exerted roles in cell apoptosis induced by CSE through modulating the miR-9a-5p/BCL2L11 axis.

Evaluation of the curative effects of Bailing capsules for treating chronic obstructive pulmonary disease: A protocol for systematic review and meta-analysis

BACKGROUND

The goal of the present study is to evaluate the efficacy and safety of Bailing capsules, which is a traditional Chinese drug that can improve lung functionality when used to treat chronic obstructive pulmonary disease (COPD) patients.

METHODS

A comprehensive search will be performed on the following primary electronic databases: PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure, and WanFang database. A search of secondary sources includes reference lists of included studies. Two pairs of review authors will screen and scrutinize selected articles. This study will analyze continuous data as mean differences and dichotomous data as odds ratios, both with 95% confidence intervals. A sensitivity analysis will also be conducted to evaluate the stableness of the outcomes. RevMan 5.3 software was adopted to accomplish all the statistical analysis.

RESULTS

The results obtained in this research shall be published in a peer-reviewed journal.

CONCLUSION

Based on the interpretations of the results, useful conclusions will be presented. These conclusions will offer additional insights with useful evidence to assess whether it is viable to use Bailing capsules as an effective and safety treatment option for COPD.

ETHICS AND DISSEMINATION

The present work does not involve any humans or animals; therefore, ethical approval is not needed.

SYSTEMATIC REVIEW REGISTRATION

March 26, 2021.osf.io/kvgbu. (https://osf.io/kvgbu/).

Local drug delivery systems for inflammatory diseases: Status quo, challenges, and opportunities

Inflammation that is not resolved in due course becomes a chronic disease. The treatment of chronic inflammatory diseases involves a long-term use of anti-inflammatory drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, often accompanied by dose-dependent side effects. Local drug delivery systems have been widely explored to reduce their off-target side effects and the medication frequency, with several products making to the market or in development over the years. However, numerous challenges remain, and drug delivery technology is underutilized in some applications. This review showcases local drug delivery systems in different inflammatory diseases, including the targets well-known to drug delivery scientists (e.g., joints, eyes, and teeth) and other applications with untapped opportunities (e.g., sinus, bladder, and colon). In each section, we start with a brief description of the disease and commonly used therapy, introduce local drug delivery systems currently on the market or in the development stage, focusing on polymeric systems, and discuss the remaining challenges and opportunities in future product development.

Chronic obstructive pulmonary disease - diagnosis and management of stable disease; a personalized approach to care, using the treatable traits concept based on clinical phenotypes. Position paper of the Czech Pneumological and Phthisiological Society

This position paper has been drafted by experts from the Czech national board of diseases with bronchial obstruction, of the Czech Pneumological and Phthisiological Society. The statements and recommendations are based on both the results of randomized controlled trials and data from cross-sectional and prospective real-life studies to ensure they are as close as possible to the context of daily clinical practice and the current health care system of the Czech Republic. Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable heterogeneous syndrome with a number of pulmonary and extrapulmonary clinical features and concomitant chronic diseases. The disease is associated with significant mortality, morbidity and reduced quality of life. The main characteristics include persistent respiratory symptoms and only partially reversible airflow obstruction developing due to an abnormal inflammatory response of the lungs to noxious particles and gases. Oxidative stress, protease-antiprotease imbalance and increased numbers of pro-inflammatory cells (mainly neutrophils) are the main drivers of primarily non-infectious inflammation in COPD. Besides smoking, household air pollution, occupational exposure, low birth weight, frequent respiratory infections during childhood and also genetic factors are important risk factors of COPD development. Progressive airflow limitation and airway remodelling leads to air trapping, static and dynamic hyperinflation, gas exchange abnormalities and decreased exercise capacity. Various features of the disease are expressed unequally in individual patients, resulting in various types of disease presentation, emerging as the "clinical phenotypes" (for specific clinical characteristics) and "treatable traits" (for treatable characteristics) concept. The estimated prevalence of COPD in Czechia is around 6.7% with 3,200-3,500 deaths reported annually. The elementary requirements for diagnosis of COPD are spirometric confirmation of post-bronchodilator airflow obstruction (post-BD FEV₁/VCmax <70%) and respiratory symptoms assessement (dyspnoea, exercise limitation, cough and/or sputum production. In order to establish definite COPD diagnosis, a five-step evaluation should be performed, including: 1/ inhalation risk assessment, 2/ symptoms evaluation, 3/ lung function tests, 4/ laboratory tests and 5/ imaging. At the same time, all alternative diagnoses should be excluded. For disease classification, this position paper uses both GOLD stages (1 to 4), GOLD groups (A to D) and evaluation of clinical phenotype(s). Prognosis assessment should be done in each patient. For this purpose, we recommend the use of the BODE or the CADOT index. Six elementary clinical phenotypes are recognized, including chronic bronchitis, frequent exacerbator, emphysematous, asthma/COPD overlap (ACO), bronchiectases with COPD overlap (BCO) and pulmonary cachexia. In our concept, all of these clinical phenotypes are also considered independent treatable traits. For each treatable trait, specific pharmacological and non-pharmacological therapies are defined in this document. The coincidence of two or more clinical phenotypes (i.e., treatable traits) may occur in a single individual, giving the opportunity of fully individualized, phenotype-specific treatment. Treatment of COPD should reflect the complexity and heterogeneity of the disease and be tailored to individual patients. Major goals of COPD treatment are symptom reduction and decreased exacerbation risk. Treatment strategy is divided into five strata: risk elimination, basic treatment, phenotype-specific treatment, treatment of respiratory failure and palliative care, and treatment of comorbidities. Risk elimination includes interventions against tobacco smoking and environmental/occupational exposures. Basic treatment is based on bronchodilator therapy, pulmonary rehabilitation, vaccination, care for appropriate nutrition, inhalation training, education and psychosocial support. Adequate phenotype-specific treatment varies phenotype by phenotype, including more than ten different pharmacological and non-pharmacological strategies. If more than one clinical phenotype is present, treatment strategy should follow the expression of each phenotypic label separately. In such patients, multicomponental therapeutic regimens are needed, resulting in fully individualized care. In the future, stronger measures against smoking, improvements in occupational and environmental health, early diagnosis strategies, as well as biomarker identification for patients responsive to specific treatments are warranted. New classes of treatment (inhaled PDE3/4 inhibitors, single molecule dual bronchodilators, anti-inflammatory drugs, gene editing molecules or new bronchoscopic procedures) are expected to enter the clinical practice in a very few years.

Interventional Bronchoscopy in the Management of Chronic Obstructive Lung Disease

Background:

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation, hyperinflation and reduced gas exchange that lead to progressive dyspnea. Pulmonary rehabilitation, lifestyle changes, pharmacotherapy, long-term oxygen therapy, noninvasive ventilation and surgical therapeutic approaches are the basic management strategies.

Purpose:

In the last 15 years, various bronchoscopic therapeutic modalities have emerged for severe COPD. The aim of this review is to summarize the effects of these bronchoscopic treatments compared with lung rehabilitation and pharmacological therapies.

Methods:

A PubMed search for the eligible studies and reviews on interventional bronchoscopy and COPD has been conducted.

Results:

Bronchoscopic lung volume reduction (LVR) techniques are targeted to reduce hyperinflation. The efficacy of reversible valve implantation has been confirmed in several randomized controlled trials. It provides clinical benefit in the absence of interlobar collateral ventilation. Nonblocking bronchoscopic LVR with coils, thermal vapor or sealants is independent of collateral ventilation but has not been studied sufficiently. Partially irreversible coil implantation leads to parenchymal compression while irreversible LVR with thermal vapor or sealants induce an inflammatory reaction. Targeted lung denervation ablates parasympathetic pulmonary nerves in COPD for sustainable bronchodilation, and liquid nitrogen metered cryospray destroys hyperplastic goblet cells and excessive submucous glands in the central airways to induce mucosal regeneration in chronic bronchitis.

Conclusion:

The best-examined bronchoscopic LVR method is the valve therapy. The data from the other modalities are still limited. Further studies are required to select the patients that will optimally benefit from a particular treatment and to predict and treat the procedure-related complications.

Quantitative Evaluation of Lobar Pulmonary Function of Emphysema Patients with Endobronchial Coils

BACKGROUND

Recent advances in bronchoscopic lung volume reduction offer new therapies for patients with emphysema and hyperinflation. Pulmonary lobe segmentation with quantification of lobar volumes and emphysema severity plays a pivotal role in treatment planning and post-interventional assessment. Computed tomography (CT)-derived lobar volumes could reflect more accurate regional changes in pulmonary function.

OBJECTIVES

The aim of our study is to validate the reliability of an in-house CT Lung Segmentation software (LungSeg; the Hamlyn Centre, Imperial College London, UK) for lung lobar volume and emphysema quantification for chronic obstructive pulmonary disease (COPD) patients.

METHODS

A total of 108 CT scans from subjects who participated in an endobronchial coil treatment trial were included. Lobar volume and emphysema quantification were performed using the LungSeg and Syngo CT Pulmo 3D package (Siemens Healthcare GmbH, Germany). The inter-user reliability of the LungSeg program was investigated. Correlation coefficients and Bland-Altman analyses were used to quantify the inter-software variability. The agreement between CT volume analysis and plethysmography analysis was also examined.

RESULTS

The high intraclass correlation coefficients (mean ICC = 0.98) of the lobar volumes and emphysema indices measured by LungSeg suggest its excellent reproducibility. The LungSeg and Syngo program have good correlation (rho ≥0.94) and agreement for both lobar volume (median difference = 94 mL and LOAnp = 214.6 mL) and emphysema index (median difference ≤1.5% and LOAnp ≤2.03%) calculations. CT analysis provides a higher estimation of total lung capacity (TLCCT) than body plethysmography (TLCpleth), while there is a fair agreement on residual volume (RVCT) by LungSeg as compared with body plethysmography (RVpleth).

CONCLUSIONS

CT-derived lobar volume and emphysema quantification using the LungSeg program is efficient and reliable in allowing lobar volume assessment. LungSeg has low inter-user variability and agrees better with plethysmography for COPD assessment in our study.

Advances in Interventional Pulmonology

Much has changed since the last review of interventional pulmonology (IP) published in this Clinics series. The rate of development of new techniques and their complexities require IP physicians to be constantly maintaining and updating their skill set. International agreed training pathways help ensure that the interventionalists of the present and future have the required knowledge of anatomy, manual dexterity, and clinical judgment to keep up with the continuing advances that are constantly expanding IP's diagnostic and therapeutic boundaries. IP remains one of the most desirable subspecialities in pulmonology, and the technologic advances make the future an exciting one.

Bronchoscopic treatment of emphysema: an update

Chronic obstructive pulmonary disease (COPD) is the major causes of disability and mortality. The efficacy of maximal medical treatment, although effective at the early stages of the disease, becomes limited when extensive alveolar destruction is the main cause of respiratory failure. At this stage of the disease more aggressive options, when feasible, should be considered. Lung transplantation and lung volume reduction surgery (LVRS) are currently available for a selected group of patients. Endoscopic alternatives to LVRS have progressively gained acceptance and are currently employed in patients with COPD. They promote lung deflation searching the same outcome as LVRS in terms of respiratory mechanics, ameliorating the distressing symptom of chronic dyspnea by decreasing the physiological dead space.

Endobronchial Coils for Endoscopic Lung Volume Reduction: Best Practice Recommendations from an Expert Panel

Endobronchial coils are an additional treatment option for lung volume reduction in patients with severe emphysema. Patient selection should be focused on patients with severe emphysema on optimal medical therapy and with evidence of severe hyperinflation. The technique is suitable in a broad range of patients with emphysema; however, patients with paraseptal emphysema, large focal (giant) bullae, significant co-morbidity and airway-predominant disease should be avoided. Treatment involves placing between 10 and 14 coils by bronchoscopy in the selected treatment lobe, with 2 lobes being treated sequentially. Lobe selection for treatment should be based on quantitative computed tomography, and the lobes with the greatest destruction should be targeted (excluding the right middle lobe). The treatment results in an improvement in pulmonary function, exercise performance and quality of life, particularly in patients with severe hyperinflation (residual volume > 200% predicted) and upper-lobe heterogeneous emphysema, but will also be of benefit in lower-lobe predominant and homogeneous emphysema. Finally, it has an acceptable safety profile, although special attention has to be paid to coil-associated opacity which is an inflammatory response that occurs in some patients treated with endobronchial coils.

Functional respiratory imaging: heterogeneity of acute exacerbations of COPD

Background

Exacerbations of COPD are a major burden to patients, and yet little is understood about heterogeneity. It contributes to the current persistent one-size-fits-all treatment. To replace this treatment by more personalized, precision medicine, new insights are required. We assessed the heterogeneity of exacerbations by functional respiratory imaging (FRI) in 3-dimensional models of airways and lungs.

Methods

The trial was designed as a multicenter trial of patients with an acute exacerbation of COPD who were assessed by FRI, pulmonary function tests, and patient-reported outcomes, both in the acute stage and during resolution.

Results

Forty seven patients were assessed. FRI analyses showed significant improvements in hyperinflation (a decrease in total volume at functional residual capacity of −0.25±0.61 L, p≤0.01), airway volume at total lung capacity (+1.70±4.65 L, p=0.02), and airway resistance. As expected, these improvements correlated partially with changes in the quality of life and in conventional lung function test parameters. Patients with the same changes in pulmonary function differ in regional disease activity measured by FRI.

Conclusion

FRI is a useful tool to get a better insight into exacerbations of COPD, and significant improvements in its indices can be demonstrated from the acute phase to resolution even in relatively small groups. It clearly visualizes the marked variability within and between individuals in ventilation and resistance during exacerbations and is a tool for the assessment of the heterogeneity of COPD exacerbations.

Static and dynamic hyperinflation during severe acute exacerbations of chronic obstructive pulmonary disease

Background

Static hyperinflation is known to be increased during moderate acute exacerbations of chronic obstructive pulmonary disease (COPD) (AECOPD), but few data exist in patients with severe exacerbations of COPD. The role of dynamic hyperinflation during exacerbations is unclear.

Methods

In a prospective, observational cohort study, we recruited patients admitted to hospital for AECOPD. The following measurements were performed upon admission and again after resolution (stable state) at least 42 days later: inspiratory capacity (IC), body plethysmography, dynamic hyperinflation by metronome-paced IC measurement, health-related quality of life and dyspnea.

Results

Forty COPD patients were included of whom 28 attended follow-up. The IC was low at admission (2.05±0.11 L) and increased again during resolution by 15.6%±23.1% or 0.28±0.08 L (mean ± standard error of the mean, p<0.01). Testing of metronome-paced changes in IC was feasible, and it decreased by 0.74±0.06 L at admission, similarly to at stable state. Clinical COPD Questionnaire score was 3.7±0.2 at admission and improved by 1.7±0.2 points (p<0.01), and the Borg dyspnea score improved by 2.2±0.5 points from 4.4±0.4 at admission (p<0.01).

Conclusion

Static hyperinflation is increased during severe AECOPD requiring hospitalization compared with stable state. We could measure metronome-paced dynamic hyperinflation during severe AECOPD but found no increase.

Late onset of pneumothorax after bronchoscopic lung volume reduction due to migration of a nitinol coil

The use of Endobronchial coils are a relatively new brochoscopic technique for lung volume reduction. They appear to be safe and effective in improving quality of life, reducing morbidity and mortality related to the primary disease, while avoiding the many risks of morbidity and mortality associated with surgery. Nevertheless, some complications, such as pneumothorax, are relatively common in the periprocedural period. We describe a case of pneumothorax that occurred several days after brochoscopic technique for lung volume reduction due to direct perforation of the visceral pleura by a coil. The patient presented with a large pneumothorax associated with significant air leak, requiring surgical intervention. Exploration of the chest cavity showed a pleural tear caused by a coil. To our knowledge, this is an adverse event that has never been described before, suggesting the possible migration of the coil from the original position.