Pleural effusion predominantly presents with breathlessness, but cough and pleuritic chest pain can be a feature. The aetiology of the pleural effusion determines other signs and symptoms.
Postero-anterior chest x-ray will show an effusion of >200 mL of fluid. An ultrasound, chest computed tomography scan, or lateral decubitus study indicates whether the fluid is free-flowing or loculated, and whether or not septations are present.
Aspiration and evaluation of the pleural fluid with biochemistry, cytology, and culture determines the nature of the effusion.
Treatment is based on the nature of the effusion and underlying condition.
Therapeutic thoracentesis with nearly complete removal of the fluid collection alleviates dyspnoea and cough in most circumstances.
A pleural effusion results when fluid collects between the parietal and visceral pleural surfaces of the thorax. A thin layer of fluid is always present in this space for lubrication and ease of movement of the lung during inspiration and expiration. If the normal flow of fluid is disrupted, with either too much fluid produced or not enough removed, then fluid accumulates, resulting in a pleural effusion.
History and exam
Key diagnostic factors
- presence of risk factors
- dullness to percussion
Other diagnostic factors
- pleuritic chest pain
- quieter breath sounds
- decreased or absent tactile fremitus
- congestive heart failure
- pulmonary embolism
- recent coronary artery bypass graft surgery
- recent myocardial infarction
- occupational lung disease
- rheumatoid arthritis
- systemic lupus erythematosus
- renal failure
- drug-induced pleural effusion
- recent ovarian stimulation treatment
1st investigations to order
- postero-anterior and lateral chest x-ray
- pleural ultrasound
- LDH and protein in pleural fluid and serum
- red blood cell count in pleural fluid
- WBC count and differential of pleural fluid
- cytology of pleural fluid
- culture of pleural fluid
- pH of pleural fluid
- glucose in pleural fluid
- protein gradient
- blood culture
- sputum Gram stain and culture
- N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in pleural fluid
Investigations to consider
- pleural fluid cholesterol level
- thoracic CT scan
- thoracic MRI
- helical CT scan
- amylase in pleural fluid
- adenosine deaminase (ADA) level in pleural fluid
- lipid analysis of pleural fluid
- pleural biopsy
- interferon-gamma in pleural fluid and real-time polymerase chain reaction of pleural fluid
- tumour markers in pleural fluid
congestive heart failure
malignant: poor performance status or limited lifespan (Karnofsky score ≤30% or ECOG score of ≥2)
malignant: good performance status (Karnofsky score >30% or ECOG score of 0 or 1)
persistent empyema despite chest tube
recurrent symptomatic malignant effusions
recurrent benign effusion
Orhan Orhan, MBBS BSc MRCP FHEA MSc
Consultant Respiratory Physician
Chelsea and Westminster Hospital NHS Foundation Trust
OO declares that he has no competing interests.
Dr Orhan Orhan would like to gratefully acknowledge Drs Clare Ross, Philip W. Ind, Anob M. Chakrabarti, Richard Light, Amber Degryse, Rachel J. Davies, and Peter M. George, previous contributors to this topic.
RL received speaking fees provided by Cardinal Health; owned stock in Denver Biomaterials until it was purchased by Cardinal Health; received fees for consulting from Denver Biomaterials; and is an author of of references cited in this topic. CR, PWI, AMC, AD, RJD, and PMG declare that they have no competing interests.
Y.C. Gary Lee, MBChB, PhD, FCCP, FRACP
Consultant Chest Physician and Senior Lecturer
Oxford Centre for Respiratory Medicine and University of Oxford Churchill Hospital
YCGL declares that he has no competing interests.
Clare Hooper, MBBS
Pleural Research Registrar
North Bristol Lung Centre
Westbury on Trym
CH declares that she has no competing interests.
Steven Sahn, MD
Professor of Medicine and Director
Division of Pulmonary/Critical Care/Allergy/Sleep Medicine
Medical University of South Carolina
SS declares that he has no competing interests.
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