Traumatic pneumothorax

Background

• Present in 25% of patients with chest trauma

Types

1. Open
   • Communication between pleural space and atmospheric pressure (sucking chest wound)
2. Closed
3. Occult
   • Positive pressure ventilation (e.g. intubation) can convert an occult pneumothorax to a tension pneumothorax

Clinical Features

• Rib fracture and penetrating trauma most common causes
• Isolated pneumothorax does not cause severe symptoms until >40% of hemithorax is occupied

Differential Diagnosis

Pneumothorax Types

• Tension pneumothorax
• Spontaneous pneumothorax
  • Catamenial pneumothorax
• Traumatic pneumothorax
  • Iatrogenic pneumothorax

Thoracic Trauma

• Airway/Pulmonary
  • Bronchial injury
  • Diaphragm injury
  • Hemothorax
  • Pulmonary contusion
  • Tracheal injury
  • Trachobronchial injury
  • Traumatic pneumothorax
    • Tension pneumothorax
• Cardiac/Vascular
  • Cardiac contusion
  • Cardiac trauma
  • Cardiac tamponade
  • Commotio cordis
    • Traumatic aortic transection
• Musculoskeletal
  • Clavicle fracture
    • Clavicle fracture (peds)
  • Flail chest
  • Rib fracture
  • Scapula fracture
  • Scapulothoracic dissociation
  • Sternoclavicular dislocation
  • Sternum fracture
• Other
  • Esophageal injury or Perforation
  • Pneumomediastinum
  • Traumatic asphyxia

Evaluation

• Occult pneumothorax after a stab wound may be delayed for up to 6 hours
  • If patient decompensates, obtain repeat imaging

Clinically Stable

Defined as having all of the following:

• Resp rate < 24
• Heart rate 60-120 beats per minute
• Normal BP
• SaO2 >90% on room air and patient can speak in whole sentences

Workup

• CXR
  • Displaced visceral pleural line without lung markings between pleural line and chest wall
  • Upright is best
    • Expiratory films DO NOT improve accuracy
  • Supine CXR = deep sulcus sign
• CT Chest
  • Very sensitive and specific
• Ultrasound
  • NO comet tail artifact
  • No sliding lung sign
  • Bar Code appearance on M-mode (absence of "seashore" waves)

Estimating Pneumothorax Size

Measuring pneumothoraxes. Line A = lung apex to cupola. Line B = interpleural distance.

• On a conventional, upright posterior-anterior chest radiograph:
  • Very small: <1 cm interpleural distance (confined to upper 1/3 of chest) OR only seen on CT
  • Small: ≤3cm lung apex to cupola (chest wall apex) on CXR
  • Large: >3cm lung apex to cupola (chest wall apex) on CXR

3cm apex to cupola measurement is roughly equivalent to 2cm interpleural distance (at the level of the hilum)

Both roughly correlate with a 50% pneumothorax by volume

Management

Supplemental oxygen with non-rebreather for all

Tension pneumothorax

• Immediate needle thoracostomy followed by chest tube

Open pneumothorax

• Cover wound with three-sided dressing
  • Make sure to avoid complete occlusion (may convert injury to a tension pneumothorax)

Closed traumatic pneumothorax

• Tube thoracostomy indicated if:
  • Cannot be observed closely
  • Requires intubation
  • Will be transported by air or over a long distance
• Observation if:
  • Very small AND does not require mechanical ventilation
  • Unchanged on repeat CXR in 6 hours
• Decision to intubate
  • Intubation can lead to positive pressure which may worsen a stable traumatic pneumothorax
  • If patient stable, perferrable to just perform thoracostomy
  • If GCS < 8 or patient having difficulty, they should be intubated

Adult Chest Tube Sizes

Chest Tube Size	Type of Patient	Underlying Causes
Small (8-14 Fr)	Most spontaneous pneumothorax (primary and secondary) Most iatrogenic pneumothorax	Alveolar-pleural fistulae (small air leak) Iatrogenic air
Medium (20-28 Fr)	Pneumothorax on mechanical ventilation Non-traumatic tension pneumothorax Malignant effusion	Bronchial-pleural fistulae (large air leak) Malignant fluid
Large (36-40 Fr)	Traumatic pneumothorax Empyema	Bleeding (Hemothorax/hemopneumothorax) Thick pus

Disposition

Admit

Special Instructions

Flying

• Can consider flying 2 weeks after full resolution of traumatic pneumothroax

See Also

• Pneumothorax (main)
• Thoracic Trauma
• Hemothorax

References

Authors

Ross Donaldson