Haemopneumothorax

Haemopneumothorax is the presence of air and blood together in the pleural space. It is most often due to chest trauma (penetrating or blunt, with rib fracture) and occurs in about a third of those with significant thoracic injury. It may also be spontaneous, or follow a procedure.

Spontaneous haemopneumothorax is found in about 1 to 12% of spontaneous pneumothorax, mostly in young men, from rupture of a vascularised adhesion between the visceral and parietal pleura, or of an apical bulla. Other causes include central line placement, pleural biopsy, anticoagulation, endometriosis and malignancy.

Pathophysiology. Lung laceration (low pressure bleeding that often stops by itself) or injury to the intercostal or internal mammary arteries and the chest wall (high pressure, ongoing bleeding) fills the pleural cavity with blood, while air enters through the lung or chest wall. Blood and air collapse the lung and shift the mediastinum if the volume is large. Retained clot becomes fibrous and traps the lung.

Chest pain, dyspnoea and signs of shock (tachycardia, hypotension, pallor) depending on blood loss. The affected side has reduced air entry, and the percussion note is hyper-resonant over the air and dull over the blood. Subcutaneous emphysema, rib tenderness and flail segment may be present in trauma.

Hypotension, tachycardia, tension signs or an initial blood return of 1500 mL (or ongoing loss) indicates massive haemothorax and requires immediate resuscitation and surgical involvement.

• Clinical assessment in trauma with the primary survey (airway, breathing, circulation).
• Extended focused ultrasound (eFAST) for pleural fluid and pneumothorax at the bedside.
• Erect chest radiograph: air fluid level with a lung edge pulled away from the chest wall. A supine film may show only a diffuse haze, and needs ultrasound or CT.
• CT chest with contrast in the stable patient, showing the volume of blood, active contrast extravasation, lung laceration, rib fracture and associated injuries. Haemothorax of over 300 mL is visible on CT.
• Blood tests: full blood count, group and crossmatch, coagulation, lactate and base deficit.
• Chest tube output: the volume at insertion and the rate over the next hours direct surgical decision.

Differential diagnosis.

• Simple pneumothorax or simple haemothorax
• Haemopneumothorax from aortic or great vessel injury
• Pleural effusion with air from fistula or empyema
• Diaphragmatic rupture with herniation
• Pulmonary contusion

• Resuscitation: oxygen, two large bore intravenous lines, early blood products in massive haemorrhage (balanced red cells, plasma and platelets), and tranexamic acid 1 g intravenously over 10 minutes then 1 g over 8 hours when within 3 hours of injury. Treat pain with multimodal analgesia (paracetamol 1 g every 6 hours, regional block, opioid as needed), since pain impairs breathing.
• Chest drain: a large bore tube (28 to 32 French) in the 5th intercostal space in the anterior to mid-axillary line, connected to an underwater seal (suction 5 to 20 cmH2O if needed). For spontaneous and small cases, 14 to 20 French is often enough.
• Antibiotic prophylaxis for penetrating trauma or drain insertion in trauma: cefazolin 2 g intravenously as a single dose. Tetanus vaccine as indicated.
• Emergency thoracotomy or thoracoscopy for: initial drainage of 1500 mL or more of blood, ongoing loss of over 200 mL per hour for 2 to 4 hours, persistent haemodynamic instability, or ongoing transfusion need. In spontaneous cases, surgery is also needed for ongoing bleeding, to ligate the vessel in the adhesion, and to resect bullae.
• Retained haemothorax (more than a third of the hemithorax or persisting beyond 48 to 72 hours): early video assisted thoracoscopic evacuation within 3 to 7 days, since delay increases empyema and fibrothorax. Intrapleural alteplase 10 mg with dornase alfa 5 mg twice daily for up to 3 days is an option for those unfit for surgery.
• Pleurodesis or bullectomy for spontaneous cases to prevent recurrence.
• Remove the drain when drainage is below 200 mL in 24 hours, the lung is expanded and there is no air leak.
• Rib fracture care: analgesia, early mobilisation, and fixation of flail segments in selected patients.

Complications and prognosis. Retained haemothorax, empyema (up to 5 to 10%), fibrothorax, trapped lung and persistent air leak. Mortality depends on the associated injuries and is high with massive bleeding.

Monitoring. Hourly drain output and vital signs initially, daily radiograph, haemoglobin and clotting, and a radiograph at 1 to 2 weeks after removal. Follow up for dyspnoea and lung function at 6 weeks.

Referral and escalation. Refer immediately to thoracic or trauma surgery for massive or ongoing haemorrhage, and to intensive care for instability.