Diagnosis

Pleural empyema

Etiology

Cause [idi]

• Bacterial pneumonia -> 50% get pleural effusion -> 5-10% effusions becomes infected -> pleural empyema

• Penetrating chest trauma

• Esophageal rupture

• Bronchogenic carcinoma

• Tuberculosis

• Complication from lung surgery/thoracentesis

• Chest tube placement

• Subdiaphragmatic/liver or paravertebral abscess

Microbiologic agents [idi]

• Streptococcus milleri (S. intermedius, S. constellatus, S. mitis)

• S pneumoniae

• Haemophilus influenzae

• Klebsiella pneumoniae

• Methicillin-resistant Staphylococcus aureus (MRSA)

• Enterobacteria, enterococcus

• Mycobacterium tuberculosis

• Gram-negative organisms and anaerobes

Pathophysiology [idi]

1. Exudative stage: Exudative effusion: rapid fluid accumulation in the pleural space

   • Fever, cough, and pleuritic chest pain

2. Fibrinopurulent stage: Bacterial invasion into the pleural space --> fibrin deposition --> which forms septations and loculations (walled-off bacteria)

   • Worsening chest pain, increased dyspnea, fever, and productive cough

3. Chronic organizational stage:

   • Proliferation of fibroblasts

   • Deposition of a collagen-rich fibrin matrix within the pleural space

   • Resulting in pleural thickening

   • Can cause lung entrapment: Weight loss, cachexia, chronic pain, dyspnea

Risk factors [idi]

• Children and elderly

• Poor oral hygiene

• Alcoholism and IV drug abuse

• Immunocompromised states: HIV, malignancy, diabetes

• Gastroesophageal reflux disease

• Bronchiectasis

• Liver cirrhosis

Complications [idi]

• Pleural fibrosis and fibrothorax

• Bronchopleural fistula

• Sepsis and septic shock

• Respiratory failure

• Recurrent empyema

• Empyema necessitans

• Cardiovascular complications

Epidemiology

Incidence per 100.000 [w1u][es7][2zw][eb7][iat][swb][ikn][ymi][uih]

Approach

• Blood test

• Blood gas

• Blood culture

• Chest X-ray

• Cltrasound

• CT thorax

• Thoracocentesis: culture, Gram stain, PCR, albumin, lactic dehydrogenase, pH

• Pleural fluid analysis --> empyema typically characterized by: [idi]

  • Low pH (<7.2)

  • Low glucose (<60 mg/dL)

  • Elevated LDH (>1000 IU/L)

Treatment

Goal of treatment: [idi][iat]

1. Eradicating infection --> antibiotics

   • Community-acquired empyema: Staphylococcus and Streptococcus species and anaerobes --> 3rd generation cephalosporins + metronidazole

   • Hospital-acquired empyema: S aureus, Pseudomonas, and typical organisms and anaerobes --> vancomycin + metronidazole + antipseudomonal cephalosporin

2. Adequate drainage of the pleural space

   • Tube thoracostomy (removed when drainage falls below 50 mL in 24 hours)

   • Video-assisted thoracoscopic surgery (VATS)

   • Open thoracotomy with decortication

   • Intrapleural therapies: streptokinase, urokinase, tPA, DNase --> some benefit

3. Restoring lung function:

   • Nutritional support

   • Pulmonary rehabilitation: Breathing exercises and physiotherapy

   • Treatment of atelectasis

Differential diagnoses

Abdominal abscess, Boerhaave syndrome, Bronchiolitis obliterans, Chylothorax, Heart failure, Hemothorax, Langerhans cell histiocytosis, Lung abscess, Lung cancer, Pleural effusion, Pleuritis, Pneumonia, Pulmonary embolism, Sarcoidosis, Tuberculosis, Wegener's granulomatosis