ERS Statement on Benign Pleural Effusions in Adults.

The incidence of non-malignant pleural effusions (NMPE) far outweighs that of malignant pleural effusions (MPE) and is estimated to be at least 3-fold higher. These so called "benign" effusions do not follow a "benign course" in many cases, with mortality rates matching and sometimes exceeding that of MPEs. In addition to the impact on patients, healthcare systems are significantly affected, with recent US epidemiological data demonstrating that 75% of resource allocation for pleural effusion management is spent on NMPEs (excluding empyema). Despite this significant burden of disease, and by existing at the junction of multiple medical specialties, reflecting a heterogenous constellation of medical conditions, NMPEs are rarely the focus of research or the subject of management guidelines. With this ERS Taskforce, we assembled a multi-specialty collaborative across eleven countries and three continents to provide a Statement based on systematic searches of the medical literature to highlight evidence in the management of the following clinical areas: a diagnostic approach to transudative effusions, heart failure, hepatic hydrothorax, end stage renal failure, benign asbestos related pleural effusion, post-surgical effusion and non-specific pleuritis.

Does previous asbestos exposure increase the risk of a post coronary artery bypass graft (CABG) pleural effusion - a routine data study?

BACKGROUND: Development of pleural effusion (PE) following CABG is common. Post-CABG PE are divided into early- (within 30 days of surgery) and delayed-onset (30 days-1 year) which are likely due to distinct pathological processes. Some experts suggest asbestos exposure may confer an independent risk for late-onset post-CABG PE, however no large studies have explored this potential association. RESEARCH QUESTION: To explore possible association between asbestos exposure and post-CABG PE using routine data. METHODS: All patients who underwent CABG 01/04/2013-31/03/2018 were identified from the Hospital Episode Statistics (HES) Database. This England-wide population was evaluated for evidence of asbestos exposure, pleural plaques or asbestosis and a diagnosis of PE or PE-related procedure from 30 days to 1 year post-CABG. Patients with evidence of PE three months prior to CABG were excluded, as were patients with a new mesothelioma diagnosis. RESULTS: 68,150 patients were identified, of whom 1,003 (1%) were asbestos exposed and 2,377 (3%) developed late-onset PE. After adjusting for demographic data, Index of Multiple Deprivation and Charlson Co-morbidity Index, asbestos exposed patients had increased odds of PE diagnosis or related procedure such as thoracentesis or drainage (OR 1.35, 95% CI 1.03-1.76, p = 0.04). In those with evidence of PE requiring procedure alone, the adjusted OR was 1.66 (95% CI 1.14-2.40, p = 0.01). Additional subgroup analysis of the 518 patients coded for pleural plaques and asbestosis alone revealed an adjusted OR of post-CABG PE requiring a procedure of 2.16 (95% CI 1.38-3.37, p = 0.002). INTERPRETATION: This large-scale study demonstrates prior asbestos exposure is associated with modestly increased risk of post-CABG PE development. The risk association appears higher in patients with assigned clinical codes indicative of radiological evidence of asbestos exposure (pleural plaques or asbestosis). This association may fit with a possible inflammatory co-pathogenesis, with asbestos exposure 'priming' the pleura resulting in greater propensity for PE evolution following the physiological insult of CABG surgery. Further work, including prospective studies and clinicopathological correlation are suggested to explore this further.

Results of the Meso-ORIGINS feasibility study regarding collection of matched benign-mesothelioma tissue pairs by longitudinal surveillance.

OBJECTIVES: To assess key elements of the design for Meso-ORIGINS (Mesothelioma Observational study of RIsk prediction and Generation of paired benign-meso tissue samples, Including a Nested MRI Substudy), an ambitious, UK-wide, prospective study that will collect ≥63 matched benign-mesothelioma tissue pairs through longitudinal surveillance and repeat biopsy of patients with asbestos-associated pleural inflammation (AAPI). DESIGN: A multicentre, mixed-methods feasibility study, comprising a prospective observational element, evaluating recruitment feasibility, technical feasibility of repeat local anaesthetic thoracoscopy (LAT) and patient acceptability, and a retrospective cohort study focused on AAPI-mesothelioma evolution rate, informing sample size. SETTING: 4 UK pleural disease centres (February 2019-January 2020). PARTICIPANTS: Patients with AAPI (history or typical imaging plus appropriate pleural histology) were eligible for both elements. In August 2019, eligibility for the prospective element was broadened, including addition of radiological AAPI for technical feasibility and patient acceptability endpoints only. Retrospective cases required ≥2 years follow-up. OUTCOME MEASURES: A prospective recruitment target was set a priori at 27 histological AAPI cases (or 14 in any 6 months). Technical feasibility and patient acceptability were determined at 6-month follow-up by thoracic ultrasound surrogates and questionnaires, respectively. Retrospective malignant pleural mesothelioma evolution rate was defined by proportion (95% CI). Baseline predictors of evolution were identified using logistic regression. RESULTS: 296 patients with AAPI (39 prospective, 257 retrospective) were recruited/selected. 21/39 prospective recruits were histologically diagnosed (target n=27). Repeat LAT was technically feasible and acceptable in 13/28 (46%) and 24/36 (67%) cases with complete follow-up data. Mesothelioma evolution was confirmed histologically in 36/257 retrospective cases (14% (95% CI 10.3% to 18.8%)) and associated with malignant CT features (OR 4.78 (95% CI 2.36 to 9.86)) and age (OR 1.06 (95% CI 1.02 to 1.12)). CONCLUSIONS: Our initial eligibility criteria were too narrow. Meso-ORIGINS will recruit a broader cohort, including prevalent cases, any biopsy type and patients with malignant CT features. A range of rebiopsy techniques will be allowed, accounting for technical and patient factors. The sample size has been reduced to 500. TRIAL REGISTRATION NUMBER: ISRCTN12840870.

Clinical characteristics of chylothorax: results from the International Collaborative Effusion database.

Background: Chylothorax is an uncommon medical condition for which limited data are available regarding the contemporary aetiology, management and outcomes. The goal of this study was to better define these poorly characterised features. Methods: The medical records of adult patients diagnosed with chylothorax at 12 centres across Europe, America and South Africa from 2009-2021 were retrospectively reviewed. Descriptive and inferential statistics were performed. Results: 77 patients (median age 69 years, male to female ratio 1.5) were included. Subacute dyspnoea was the most typical presenting symptom (66%). The commonest cause of chylothorax was malignancy (68.8%), with lymphoma accounting for 62% of these cases. Other aetiologies were trauma (13%), inflammatory/miscellaneous conditions (11.7%) and idiopathic cases (6.5%). At the initial thoracentesis, the pleural fluid appeared milky in 73%, was exudative in 89% and exhibited triglyceride concentrations >100 mg·dL-1 in 88%. Lymphangiography/lymphoscintigraphy were rarely ordered (3%), and demonstration of chylomicrons in pleural fluid was never ascertained. 67% of patients required interventional pleural procedures. Dietary measures were infrequently followed (36%). No patient underwent thoracic duct ligation or embolisation. Morbidity included infections (18%), and thrombosis in malignant aetiologies (16%). The 1-year mortality was 47%. Pleural fluid protein >3.5 mg·dL-1 (sub-distribution hazard ratio (SHR) 4.346) or lactate dehydrogenase <500 U·L-1 (SHR 10.21) increased the likelihood of effusion resolution. Pleural fluid protein ≤3.5 mg·dL-1 (HR 4.047), bilateral effusions (HR 2.749) and a history of respiratory disease (HR 2.428) negatively influenced survival. Conclusion: Chylothoraces have a poor prognosis and most require pleural interventions. Despite the standard recommendations, lymphatic imaging is seldom used, nor are dietary restrictions followed.

Investigation and outcomes in patients with nonspecific pleuritis: results from the International Collaborative Effusion database.

Introduction: We present findings from the International Collaborative Effusion database, a European Respiratory Society clinical research collaboration. Nonspecific pleuritis (NSP) is a broad term that describes chronic pleural inflammation. Various aetiologies lead to NSP, which poses a diagnostic challenge for clinicians. A significant proportion of patients with this finding eventually develop a malignant diagnosis. Methods: 12 sites across nine countries contributed anonymised data on 187 patients. 175 records were suitable for analysis. Results: The commonest aetiology for NSP was recorded as idiopathic (80 out of 175, 44%). This was followed by pleural infection (15%), benign asbestos disease (12%), malignancy (6%) and cardiac failure (6%). The malignant diagnoses were predominantly mesothelioma (six out of 175, 3.4%) and lung adenocarcinoma (four out of 175, 2.3%). The median time to malignant diagnosis was 12.2 months (range 0.8-32 months). There was a signal towards greater asbestos exposure in the malignant NSP group compared to the benign group (0.63 versus 0.27, p=0.07). Neither recurrence of effusion requiring further therapeutic intervention nor initial biopsy approach were associated with a false-negative biopsy. A computed tomography finding of a mass lesion was the only imaging feature to demonstrate a significant association (0.18 versus 0.01, p=0.02), although sonographic pleural thickening also suggested an association (0.27 versus 0.09, p=0.09). Discussion: This is the first multicentre study of NSP and its associated outcomes. While some of our findings are reflected by the established body of literature, other findings have highlighted important areas for future research, not previously studied in NSP.