What is hemothorax?

Hemothorax: Definition, Diagnosis, and Management

Hemothorax is a collection of blood in the pleural cavity, which can lead to significant morbidity and mortality if not promptly diagnosed and treated. 1

Definition and Etiology

Hemothorax occurs when blood accumulates in the pleural space between the chest wall and the lung. The most common causes include:

• Traumatic causes (most common):

  • Blunt chest trauma
  • Penetrating chest trauma
  • Iatrogenic (procedures such as central line placement, lung biopsy)

• Non-traumatic causes:

  • Malignancies (e.g., schwannomas in von Recklinghausen disease)
  • Vascular ruptures
  • Anticoagulant use
  • Spontaneous pneumothorax with bleeding
  • Rupture of pleural adhesions 2, 3, 4

Clinical Presentation

Patients with hemothorax typically present with:

• Chest pain
• Shortness of breath (dyspnea)
• Signs of shock in massive hemothorax
• Decreased or absent breath sounds on the affected side
• Dullness to percussion on the affected side 1

Diagnosis

Clinical Assessment

• Assess for history of trauma or invasive procedures
• Evaluate for signs of respiratory distress and hemodynamic instability

Imaging

• Chest X-ray: Traditional first-line imaging
• Ultrasound: Point-of-care ultrasound (eFAST protocol) has high sensitivity and specificity for detecting pleural fluid
• CT scan: More sensitive for detecting small amounts of blood and identifying the source of bleeding 2

Laboratory Evaluation

• If pleural fluid appears bloody, a pleural fluid hematocrit should be obtained
• Diagnostic criteria: Pleural fluid hematocrit >50% of peripheral blood hematocrit confirms hemothorax
• If pleural fluid hematocrit is <1%, the blood in the pleural fluid is not significant 1

Management

Initial Management

1. Stabilize the patient:

   • Ensure airway patency and adequate oxygenation
   • Establish IV access and fluid resuscitation if needed

2. Tube thoracostomy (chest tube placement):

   • Primary treatment for most hemothoraces
   • Large-bore chest tube (28-32 French) placed in the 4th/5th intercostal space in the midaxillary line 1
   • Monitor drainage output

Management Based on Severity

Massive Hemothorax

• Defined as >1,500 mL of blood drained initially or ongoing bleeding >200 mL/hour for 2-4 hours
• Requires immediate surgical intervention (VATS or thoracotomy) with ongoing resuscitation 4

Moderate Hemothorax

• Chest tube drainage with close monitoring
• Consider surgical intervention if inadequate drainage

Retained Hemothorax

• Occurs when blood remains in the pleural space despite chest tube placement
• Can lead to complications including empyema and fibrothorax
• Management options:
  • Intrapleural fibrinolytic therapy to break down clots
  • VATS (within 5 days of the event for best results)
  • Open thoracotomy if other measures fail 2, 3

Complications

• Respiratory distress and failure
• Infection (empyema)
• Fibrothorax (trapped lung)
• Chronic pain
• Procedural complications (pneumothorax, bleeding during thoracentesis) 1, 2

Special Considerations

• Antibiotic prophylaxis for 24 hours is recommended in traumatic hemothorax 4
• Video-assisted thoracoscopic surgery (VATS) has largely replaced open thoracotomy for non-emergent cases, with improved recovery and less post-operative pain 2
• Early intervention for retained hemothorax is crucial to prevent long-term complications 3

Monitoring and Follow-up

• Serial chest imaging to ensure resolution
• Monitor for signs of infection or reaccumulation
• Address underlying cause to prevent recurrence

By following a structured approach to diagnosis and management, the morbidity and mortality associated with hemothorax can be significantly reduced.