Definition

Tension Pneumothorax Overview:

• Life-threatening condition
• Air accumulation in pleural space
• Lung collapse and increased chest pressure
• One-way valve mechanism – allowing air in during inhalation but preventing its escape during exhalation.

Effects: causes traumatic cardiac arrest due to:

• Ipsilateral lung collapse
• Hypoxia
• Mediastinal shift
• Impaired venous return

Emergency Treatment:

• Immediate action required: medical emergency
• Severe respiratory distress indicates tension pneumothorax
• Oxygen and emergency needle decompression
• Insert large-bore needle (2nd or 3rd intercostal space)
• Gush of air confirms diagnosis

Clinical Situations:

• Ventilated patients
• Trauma patients
• Resuscitation patients (CPR)
• Acute asthma and COPD presentations
• Blocked, clamped, or displaced chest drains
• Patients on non-invasive ventilation
• Patients undergoing hyperbaric oxygen treatment

Aetiology

Causes of Tension Pneumothorax:

• Build-up of air in the pleural space due to one-way valve mechanism.
• Traumatic chest injury (e.g., rib fracture, penetrating chest trauma)
• Medical procedures (e.g., mechanical ventilation, central line placement)
• Underlying lung diseases (e.g., chronic obstructive pulmonary disease)
• Spontaneous pneumothorax

Consequences and Urgency:

• Progressive lung collapse and increased chest pressure.
• Mediastinal shift and compression of heart and major blood vessels.
• A medical emergency requiring immediate intervention.

Risk Factors

Risk Factors for Tension Pneumothorax:

• History of lung disease (e.g., emphysema)
• Individuals on mechanical ventilation
• Those with a history of chest trauma or invasive medical procedures
• Individuals with a history of previous pneumothorax

Pathophysiology

Tension Pneumothorax Mechanism:

• Air enters pleural space but can’t escape
• Increases intrathoracic pressure
• Compresses affected lung
• Shifts mediastinum to opposite side
• Impairs blood flow to heart and venous return
• Leads to cardiovascular compromise
• Results in respiratory failure

Differential Diagnosis

Differential Diagnosis of Tension Pneumothorax:

• Simple pneumothorax
• Pulmonary embolism
• Acute asthma exacerbation
• Acute respiratory distress syndrome (ARDS)
• Cardiac tamponade

Evaluation and Differentiation:

• Comprehensive clinical assessment
• Imaging (e.g., chest X-ray)
• Necessary to distinguish tension pneumothorax from other conditions

Epidemiology

Tension Pneumothorax Epidemiology:

• Relatively uncommon
• Often associated with trauma or medical interventions
• Exact UK-specific epidemiological data not widely available
• Regarded as a critical emergency condition necessitating swift recognition and intervention.

Clinical Presentation

Tension Pneumothorax Signs and Symptoms:

• Sudden-Onset: Symptoms appear suddenly.
• Severe Dyspnea/Tachypnea: Shortness of breath.
• Chest Pain or Tightness: Discomfort in the chest.
• Tachycardia: raised heart rate
• Cyanosis: Bluish skin discoloration.
• Decreased Breath Sounds: On the affected side.
• Hyper-resonant to percussion: on the affected side
• Distended Neck Veins: Visible swelling of neck veins + raised JVP
• Pulsus paradoxus: Pulse weakens during inhalation.
• Hemodynamic Instability: Fluctuations in blood pressure and circulation.
• Tracheal deviation: away from affected side
• Severe Cases: May lead to cardiovascular collapse and loss of consciousness.

Investigations

Diagnostic Investigations for Tension Pneumothorax:

• NONE REQUIRED – should not DELAY treatment
• Chest X-ray: Visualizes the collapsed lung and mediastinal shift.
• Computed Tomography (CT) Scan: Provides detailed imaging.

Important Note: While imaging can confirm the diagnosis, the clinical presentation is often clear enough for an immediate diagnosis. Urgent intervention should not be delayed for confirmatory imaging.

Additional Information:

• Delaying diagnosis by waiting for imaging can be life-threatening.
• Tension pneumothorax is primarily a clinical diagnosis.
• Imaging can confirm the diagnosis, especially in stable patients.
• Chest radiographs may show hemi-diaphragmatic depression, ipsilateral flattening of the heart border, and contralateral mediastinal deviation.

Management

Tension Pneumothorax Management:

• Immediate Management: Needle Decompression or Chest Tube Insertion to relieve pressure and restore cardiac output if cardiac arrest occurs.
• Definitive Treatment: Consider pleurodesis, surgical repair, or monitoring for self-resolving cases.
• Oxygen and Analgesia: Administer high-flow oxygen (SpO₂ >96%) and adequate analgesia
• Prophylactic Antibiotics: Consider for severe trauma cases to prevent post chest drain insertion complications.
• Immediate Chest Decompression: Perform if chest radiography is unavailable and tension pneumothorax is suspected, indicated by specific clinical criteria.
• Decompression Technique: Insert a cannula into the appropriate intercostal space.
• Confirming Diagnosis: Expect an immediate rush of air upon successful decompression.
• Chest Drain Insertion: Within the safe triangle; leave until no air escapes and lung re-expands.
• Surgical Intervention: If air leakage persists after chest drain insertion, consider surgery after 2-4 days.

In the UK, tension pneumothorax management involves prompt emergency medical intervention and hospital care.

Prognosis

Tension Pneumothorax Prognosis and Importance of Prompt Intervention:

• Favourable Prognosis with Timely Treatment:
  • Appropriate and prompt management yields generally good outcomes.
• Delays in Diagnosis/Treatment:
  • Delayed recognition or intervention can result in severe complications:
    • Cardiac arrest
    • Respiratory failure
    • Death
• Early Intervention Benefits:
  • Early intervention improves outcomes.
  • Reduces risk of long-term complications.
• Key Takeaway:
  • Prompt recognition and intervention are critical for positive prognosis.

Complications

Complications of Delayed Tension Pneumothorax Treatment:

• Severe Consequences:
  • Inadequate or delayed treatment can lead to serious outcomes.
• Potential Complications:
  • Cardiac arrest
  • Hypoxia (low oxygen levels)
  • Respiratory failure
  • Tension mediastinal shift
  • Irreversible lung damage
• Fatal Outcome Possibility:
  • In rare cases, tension pneumothorax can be fatal.
• Urgent Recognition and Management:
  • Timely intervention is essential to prevent severe consequences.

References

http://www.oxfordmedicaleducation.com/respiratory/pneumothorax/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4203989/