Hemothorax

Haemothorax is blood in the pleural space, defined by a pleural fluid haematocrit of at least 50% of peripheral haematocrit.

• Causes: trauma (penetrating or blunt with rib fractures, most common), iatrogenic (central venous catheter, thoracentesis, biopsy, surgery), spontaneous (ruptured pleural adhesion with pneumothorax, malignancy, pulmonary arteriovenous malformation, endometriosis: catamenial, coagulopathy, aortic dissection or aneurysm rupture, necrotising infection).
• Massive haemothorax: over 1500 mL (or one third of blood volume) or ongoing loss over 200 mL per hour for 2 to 4 hours; haemorrhagic shock.
• Complications: hypovolaemia, respiratory compromise, retained haemothorax leading to empyema (in 5 to 25%) and fibrothorax with trapped lung.
• Sources: intercostal vessels, internal mammary artery, lung parenchyma (low pressure, usually self limited), great vessels, heart, diaphragm.

• Chest pain, dyspnoea, tachypnoea, tachycardia, hypotension, pallor.
• Dullness to percussion, reduced breath sounds and tactile fremitus on the affected side; neck veins flat (hypovolaemia) or distended (tension).
• Tracheal deviation away in tension haemothorax.
• Associated injuries: rib fractures, pneumothorax, flail chest, pulmonary contusion.

• Chest radiograph (erect shows blunting of costophrenic angle with 200 to 300 mL; supine film shows haziness; need 1000 mL for opacification).
• Extended FAST (eFAST) ultrasound at bedside: anechoic or echogenic pleural collection.
• CT chest for undetected, loculated or retained collections and vascular injury (contrast).
• Chest drain output: initial output over 1500 mL or ongoing over 200 mL/h for 2 to 4 hours indicates need for thoracotomy.
• Pleural fluid haematocrit; haemoglobin, crossmatch, coagulation, lactate.
• Diagnostic aspiration if unclear.

• Resuscitation per ATLS: oxygen, two large bore IV access, balanced blood product resuscitation (1:1:1 packed red cells, plasma, platelets), tranexamic acid 1 g IV within 3 hours then 1 g over 8 hours in trauma.
• Tube thoracostomy (28 to 32 Fr in adults; 5th intercostal space, mid axillary line, anterior to the mid axillary line, within the safe triangle), connected to underwater seal; autotransfusion if available. Antibiotic prophylaxis for penetrating injury (cefazolin 2 g, single dose) is optional.
• Emergency thoracotomy (or video assisted) for: initial drainage of 1500 mL or more, ongoing bleeding over 200 mL/h for 2 to 4 hours (or 1.5 mL/kg/h for 3 hours), haemodynamic instability, or persistent transfusion requirement.
• Retained haemothorax (over 500 mL after 72 hours or incomplete drainage on CT): early video assisted thoracoscopic surgery within 3 to 7 days (reduces empyema and fibrothorax); intrapleural fibrinolysis (alteplase 10 mg with DNase 5 mg twice daily for 3 days) as an alternative.
• Empyema: antibiotics (piperacillin tazobactam 4.5 g every 6 hours), drainage and decortication.
• Pain control (multimodal analgesia, regional blocks) and chest physiotherapy; rib fixation for flail chest.
• Catamenial haemothorax: hormonal suppression (GnRH agonist), pleurodesis, surgery.
• Treat coagulopathy (reverse anticoagulation: prothrombin complex concentrate, vitamin K 10 mg IV).