Part 1 · Inflammatory Lung Diseases

Lung Abscess

Liquefactive necrosis of lung parenchyma — when conservative management fails and surgery is required.

InflammatorySurgical relevance
Definition

Necrosis of pulmonary tissue with cavity formation (>2 cm) containing debris and fluid, due to microbial contamination. Acute: <6 weeks duration. Chronic: >6 weeks duration.

Pathophysiology and aetiology

Necrotising pneumonia leads to liquefactive necrosis of lung parenchyma. Central necrosis liquefies and communicates with the bronchial tree, producing the classic air-fluid level cavity on imaging.

Table 11 · Organisms causing lung abscess
SettingCommon organisms
Aspiration (most common)Bacteroides, Peptostreptococci, Fusobacterium — anaerobes predominate
ImmunocompromisedKlebsiella, Enterobacter, Pseudomonas, Proteus, Staph aureus
HAP/VAP/Elderly/HIVGram-negatives, Aspergillus, Actinomycosis, Nocardia, Amoeba

Common locations: Aspiration abscesses preferentially affect the posterior segment of the RUL, superior segment of the RLL, and left lower lobe — the dependent segments in the recumbent position.

Investigations

Chest X-ray showing right upper to mid zone lung cavity with air fluid level consistent with lung abscess
Fig. 1. PA chest radiograph showing a large right upper to mid zone cavitating lesion with an air-fluid level — the classic radiological appearance of lung abscess. Via Wikimedia Commons. CC BY-SA 4.0.
  • Chest X-ray: consolidation early; classic rounded cavity with air-fluid level when communication with bronchial tree established
  • CT thorax: characterises the abscess, identifies associated pathology, guides drainage
  • Bronchoscopy: rules out bronchial obstruction (tumour, foreign body) and facilitates drainage
  • Sputum/pus analysis: aerobic, anaerobic, fungal, and TB cultures

Treatment

Medical management

Antibiotic therapy

Antibiotic selection depends on causative organism, resistance patterns, and clinical context. Refer to local or national guidelines (e.g., NICE or BTS) for current recommended regimens. Duration is typically 4–6 weeks minimum.

Percutaneous drainage

Performed under radiological guidance (ultrasound, fluoroscopy, or CT). Indicated when:

  • No improvement after 1–2 weeks of antibiotics
  • Solitary, enlarging abscess >6 cm
  • Imminent rupture risk
  • Contamination of contralateral lung threatened
  • Microbiological diagnosis needed

Surgery

Standard indications (lung resection — lobectomy/pneumonectomy):

  • No improvement with treatment >6 weeks (chronic lung abscess)
  • Size >6 cm
  • Sepsis persisting >2 weeks

Special indications:

  • Haemoptysis
  • Suspicion of underlying malignancy
  • Associated bronchopleural fistula
  • Associated empyema requiring surgical management
Surgical note

Lung abscess surgery carries higher risk than elective resection — contaminated field, suppurated lung, and risk of soiling the contralateral lung. Careful lung isolation with a double-lumen tube or bronchial blocker is essential before entering the chest. Anatomical resection (lobectomy) is preferred over wedge or non-anatomical excision.

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