Tension Pneumothorax

A 32-year-old man is brought to the emergency department after a motor vehicle collision. He has severe dyspnea and chest pain. He appears distressed and tachypneic. Vital signs show hypotension and tachycardia. On examination, breath sounds are markedly decreased on the right side, and percussion is hyperresonant. The trachea is deviated to the left, and jugular venous distension is present. Diagnosis?

Diagnosis is Right-Sided Tension Pneumothorax.

1. Definition

Tension pneumothorax is a life-threatening accumulation of air under pressure within the pleural space that causes progressive ipsilateral lung collapse and cardiopulmonary compromise.

Increasing intrapleural pressure can produce mediastinal displacement, impaired venous return, reduced cardiac output, obstructive shock, and cardiac arrest.

A one-way valve mechanism commonly contributes, but tension pneumothorax is fundamentally a physiologic diagnosis defined by respiratory or hemodynamic compromise from pressurized pleural air.

2. Etiology

2.1 Traumatic Causes

1.       Blunt chest trauma

2.       Penetrating chest trauma

3.       Rib fracture with lung or pleural injury

4.       Pulmonary injury from high-energy trauma

2.2 Iatrogenic Causes

1.       Positive-pressure ventilation and barotrauma

2.       Central venous catheter insertion

3.       Thoracentesis

4.       Transthoracic or transbronchial lung biopsy

5.       Tracheostomy

6.       Cardiopulmonary resuscitation

2.3 Spontaneous Causes

1.       Primary spontaneous pneumothorax

2.       Secondary spontaneous pneumothorax associated with underlying lung disease

3. Pathophysiology

1.       Air enters the pleural space

2.       Pleural pressure progressively increases

3.       The ipsilateral lung becomes compressed and collapses

4.       Increasing intrathoracic pressure and mediastinal displacement impair venous return to the heart

5.       Preload and cardiac output fall

6.       Hypoxemia and circulatory compromise worsen

7.       Untreated disease progresses to obstructive shock, pulseless electrical activity, and cardiac arrest

Positive-pressure ventilation can accelerate this process because each positive-pressure breath may further increase intrapleural pressure.

4. Clinical Features

4.1 Core Features

1.       Acute severe dyspnea

2.       Pleuritic chest pain

3.       Tachypnea

4.       Tachycardia

5.       Hypoxemia

6.       Hypotension or shock

4.2 Examination Findings

1.       Markedly decreased or absent breath sounds on the affected side

2.       Hyperresonance to percussion

3.       Reduced tactile fremitus

4.       Asymmetric chest expansion

5.       Jugular venous distension

6.       Tracheal deviation away from the affected side, usually a late finding

7.       Cyanosis in advanced disease

8.       Subcutaneous emphysema may occur

Jugular venous distension may be absent in trauma patients with concurrent hypovolemia or hemorrhage.

In the trauma setting, severe respiratory distress, unilateral markedly reduced breath sounds, and hemodynamic deterioration are generally more useful than waiting for classic late findings such as tracheal deviation.

In mechanically ventilated patients, tension pneumothorax may present with sudden hypoxemia, hypotension, increased airway pressures, and reduced lung compliance.

5. Diagnosis

Tension pneumothorax is a clinical diagnosis when suspected pneumothorax is associated with hemodynamic instability and/or severe respiratory compromise.

Do not delay emergency pleural decompression for imaging when clinical suspicion is high and either of these features is present.

5.1 Bedside Lung Ultrasound

Point-of-care ultrasound can rapidly support the diagnosis when immediately available and should not delay treatment.

Findings associated with pneumothorax include:

1.       Absent lung sliding

2.       Absent B-lines

3.       Absent lung pulse

4.       Lung point

Absent lung sliding is not specific for pneumothorax and can occur with apnea, mainstem intubation, pleural adhesions, or severe lung disease.

A lung point is highly specific for pneumothorax, but it may be absent in a very large or tension pneumothorax.

Ultrasound findings must therefore be interpreted with the patient's clinical and hemodynamic status.

5.2 Chest X-ray

Chest radiography may be obtained in a stable patient or when the diagnosis remains uncertain and imaging will not delay necessary treatment.

Possible findings include:

1.       Visible visceral pleural line

2.       Absent peripheral lung markings

3.       Ipsilateral lung collapse

4.       Mediastinal displacement away from the affected side

5.       Depressed or flattened ipsilateral hemidiaphragm

6.       Subcutaneous emphysema

5.3 CT Chest

1.       CT is highly sensitive for detecting pneumothorax and associated thoracic injuries

2.       It is appropriate for hemodynamically stable trauma patients when detailed assessment is required

3.       CT has no role in delaying immediate decompression of clinically suspected tension pneumothorax in a patient with hemodynamic instability or severe respiratory compromise

6. Management

6.1 Immediate Pleural Decompression

A suspected tension pneumothorax causing hemodynamic instability or severe respiratory compromise requires immediate pleural decompression.

Treatment should not be delayed for imaging.

The decompression technique depends on clinical setting, available equipment, operator expertise, patient anatomy, and local trauma protocol.

Options include:

1.       Needle thoracostomy

2.       Simple or finger thoracostomy by appropriately trained clinicians

3.       Immediate tube thoracostomy when it can be performed without delaying decompression

Current thoracic trauma guidance identifies tube thoracostomy as the definitive treatment for traumatic tension pneumothorax. Needle or finger thoracostomy provides rapid emergency decompression when immediate definitive drainage is not yet available.

6.2 Needle Thoracostomy

Needle thoracostomy is commonly used for rapid decompression, particularly in prehospital care or when immediate tube thoracostomy is not available.

Accepted sites vary according to trauma protocol. Common approaches include:

1.       Second intercostal space at the midclavicular line

2.       A lateral approach at the fourth or fifth intercostal space near the anterior axillary line

3.       The fifth intercostal space at the midaxillary line is also recognized in some trauma guidelines

There is no single decompression site that is optimal for every patient. Site selection should consider patient anatomy, chest wall thickness, nearby structures, catheter length, operator familiarity, and the applicable trauma protocol.

A catheter must be long enough to traverse the chest wall and enter the pleural space. Failure to reach the pleural cavity, catheter kinking, obstruction, or displacement can result in unsuccessful decompression.

6.3 Simple or Finger Thoracostomy

Simple or finger thoracostomy can provide rapid and reliable pleural decompression when performed by appropriately trained clinicians.

It may be particularly useful when:

1.       Needle decompression has failed

2.       Needle decompression is unlikely to be effective

3.       The patient is critically unstable or in traumatic cardiac arrest

4.       Appropriate expertise and equipment are immediately available

An open finger thoracostomy is particularly suitable in patients receiving positive-pressure ventilation.

In a spontaneously breathing patient, negative intrapleural pressure can draw atmospheric air through an open thoracostomy. Therefore, if finger or open thoracostomy is performed in a spontaneously breathing patient, it should be followed promptly by tube thoracostomy or appropriate definitive pleural drainage to prevent ongoing air entrainment.

6.4 Definitive Management

Tube thoracostomy is the definitive treatment.

1.       Insert the tube through a lateral chest wall approach, commonly at the fourth to sixth intercostal space between the anterior and midaxillary lines

2.       Connect it to an appropriate pleural drainage system

3.       Confirm clinical improvement and appropriate tube function

4.       Obtain subsequent imaging when the patient's condition permits to assess lung re-expansion, tube position, and associated injuries

6.5 Supportive Care

1.       Follow the trauma primary survey

2.       Provide high-concentration oxygen initially in major trauma with shock or significant hypoxemia, then titrate according to oxygen saturation and, when indicated, arterial blood gas analysis

3.       Support ventilation when required

4.       Treat associated hemorrhage and shock

5.       Establish vascular access and provide appropriate trauma resuscitation

6.       Continuously reassess respiratory and hemodynamic response after decompression

Oxygen is supportive therapy and must not delay pleural decompression.

When tension pneumothorax is suspected, positive-pressure ventilation may rapidly worsen the physiology. If positive-pressure ventilation is required, pleural decompression should occur immediately before or concurrently when feasible.

Life-saving airway management should not be withheld when it is otherwise necessary.

7. Complications

7.1 Complications of Untreated Tension Pneumothorax

1.       Obstructive shock

2.       Severe hypoxemic respiratory failure

3.       Pulseless electrical activity

4.       Cardiac arrest

5.       Death

7.2 Complications of Pleural Decompression

1.       Hemothorax

2.       Lung injury

3.       Intercostal neurovascular injury

4.       Injury to intrathoracic or upper abdominal structures

5.       Infection

6.       Catheter or chest tube malposition

7.       Persistent air leak or bronchopleural fistula

8.       Rare re-expansion pulmonary edema

8. Key Clinical Insight

Acute respiratory distress + hypotension + unilateral markedly decreased breath sounds + hyperresonance after trauma strongly suggests tension pneumothorax.

In a patient with hemodynamic instability or severe respiratory compromise and high clinical suspicion, decompress immediately and do not wait for imaging.

References

1.       Coccolini F, Cremonini C, Moore EE, et al. Thoracic trauma WSES-AAST guidelines. World Journal of Emergency Surgery. 2025;20:78. doi:10.1186/s13017-025-00651-1.

2.       Lyng JW, Ward C, Angelidis M, et al. Prehospital Trauma Compendium: Traumatic Pneumothorax Care: Position Statement and Resource Document of NAEMSP. Prehospital Emergency Care. Published online December 4, 2024. doi:10.1080/10903127.2024.2416978.

3.       American College of Surgeons Committee on Trauma. Advanced Trauma Life Support (ATLS) Student Course Manual. 11th ed. Chicago, IL: American College of Surgeons; 2025.