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Last reviewed: 15 Mar 2025
Last updated: 07 Mar 2024

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • recent pneumonia
  • constitutional symptoms
  • pyrexia and rigors
  • dullness to percussion
  • reduced breath sounds and reduced vocal resonance
  • signs of sepsis

Other diagnostic factors

  • subacute presentation
  • productive cough
  • pleuritic chest pain
  • dyspnoea
  • recent instrumentation of the pleural space

Risk factors

  • pneumonia
  • iatrogenic interventions in the pleural space
  • thoracic trauma
  • immunocompromised state
  • comorbid lung disease
  • male sex
  • older or young age

Diagnostic investigations

1st investigations to order

  • blood cultures
  • CRP
  • WBC count
  • metabolic panel
  • chest x-ray
  • thoracic ultrasound
  • thoracentesis: pleural fluid appearance
  • thoracentesis: pleural fluid odour
  • thoracentesis: pleural fluid pH
  • thoracentesis: pleural fluid total protein concentration
  • thoracentesis: pleural fluid LDH level
  • thoracentesis: pleural fluid glucose concentration
  • thoracentesis: pleural fluid white cell differential
  • thoracentesis: pleural fluid microscopy, culture, and sensitivity

Investigations to consider

  • contrast-enhanced thoracic CT
  • MRI of thorax
  • PET scan
  • pleural fluid polymerase chain reaction (PCR)

Treatment algorithm

Contributors

Authors

Christopher Kapp, MD

Assistant Professor of Medicine, Interventional Pulmonologist

Division of Pulmonary and Critical Care, Section of Interventional Pulmonary

Northwestern Memorial Hospital

Chicago

IL

Disclosures

CK declares that he has no competing interests.

Jeremy Kim, MD

Instructor of Medicine, Interventional Pulmonology Fellow

Division of Pulmonary and Critical Care, Section of Interventional Pulmonary

Northwestern Memorial Hospital

Chicago

IL

Disclosures

JK declares that he has no competing interests.

Acknowledgements

Dr Christopher Kapp and Dr Jeremy Kim would like to gratefully acknowledge Dr Athanasia D. Pataka, Dr Renata L. Riha, Dr Najib M. Rahman, and Dr Eleanor K. Mishra, previous contributors to this topic. ADP, RLR, and EKM declare that they have no competing interests. NMR declares that Roche UK supplied clinical trial supplies and funding for the MIST2 trial that he conducted.

Peer reviewers

Steven Sahn, MD

Professor of Medicine and Director

Division of Pulmonary/Critical Care/Allergy/Sleep Medicine

Medical University of South Carolina

Charleston

SC

Disclosures

SS declares that he has no competing interests.

Nicholas Maskell, MD

Senior Lecturer and Consultant Physician

North Bristol Lung Centre

Southmead Hospital

Bristol

UK

Disclosures

NM declares that he has 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

Oxford

UK

Disclosures

YCGL declares that he has no competing interests.

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