Hemothorax
Hemothorax is blood in the pleural space, most often from blunt or penetrating chest trauma, defined by a pleural fluid hematocrit above 50% of the peripheral hematocrit. Each hemithorax can hold up to 40% of circulating blood volume, so massive hemothorax is a hemorrhagic-shock emergency treated with simultaneous chest tube thoracostomy and resuscitation, with operative thoracotomy triggered by fixed drainage thresholds.
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What this article covers
- Overview
Blood in the pleural space, almost always from blunt or penetrating chest trauma, defined by pleural fluid with a hematocrit greater than 50% of the peripheral (serum) hematocrit.
- Epidemiology
Trauma is the dominant cause, occurring after both blunt (rib fracture lacerating an intercostal or pulmonary vessel) and penetrating chest injury.
- Risk factors
Blunt or penetrating chest trauma, especially with rib fracture, flail chest, or a wound trajectory crossing the pleural space, the leading risk factor by far.
- Pathophysiology
Direct vascular injury releases blood into the pleural space: laceration of an intercostal artery, the internal mammary artery, a pulmonary vessel, a hilar structure, or the great vessels by a fractured rib end or penetrating object.
- Clinical features
Diminished or absent breath sounds and dullness to percussion over the affected hemithorax are the hallmark findings that localize blood rather than air in the pleural space.
- Differential diagnosis
Tension pneumothorax: hyperresonance rather than dullness, distended (not flat) neck veins, tracheal deviation away from the affected side, and rapidly progressive hemodynamic collapse; treat as a…
- Diagnosis
The diagnosis is confirmed by pleural fluid analysis: a pleural fluid hematocrit greater than 50% of the peripheral (serum) hematocrit defines hemothorax, distinguishing it from a bloody effusion of…
- Management
Start airway, breathing, and circulation management simultaneously with drainage, not in sequence.
- Complications
Hemorrhagic shock and death from ongoing intrathoracic bleeding, the most immediate life threat, particularly with injury to hilar or great-vessel structures.
- Prognosis
Outcome tracks the rate and volume of blood loss and any associated injury (great-vessel, cardiac, tracheobronchial), not the hemothorax alone.
- Prevention
Screen with a chest X-ray or eFAST in every patient with penetrating chest trauma or blunt trauma with a rib fracture, before any hemodynamic decompensation appears.
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