Definition

Collection of pus in the pleural space. Frank pus, positive Gram stain, or pleural fluid pH <7.2 with glucose <3.4 mmol/L all indicate empyema requiring drainage regardless of culture result.

Aetiology

Common causes of empyema
CategorySpecific causes
Pulmonary infection (most common)
ParapneumonicS. aureus, E. coli, Pseudomonas, anaerobes
TBPost-primary or post-pneumonectomy
Fungal / parasiticAspergillus, amoeba
Iatrogenic
Post-thoracentesis · post-ICD · post-thoracotomy · post-oesophageal surgery
Traumatic
Penetrating chest trauma · oesophageal rupture · haemothorax
Contiguous spread
Mediastinitis · subdiaphragmatic abscess · paravertebral abscess · ruptured liver abscess
CT chest showing right-sided empyema with pleural thickening and loculated pleural collection
Fig. 1. CT chest showing a right-sided empyema — a loculated pleural collection with thickened enhancing pleural surfaces (split pleura sign), consistent with the fibrinopurulent phase. Via Wikimedia Commons. CC BY-SA 3.0.

Phases of empyema and treatment

Stages of empyema — pathogenesis and management
PhaseTimelinePathogenesisTreatment
Exudative (acute)<2 weeksIncreased pleural permeability — influx of inflammatory cells and protein-rich exudate; fluid is free-flowingAntibiotics · intercostal drainage · early thoracoscopic decortication
Fibrinopurulent (transitional)2–6 weeksProcoagulant activity → fibrin deposition → loculations form; thick pleural rind developingThoracoscopic or open decortication · intrapleural fibrinolytics for loculations
Organising (chronic)>6 weeksFibroblast proliferation → dense fibrous peel → trapped, non-compliant lung; no longer amenable to VATSLong-term open drainage · window thoracostomy · decortication via thoracotomy

Parapneumonic effusion

Develops when inflammatory cells and exudate migrate from infected adjacent lung through altered pleural permeability. Classification: uncomplicated (antibiotic-responsive) vs complicated (requiring drainage). All effusions >1–2 cm on lateral decubitus radiograph must be evaluated by thoracentesis and treated by adequate drainage.

Surgical note — early intervention

The window for VATS decortication closes with the organising phase. Early thoracoscopic intervention in the fibrinopurulent phase — before thick cortex forms — achieves full lung re-expansion with minimal morbidity and shorter hospital stay. Don't wait for the chronic phase hoping the patient will improve on antibiotics alone.

Tubercular empyema

More common in TB-endemic areas. About one-third of patients with pulmonary TB present with pleural effusion or empyema. Acute TB effusion is caused by a delayed hypersensitivity response to mycobacterial antigens following rupture of a subpleural caseous focus. Pleural fluid is lymphocyte-predominant, protein-rich exudate. ADA >40 U/L is strongly predictive for TB in high-prevalence areas.

Chronic TB empyema occurs in poorly treated or immunodeficient patients. Complications: empyema necessitans (decompression through chest wall), bronchopleural fistula, and fibrothorax with chronic functional impairment.

Decortication

Surgical removal of the fibrous peel (cortex) encasing the trapped lung, allowing full re-expansion. The objective is to restore pulmonary function, obliterate the empyema space, and eliminate the septic focus.

VATS decortication

Preferred for fibrinopurulent phase. Requires free-flowing or early-loculated collections. Lower morbidity, shorter LOS. Convert early if exposure is inadequate.

Open decortication

Posterolateral thoracotomy. Standard for organising phase with thick cortex. Better visualisation and leverage for dense peel.

Window thoracostomy

Eloesser flap or rib resection for chronic empyema with BPF, poor surgical risk, or post-pneumonectomy empyema. Long-term open drainage until space heals.

Technical principles

Develop the extra-pleural plane — parietal peel is divided first to enter the empyema cavity. The visceral cortex is then stripped from the lung surface, preserving the visceral pleura where possible to avoid parenchymal air leak. Peel the diaphragm last — dense adhesions here risk diaphragmatic injury. Leave a chest drain with the lung re-expanded before closing.

Thoracoplasty / muscle transposition

Indicated for chronic empyema with a persistent pleural space despite adequate drainage and decortication — particularly post-pneumonectomy empyema or after failed decortication. Thoracoplasty reduces the space by collapsing the chest wall; muscle flaps (serratus anterior, latissimus dorsi, pectoralis major, omentum) fill the residual space and bring a vascular pedicle to aid healing.

Further reading

All clinical content should be verified against current guidelines before clinical application. This resource is intended for revision and educational purposes only.

Standard textbooks

  • Shields TW, LoCicero J, Reed CE, Feins RH. General Thoracic Surgery. 7th ed. Lippincott Williams & Wilkins.
  • Sellke FW, del Nido PJ, Swanson SJ. Sabiston & Spencer Surgery of the Chest. 9th ed. Elsevier.
  • Pearson FG, et al. Thoracic Surgery. 3rd ed. Churchill Livingstone.

Current guidelines & resources