Lung abscess
- Some patients with pneumonia develop focal necrosis and a lung abscess
- Particularly occurs in patients with malignancy and malnutrition
- Can also occur following aspiration or inhalation of a foreign body
- Diagnosis can be difficult
Clinical features
- Usually clinical features of pneumonia that fails to improve with antibiotics
- Patient develops pleuritic chest pain and haemoptysis
- Volume of sputum produced may increase
- Patients usually systemically unwell with swinging pyrexia
- Examination usually shows signs of pneumonia
- Commonest complication is an empyema
- Differential diagnosis includes:
- Primary lung neoplasm
- Tuberculosis
- Aspergillosis
- Lung cyst
Investigations
- Chest x-ray may show cavity with air / fluid level
- CT scanning will confirm diagnosis of chest x-ray inconclusive
- Bronchoscopy should be considered to exclude foreign body
Management
- Appropriate antibiotic therapy based on sputum culture result
- Percutaneous aspiration if fails to improve with antibiotics
- For abscesses greater than 5 cm diameter open drainage may be required
- Thoracotomy and lung resection should be considered
Empyema
- Empyema = pus within a body cavity
- Lung empyema usually occurs secondary to pneumonia
- Collection is often multiloculated
- If diagnosis is delayed it will also have a thick, fibrous wall
- Also seen following:
- Oesophageal perforation or rupture
- Blunt or penetrating thoracic trauma
- Nasopharyngeal sepsis that has spread to chest
- Thoracic surgical procedures
Clinical features
- Usually clinical features of pneumonia that fails to improve with antibiotics
- Pleuritic chest pain and breathlessness
- Examination may show clinical features of pleural fluid
- Chest x-ray will show fluid within the pleural cavity
- CT scanning will confirm diagnosis
- Percutaneous aspiration will provide microbiological sample for culture
Management
- Appropriate antibiotic therapy based on sputum culture result
- If fails to resolve will require drainage
- Pleural drainage should be with adequate (28Fr) chest drain
- Thoracoscopy may be required to break down loculi
- Decortication of visceral and parietal pleura may be required to allow lung expansion
- Post-operative adequate drainage is required
- Pneumothorax is not a risk due to resulting pleural scarring
Bibliography
Heffner J E. Infections of the pleural space. Clin Chest Med 1999; 20:607-622.
Rowe S, Cheadle W G. Complications of nosocomial pneumonia in surgical patients. Am J Surg 2000; 197 (Suppl 2A); S63-S68. |