Empyema is defined as the presence of pus in the pleural space.
Risk factors include pneumonia, iatrogenic intervention in the pleural space, diabetes, and alcohol abuse.
In patients with symptoms and signs of infection and a significant pleural effusion, thoracentesis (pleural aspiration) must be performed urgently.
If empyema or a complicated parapneumonic effusion is diagnosed, a chest drain must be inserted urgently.
A prolonged course of antibiotics is also required.
If patients do not improve with antibiotics and drainage of the pleural space, surgery or fibrinolytics should be considered.
Mortality is approximately 15% to 20%.
Empyema is defined as the presence of frank pus in the pleural space. Parapneumonic effusions are effusions caused by an underlying pneumonia. A simple parapneumonic effusion is not infected, whereas a complicated parapneumonic effusion develops once infection has spread to the pleural space. These three conditions represent a spectrum of pleural inflammation in response to infection, ranging from a simple parapneumonic effusion to empyema.
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
- iatrogenic interventions in the pleural space
- thoracic trauma
- immunocompromised state
- comorbid lung disease
- male sex
- older or young age
1st investigations to order
- blood cultures
- WBC count
- chest x-ray
- 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
- thoracic ultrasound
Investigations to consider
- contrast-enhanced thoracic CT
- MRI of thorax
- PET scan
- pleural fluid polymerase chain reaction (PCR)
adults (culture results pending)
children (culture results pending)
adults (culture results available)
children (culture results available)
Athanasia D. Pataka, MRCP
Assistant Professor of Respiratory Medicine
Respiratory Failure Unit
G Papanikolaou Hospital Thessaloniki
Aristotle University of Thessaloniki
ADP declares that she has no competing interests.
Renata L. Riha, BMedSc, MD, FRACP, FRCPE
RLR declares that she has no competing interests.
Najib M. Rahman, DPhil MSc FRCP
Professor of Respiratory Medicine
Director, Oxford Respiratory Trials Unit
Nuffield Department of Medicine, University of Oxford
NMR declares that Roche UK supplied clinical trial supplies and funding for the MIST2 trial that he conducted.
Dr Athanasia D. Pataka, Dr Renata L. Riha, and Dr Najib M. Rahman would like to gratefully acknowledge Dr Eleanor K. Mishra, a previous contributor to this topic. EKM 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.
Nicholas Maskell, MD
Senior Lecturer and Consultant Physician
North Bristol Lung Centre
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
YCGL declares that he has no competing interests.
- Uncomplicated parapneumonic effusion
- Lung abscess
- ACR–SIR–SPR practice parameter for specifications and performance of image-guided percutaneous drainage/aspiration of abscesses and fluid collections (PDAFC)
- The American Association for Thoracic Surgery consensus guidelines for the management of empyema
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