Traumatic pneumothorax

Background

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

Thoracic Trauma

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

Pneumothorax.jpeg
  • CXR
    • Displaced visceral pleural line without lung markings between pleural line and chest wall
    • Upright is best
      • Expiratory films DO NOT improve accuracy[1]
    • 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

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)
  • Alveolar-pleural fistulae (small air leak)
  • Iatrogenic air
Medium (20-28 Fr)
  • Bronchial-pleural fistulae (large air leak)
  • Malignant fluid
Large (36-40 Fr)
  • Bleeding (Hemothorax/hemopneumothorax)
  • Thick pus

Disposition

Admit

Special Instructions

Flying

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

See Also

References

  1. Eur Respir J. 1996 Mar;9(3):406-9
  2. "Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010" British Thoracic Society Guidelines. Thorax 2010;65:ii18-ii31 doi:10.1136/thx.2010.136986 PDF