Lung ultrasound (LUS) is a safe and portable imaging modality, but the scarcity of data limits the development of machine learning methods for image interpretation and disease monitoring. Existing generative augmentation methods, such as Generative Adversarial Networks (GANs) and diffusion models, often lose subtle diagnostic cues due to resolution reduction, particularly B-lines and pleural irregularities. We propose A trous Wavelet Diffusion (AWDiff), a diffusion based augmentation framework that integrates the a trous wavelet transform to preserve fine-scale structures while avoiding destructive downsampling. In addition, semantic conditioning with BioMedCLIP, a vision language foundation model trained on large scale biomedical corpora, enforces alignment with clinically meaningful labels. On a LUS dataset, AWDiff achieved lower distortion and higher perceptual quality compared to existing methods, demonstrating both structural fidelity and clinical diversity.

Background Eosinophilic pleural effusion (EPE) is a relatively uncommon condition. The objective of this study was to evaluate the clinical, laboratory and radiological features of EPE in a multicentre cohort of patients. Methods This retrospective study included patients with EPE, defined as pleural fluid in which eosinophils constitute ≥10% of the total nucleated cell count, treated between 2009 and 2021 at eight respiratory centres. Predefined data were collected in the International Multicentre Pleural Research Collaborative (IMPACT) registry. Results The study included 210 patients (144 (68.6%) males), with a median age of 67 years (interquartile range (IQR) 55–78 years). Radiological evaluation showed unilateral effusion in 194 (94.2%) patients. Most EPEs (199; 95.7%) were exudates. The median pleural fluid eosinophil percentage was 23% (IQR 14.8–43.3%). The most common aetiologies were malignancy (n=61, 29%), infection (n=43, 20.5%), heart diseases/cardiac intervention (n=17, 8.1%) or trauma (n=16, 7.6%). In 42 (20%) patients, the cause of EPE remained undetermined. In univariate and multivariable analyses incorporating available clinical and laboratory data, EPE was not a significant predictor of either malignancy or benign disease. Conclusion EPE is a nonspecific diagnostic entity and should not, by itself, be regarded as a relevant factor in clinical decision-making.

Background:Pleural fluid cell differentiation is recommended as an initial investigation of undiagnosed unilateral pleural effusions along with routine biochemical, microbiological, and cytological analysis. However, the sensitivity and specificity of cell differentiation from initial pleural aspiration remains unknown. As such, this study aimed to establish the value of pleural cell differentiation in the investigation of undiagnosed pleural effusions. Methods:We performed a prospective study of 1,023 patients presenting to a UK tertiary pleural service with an undiagnosed unilateral pleural effusion between December 2008 and December 2016. Twenty-six patients were excluded due to incomplete data and unclear diagnoses, leaving 997 for analysis. Two respiratory consultants confirmed the diagnosis at 12 months. Cell differentiation was defined according to the British Thoracic Society (BTS) guidelines. Results:The median age of the cohort was 73 years [95% confidence interval (CI): 71-74 years]. Of the 997 patients, 532 (53.4%) were found to have a malignant aetiology and 465 (46.7%) were non-malignant. On review of the pleural fluid cytology, 423 were mixed (42.4%) with no predominant cell type, 352 were lymphocytic (35.3%), 95 were neutrophilic (9.5%), 72 were eosinophilic (7.2%), and 55 were blood-stained (5.5%). Of the lymphocytic effusions, 53.7% had malignant aetiology. A lymphocyte predominance had a sensitivity of 35.5% (95% CI: 31.5-39.8%) and specificity of 65.0% (95% CI: 60.4-69.3%) for malignancy. The majority (80%) of neutrophilic effusions had infectious aetiology with a positive likelihood ratio of 20.6 (95% CI: 12.8-33.1), however, 14% of cases (13/95) had a final diagnosis of malignancy. Of the eosinophilic effusions, 43.0% were also of malignant aetiology, with a positive likelihood ratio of 0.66 (95% CI: 0.42-1.04). Conclusions:This study demonstrated that pleural fluid cell differentiation has limited diagnostic value. Although it may guide towards the likely diagnosis, it lacks diagnostic accuracy as a rule-in/out test and should be used cautiously by clinicians.

Background:CT-guided transthoracic needle aspiration biopsy (CT-TTNAB) is a cornerstone in diagnosing peripheral lung lesions, but iatrogenic pneumothorax (iPTX) is a common, adverse event. The presence of emphysema is a well-known risk factor but emphysema may vary from light to severe, and discrepancy is important for precise prognostic application. Aim:To validate that decreasing the diffusion capacity of carbon monoxide (DLCO) is a significant risk factor for the development of iPTX and need for insertion of a pleural device. Methods:We conducted a retrospective study of patients undergoing CT-TTNAB for suspected lung cancer between 1 January to 31 December 2023. We recorded age, sex, packyears, performance score (PS), FEV1 (%, categorized), FVC (% of predicted) and DLCO categorized into four groups: >80%, 60-79%, 40-59% and <40% of predicted. Association with iPTX and need for insertion of a pleural device were investigated with multiple logistic regression. Results:Of 328 patients undergoing CT-TTNAB, 160 patients developed iPTX. Multiple logistic regression demonstrated that DLCO < 60% was an independent risk factor for both iPTX (DLCO 40-59%: odds ratio (OR) 2.8; <40%: OR 4.8), and chest tube insertion (OR 5.1, respectively, 15.3). Concerning other variables, only FEV1 30-49% was an independent risk factor (OR 6.5 for chest tube insertion). Conclusion:This study adds novel information to the risk assessment before a CT-TTNAB procedure. We suggest that decreasing DLCO expressed <60%predicted is a clinically meaningful risk factor for both the development of iPTX and need for insertion of a pleural device.

Aim:Secondary spontaneous pneumothorax (SSP) most commonly occurs in older patients with known underlying lung disease. Many are frail, but the effect of frailty on outcomes has not been explored previously. This study aims to evaluate the association between frailty and healthcare outcomes in patients with SSP. Methods:Patients with SSP were identified from the national Secure Anonymised Information Linkage databank. Frailty status was assessed using the electronic frailty index. The primary outcome was time from diagnosis to all-cause mortality. Secondary outcomes included time from diagnosis to disease-specific mortality and admission to hospital. Data were analysed using a multilevel Cox proportional hazards regression model, adjusted for age, sex, Welsh Index of Multiple Deprivation, smoking status and comorbidities. Results:Our search identified 3535 individuals diagnosed with SSP between 1 January 2005 and 1 March 2023. By the end of the study, 2102 (59.6%) participants had died with a median follow-up of 683 days (interquartile range 159-1650 days). There was an increasing risk of mortality for those with mild (adjusted hazard ratio (aHR) 1.24, 95% CI 1.10-1.39), moderate (aHR 1.46, 95% CI 1.25-1.70) and severe (aHR 1.83, 95% CI 1.43-2.32) frailty compared to fit individuals. There was also an association between frailty and time to first all-cause hospitalisation, but not disease-specific hospitalisation. Conclusions:Frailty status at diagnosis was an independent predictor of all-cause mortality in patients with SSP. This demonstrates the importance of assessing frailty status to enable clinicians to provide optimised care and make informed decisions about management of patients with SSP.

Introduction Patients receiving extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure (SARF) often experience significant challenges with airway clearance due to disease severity, ultra-protective ventilation strategies and suppression of mucociliary and cough mechanisms. Extremely low tidal volumes and minimal flow rates further hinder secretion mobilisation. Despite increasing global use of ECMO, there is currently no synthesis of evidence describing airway clearance practices, their physiological rationale or outcomes in this population.This scoping review aims to explore the extent and nature of evidence on airway clearance interventions in invasively ventilated adult patients receiving ECMO for SARF. Specific objectives include mapping the types of interventions described and specific parameters, their intended physiological effects, reported outcomes and safety considerations.Methods and analysis This scoping review will be conducted in accordance with the Joanna Briggs Institute methodology and reported using Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. A comprehensive search will be undertaken across Embase, Ovid Emcare, Ovid Medline, CINAHL and grey literature sources including TRIP and Google Scholar. Eligible studies will include original data on airway clearance interventions in adult patients (≥16 years) receiving ECMO for SARF. Studies focused on paediatric populations, extracorporeal carbon dioxide removal, or solely cardiac ECMO will be excluded.Two independent reviewers will screen titles, abstracts and full texts, extract data using a piloted tool and summarise findings using descriptive statistics and narrative synthesis. Basic qualitative content analysis will support mapping of interventions including parameters, their physiological and clinical rationale, and reported outcomes including adverse effects.Ethics and dissemination As this study involves a review of existing literature and does not include collection of primary data, ethical approval is not required. Findings will be disseminated through publication in a peer-reviewed journal and presentation at relevant academic and professional meetings. The results are expected to highlight variations in practice and provide a foundation for future research aimed at optimising respiratory care and improving outcomes for patients receiving ECMO for SARF.Registration osf.io/ptfr7.