Pulmonary Contusion (Bruised Lung)

What happens in a pulmonary contusion

A blunt force compresses the chest and the lung against the chest wall, then releases. This damages small blood vessels and the delicate air sacs (alveoli). Blood and fluid leak into the lung tissue and air spaces, so:

• less oxygen passes into the blood
• the lung becomes stiffer and harder to inflate
• inflammation spreads, sometimes to the uninjured lung

Unlike a laceration, there is no tear in the lung surface. Children have flexible ribs, so they can have a significant contusion without rib fractures.

Causes

• motor vehicle crashes, the most common cause
• falls from height
• crush injuries
• assaults and direct blows
• contact sports
• explosions and blast injuries

Pulmonary contusion is present in a substantial share of people with serious blunt chest trauma and frequently occurs with other chest injuries.

Symptoms

• chest pain, especially when breathing in
• shortness of breath and rapid breathing
• cough
• coughing up blood or blood-streaked sputum (hemoptysis)
• wheezing or crackles heard with a stethoscope
• low oxygen levels, a fast heart rate
• bruising of the chest wall

Symptoms may be mild at first and worsen over the first 24 to 72 hours as swelling peaks.

Associated injuries

Diagnosis

• Chest CT: the most sensitive test, showing contusions immediately and their size
• Chest X-ray: may be normal at first; changes often appear within 6 hours
• Pulse oximetry and arterial blood gases: measure oxygen levels
• Ultrasound at the bedside to look for blood or air in the chest
• ECG and troponin if a heart injury is possible

Contusions involving more than about 20 percent of lung volume carry a higher risk of complications.

Treatment

There is no specific treatment for the bruise itself; care supports breathing while the lung heals:

• oxygen to keep blood oxygen levels normal
• pain control: essential to allow deep breathing and coughing, especially with rib fractures. Options include acetaminophen, NSAIDs when safe, opioids and nerve blocks or epidural analgesia
• breathing exercises and incentive spirometry: deep breaths and coughing every hour while awake help prevent pneumonia
• careful IV fluids: avoiding excess fluid that could worsen lung swelling
• chest physiotherapy to clear secretions
• noninvasive ventilation or a ventilator for severe breathing failure
• treating associated injuries: chest drains for pneumothorax or hemothorax, rib fixation surgery for flail chest in selected cases

Antibiotics are used only if pneumonia develops. Steroids are not recommended.

Complications

• pneumonia, the most common complication
• acute respiratory distress syndrome (ARDS)
• respiratory failure needing ventilation
• long-term reduced lung function or scarring in severe cases

Recovery

Mild contusions usually resolve within 3 to 7 days, and most heal within 1 to 2 weeks. Associated rib fractures can take 6 weeks or more to heal. Some people with severe contusions have breathlessness or reduced exercise tolerance for months.

Frequently asked questions

What are the symptoms of a bruised lung?

Common symptoms are chest pain on breathing, shortness of breath, fast breathing, cough and sometimes coughing up blood after a blow to the chest. Symptoms may worsen over the first 1 to 3 days.

How long does a pulmonary contusion take to heal?

Most bruised lungs heal within 1 to 2 weeks, and mild ones within a few days. Recovery takes longer when there are complications such as pneumonia, or associated injuries such as rib fractures.

How is a pulmonary contusion treated?

Treatment is supportive: oxygen, strong pain relief to allow deep breathing, breathing exercises, careful fluid management, and treatment of associated injuries. Severe cases may need ventilator support.

Can a bruised lung be serious?

Yes. Large contusions can cause low oxygen levels, pneumonia, ARDS and respiratory failure. Anyone with breathing difficulty or coughing up blood after a chest injury needs emergency care.