Hemothorax

How a hemothorax happens

The pleura are two thin membranes, one covering the lung and one lining the chest wall, with a small amount of fluid between them. When blood vessels in the chest wall, lung, heart or major arteries are injured, blood fills this space. Each side of the chest can hold several liters of blood, enough to cause life-threatening blood loss. The blood also compresses the lung, making breathing harder.

A massive hemothorax means more than about 1.5 liters of blood drained immediately, or continued bleeding of more than about 200 ml an hour. It needs urgent surgery.

Causes

Traumatic

• rib fractures tearing intercostal arteries or lung tissue
• penetrating chest trauma: stab and gunshot wounds
• injuries to the heart, aorta or great vessels
• complications of medical procedures, such as central line insertion, chest drains, biopsies and heart or lung surgery

Non-traumatic (spontaneous)

• blood thinners or bleeding disorders
• cancer of the lung or pleura
• pulmonary embolism with lung infarction
• a ruptured aortic aneurysm
• spontaneous pneumothorax tearing a blood vessel (hemopneumothorax)
• thoracic endometriosis (catamenial hemothorax), with symptoms timed with periods
• tuberculosis and rare vascular conditions

Symptoms

• shortness of breath and rapid breathing
• chest pain, often sharp and worse on breathing in
• fast heart rate and low blood pressure
• pale, cold, clammy skin, anxiety, restlessness or confusion (signs of shock)
• reduced breath sounds and dullness when the doctor taps the chest on the affected side

Small hemothoraces may cause few symptoms and are found on scans.

Diagnosis

• Chest X-ray: shows fluid, often with a blunted angle at the base of the lung. About 300 ml or more is needed to be seen on an upright film.
• Ultrasound (eFAST): used at the bedside in trauma bays to detect blood quickly.
• CT scan: most sensitive, shows the amount of blood, rib fractures and associated injuries.
• Pleural fluid test: fluid with a hematocrit of at least half that of blood confirms a hemothorax.
• Blood tests: blood count, clotting and crossmatch for transfusion.

Treatment

Emergency care

• oxygen and IV access
• blood transfusion for significant blood loss
• reversal of blood thinners if relevant

Chest tube (tube thoracostomy)

A tube is inserted between the ribs into the chest to drain blood and let the lung re-expand. Drainage volume is monitored to decide if surgery is needed. Very small hemothoraces in stable patients may simply be watched.

Surgery

• Thoracotomy (opening the chest) for massive hemothorax or ongoing bleeding
• Video-assisted thoracoscopic surgery (VATS), ideally within 3 to 7 days, to remove retained clotted blood that a tube cannot drain

Other treatments

• Fibrinolytic therapy through the chest tube to break up clots in some cases
• treating the underlying cause, such as cancer or anticoagulation
• pain control and breathing exercises to prevent pneumonia, especially with rib fractures

Complications

• retained hemothorax: clotted blood that does not drain
• empyema: infection of the blood collection
• fibrothorax: scarring that traps the lung and limits breathing, which may need surgical decortication
• hemorrhagic shock from heavy bleeding
• pneumonia

Outlook

With prompt drainage and treatment, most people recover well, and lung function usually returns to normal. Outcomes depend mainly on the severity of associated injuries and how quickly bleeding is controlled.

Frequently asked questions

What causes a hemothorax?

The most common cause is chest trauma, such as rib fractures from a fall or car crash, or stab and gunshot wounds. Other causes include complications of chest procedures, blood thinners, lung cancer, pulmonary embolism and, rarely, endometriosis.

What are the symptoms of a hemothorax?

Symptoms include shortness of breath, chest pain that worsens when breathing in, rapid heartbeat, and signs of blood loss such as dizziness, pale skin and low blood pressure. It is a medical emergency.

What is the difference between hemothorax and pneumothorax?

In a hemothorax, blood fills the space around the lung. In a pneumothorax, air fills that space. Both can collapse the lung, and both can happen together after chest injuries, called a hemopneumothorax.

How is a hemothorax treated?

Most are treated with a chest tube to drain the blood and re-expand the lung. Massive or ongoing bleeding needs emergency surgery, and blood clots that remain may be removed by keyhole surgery (VATS) within the first week.

How long does it take to recover from a hemothorax?

Many people go home within days after the chest tube is removed. Full recovery, especially with rib fractures, can take 4 to 8 weeks. Recovery is longer after surgery or if complications such as infection develop.