🫁 Empyema Thoracis

(AKA: Pyothorax – pus in pleural space)


🔍 Definition:

Empyema is a collection of pus in the pleural cavity, usually resulting from infection of the pleural space due to parapneumonic effusion, trauma, surgery, or rupture of pulmonary infections.


📚 Etiology:

Source

Examples

Parapneumonic

Pneumonia, lung abscess

Post-surgical

Thoracic surgery, esophageal perforation

Post-traumatic

Penetrating chest injury, hemothorax

Iatrogenic

Thoracentesis, chest tube, central lines

Others

Tuberculosis, subdiaphragmatic abscess rupture



🦠 Microbiology:

  • Community-acquired:
    • Streptococcus pneumoniae, Staphylococcus aureus, anaerobes, Haemophilus influenzae
  • Hospital-acquired / post-op:
    • Pseudomonas, Enterobacteriaceae, MRSA, VRE
  • Tubercular empyema: Mycobacterium tuberculosis


🧬 Pathophysiology – 3 Stages of Empyema:

Stage

Features

1. Exudative

Thin fluid, low cellularity; mostly neutrophils and proteins

2. Fibrinopurulent

Loculated fluid, ↑ LDH, ↓ glucose, ↑ neutrophils, fibrin deposits

3. Organizing

Thick pleural peel, fibroblast proliferation → trapped lung



🧪 Clinical Features:

  • Fever with chills
  • Pleuritic chest pain
  • Cough with or without sputum
  • Dyspnea
  • Decreased breath sounds and dullness to percussion
  • Cachexia in chronic cases


🔬 Investigations:

1. Imaging

Modality

Findings

Chest X-ray

Blunting of costophrenic angle, opacification

Ultrasound (USG)

Loculated fluid, septations (high sensitivity)

CT Thorax

Best for defining loculations, pleural thickening



2. Thoracocentesis and Pleural Fluid Analysis

Parameter

Empyema Findings

Appearance

Thick, purulent fluid

pH

< 7.2 (acidic)

Glucose

< 40 mg/dL (low)

LDH

> 1000 IU/L or >3x serum LDH

Gram stain / Culture

Positive in ~60%, always send anaerobic culture

Cell count

Neutrophil predominance

ADA

High in tubercular empyema



🧑‍⚕️ Management

🧪 A. Medical Management

  • Empiric antibiotics → tailored to culture
    • Community-acquired: Ceftriaxone + clindamycin or metronidazole
    • Hospital-acquired: Piperacillin-tazobactam or meropenem ± vancomycin
    • Duration: 3–6 weeks total (IV ± oral)
  • Anti-TB therapy for tubercular empyema


💉 B. Drainage

  • Intercostal chest tube (pigtail or wide bore) under USG/CT guidance
    • Exudative stage: simple tube drainage often sufficient
    • Fibrinopurulent: may need fibrinolytics (e.g., tPA + DNase)


🛠️ C. Surgery

Indicated if:

  • Loculated empyema not resolving
  • Thick pleural peel with lung entrapment
  • Persistent fever & sepsis despite drainage

Surgical Options:

Procedure

Indication

VATS

Early loculated empyema

Open decortication

Chronic, organizing stage with trapped lung

Thoracotomy

Large collection, failed less invasive methods



⚠️ Complications

  • Bronchopleural fistula
  • Trapped lung (non-expandable)
  • Fibrothorax
  • Sepsis and multi-organ failure
  • Empyema necessitans (chest wall extension)


🧠 Key ICU Considerations

  • Early diagnosis via USG-guided thoracentesis
  • Monitor oxygenation and signs of respiratory compromise
  • Avoid blind chest tube placement
  • Use fibrinolytics in multiloculated effusions
  • Daily chest tube monitoring (drainage amount, air leak, position)


📊 Empyema vs Parapneumonic Effusion (Comparison)

Parameter

Parapneumonic Effusion

Empyema

Appearance

Clear, straw-colored

Purulent

Glucose

>60 mg/dL

<40 mg/dL

pH

>7.2

<7.2

LDH

Mildly elevated

>1000 IU/L or >3x serum

Culture

Usually negative

Often positive

Management

Antibiotics ± drainage

Mandatory drainage + antibiotics