Pleural effusions are a common medical problem with more than 50 recognised causes including disease local to the pleura or underlying lung, systemic conditions, organ dysfunction and drugs1

Pleural effusions occur as a result of increased fluid formation and/or reduced fluid resorption The precise pathophysiology of fluid accumulation varies according to underlying aetiologies As the differential diagnosis for a unilateral pleural effusion is wide, a systematic approach to investigation is necessary The aim is to establish a diagnosis swiftly while minimising unnecessary invasive investigations and facilitating treatment, avoiding the need for repeated therapeutic aspirations when possible

Since the 2003 guideline, several clinically relevant studies have been published, allowing new recommendations regarding image guidance of pleural procedures with clear benefits to patient comfort and safety, optimum pleural fluid sampling and processing and the particular value of thoracoscopic pleural biopsies This guideline also includes a review of recent evidence for the use of new biomarkers including N-terminal pro-brain natriuretic peptide (NT-proBNP), mesothelin and surrogate markers of tuberculous pleuritis

The history and physical examination of a patient with a pleural effusion may guide the clinician as to whether the effusion is a transudate or an exudate This critical distinction narrows the differential diagnosis and directs further investigation

Clinical assessment alone is often capable of identifying transudative effusions Therefore, in an appropriate clinical setting such as left ventricular failure with a confirmatory chest x-ray, such effusions do not need to be sampled unless there are atypical features or they fail to respond to treatment

Approximately 75% of patients with pulmonary embolism and …

https://thorax.bmj.com/content/thoraxjnl/65/Suppl_2/ii4.full.pdf

Investigation of a unilateral pleural effusion in adults: British Thoracic Society pleural disease guideline 2010

Thoracoscopy under local anaesthetic and intravenous sedation, also known as local anaesthetic thoracoscopy, medical thoracoscopy or pleuroscopy, is increasingly being performed by chest physicians in the UK. In 1999, 11 centres across the UK offered a local anaesthetic thoracoscopy service, increasing to 17 centres in May 20041 and 37 centres in 2009 (Dr N Downer, personal communication). This document, which will use the term ‘local anaesthetic thoracoscopy’, aims to consider the following issues and to make appropriate recommendations on the basis of evidence where available:

Creation of this guideline followed the Appraisal of Guidelines Research and Evaluation/Scottish Intercollegiate Guidelines Network (AGREE/SIGN) methodology of evidence assessment and integration (see introduction to pleural disease guidelines).

Is there a need for a physician-based local anaesthetic thoracoscopy service in the UK? The majority of local anaesthetic thoracoscopy is carried out in the context of an undiagnosed exudative pleural effusion, the commonest cause of which is malignancy.2 This section of the document will therefore focus mainly on local anaesthetic thoracoscopy in the context of malignant disease.

### The increasing burden of pleural disease

Malignant pleural effusion is a common clinical problem. Although the incidence of lung cancer in the UK is falling, the incidence of other cancers is rising. With increasing life expectancy in an ageing population and at current cancer incidence rates, an additional 100 000 cases of cancer per year are expected by 2025.3 Up to 15% of patients who die with malignancy have a pleural effusion at autopsy.4 Studies suggest that exudative effusions are caused by malignancy …

https://thorax.bmj.com/content/thoraxjnl/65/Suppl_2/ii54.full.pdf

Local anaesthetic thoracoscopy: British Thoracic Society pleural disease guideline 2010

Malignant pleural effusions (MPEs) are an important complication for patients with intrathoracic and extrathoracic malignancies. Median survival after diagnosis of an MPE is 4 months. Patients can present with an MPE as a complication of far-advanced cancer or as the initial manifestation of an underlying malignancy. Common cancer types causing MPEs include lymphomas, mesotheliomas, and carcinomas of the breast, lung, gastrointestinal tract, and ovaries. However, almost all tumor types have been reported to cause MPEs. New imaging modalities assist the evaluation of patients with a suspected MPE; however, positive cytologic or tissue confirmation of malignant cells is necessary to establish a diagnosis. Even in the presence of known malignancy, up to 50% of pleural effusions are benign, underscoring the importance of a firm diagnosis to guide therapy. Rapidly evolving interventional and histopathologic techniques have improved the diagnostic yield of standard cytology and biopsy. Management of an MPE remains palliative; it is critical that the appropriate management approach is chosen on the basis of available expertise and the patient's clinical status. This review summarizes the pathogenesis, diagnosis, and management of MPE. Studies in the English language were identified by searching the MEDLINE database (1980-2007) using the search terms pleura, pleural, malignant, pleurodesis, and thoracoscopy.

Recent advances in the diagnosis and management of malignant pleural effusions.

Real-Time Chest Ultrasonography: A Comprehensive Review for the Pulmonologist

Malignant pleural effusions (MPEs) complicate the clinical course of patients with a broad array of malignancies, which are most often due to lymphomas or carcinomas of the breast, lung, gastrointestinal tract or ovaries. Patients may present with a MPE as the initial manifestation of a cancer or develop an effusion during the advanced phases of a known malignancy. In either circumstance, the median survival after presentation with a MPE is 4 months. Effusions may result from direct pleural invasion (MPE) or indirect effects (paraneoplastic effusions), such as impairment of fluid efflux from the pleural space by lymphatic obstruction or pleural effects of cancer radiation or drug therapy. Because only 50% of patients with cancer who develop a pleural effusion during their clinical course have a MPE, careful evaluation of the effusion to establish its aetiology is required to direct therapy. Management is palliative with interventions directed towards decreasing the volume of intrapleural fluid and the severity of associated symptoms.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1440-1843.2007.01154.x

Diagnosis and management of malignant pleural effusions.

https://journal.chestnet.org/article/S0012-3692(15)47631-7/pdf

Andrew J. Peacock

Papers

Investigation of pleural effusion: an evaluation of the new Olympus LTF semiflexible thoracofiberscope and comparison with Abram's needle biopsy.