Empyema Thoracis
On this page
Direct answer
Empyema thoracis is frank pus in the pleural space, the end of a spectrum that begins as a simple parapneumonic effusion and progresses through a fibropurulent stage to an organised stage with a fibrous peel. Simple parapneumonic effusions resolve with antibiotics alone; complicated effusions and empyema need prompt intercostal drainage with targeted antibiotics, and an organised cortex needs surgical decortication. Delay converts a curable effusion into a fibrothorax with permanent lung restriction, which is why the stage, read off pleural fluid pH, glucose and character, drives every management decision.
What you must remember
- Stages: uncomplicated effusion (clear fluid, pH above 7.2, glucose above 40 mg per dL — antibiotics alone); complicated effusion or empyema (turbid pus, pH 7.2 or below, glucose below 40 mg per dL, high lactate dehydrogenase, or positive microbiology — drain); organising stage (fibrous peel trapping the lung — surgery).
- Bacteriology follows the pneumonia: Streptococcus species, Staphylococcus aureus (the classical organism in children and after influenza), anaerobes in aspiration disease, and gram-negative bacilli after instrumentation or surgery; tuberculous empyema is common in India and presents with a thick lymphocyte-rich rind.
- Drainage: image-guided intercostal tube (sizes around 24 to 28 French for pus) with flush placement in the dependent collection; computed tomography or ultrasound guidance reduces misplacement and shortens hospital stay.
- Intrapleural tissue plasminogen activator with deoxyribonuclease (the MIST2 combination) improves drainage and reduces surgery and death in loculated disease — but fibrinolytics alone do not, and randomised data in tuberculous empyema show no benefit.
- Surgery: early video-assisted thoracoscopic decortication is preferred when available for failing drains and multiloculated collections; open thoracotomy and decortication deal with the late organised cortex.
- Antibiotics are prolonged, commonly four to six weeks, guided by culture; tuberculous empyema gets standard antitubercular therapy, with drainage only for sizable collections or collapse, and corticosteroids are not routine.
- Recognise the complications: bronchopleural fistula (an air-fluid level that fails to rise with drainage), empyema necessitatis tracking through the chest wall (classically tuberculous or staphylococcal), rib osteomyelitis, fibrothorax and restricted lung, and amyloidosis.
Where students slip
The geometry question is the imaging trap: empyema is extrapulmonary and lenticular with a split-pleura sign, whereas a lung abscess against the chest wall is round, intrapulmonary and thick-walled. The pH calculation is the second trap: 7.2 is the drainage trigger, read with glucose below 40 and high lactate dehydrogenase. The third is expecting fibrinolytics to fix an organised peel — surgical territory — and the fourth, in the paediatric stem, is forgetting Staphylococcus aureus as the classical childhood organism.
Frequently asked questions
Which pleural fluid findings mandate drainage?
Frank pus, positive Gram stain or culture, pH 7.2 or below, glucose below 40 mg per dL or very high lactate dehydrogenase.
What are the three parapneumonic stages?
Simple exudative effusion, then fibropurulent loculation, then organisation with a fibrous peel over the lung.
Which intrapleural therapy helps loculated empyema?
Combination tissue plasminogen activator with deoxyribonuclease; neither alone shows the benefit, and tuberculous empyema does not respond in trials.
When is surgery required?
For an organised cortex, persistent sepsis with a failing drain, or multiloculated disease — video-assisted thoracoscopic decortication first, open thoracotomy for late disease.
What is empyema necessitatis?
Extension of empyema through the chest wall as a soft, fluctuant swelling, classically with tuberculosis.
Which organism classically causes empyema in children?
Staphylococcus aureus, typically after staphylococcal pneumonia or influenza.