Iatrogenic pneumothorax

Background

Causes

• Transthoracic needle aspiration (24%)
• Subclavian vessel puncture (22%)
• Thoracentesis (22%)
• Pleural biopsy (8%)
• Mechanical ventilation (7%)

Clinical Features

Consider in all patients with sudden deterioration after intubation

• Sudden onset pleuritic chest pain
• Tachypnea, hypoxemia, increased work of breathing
• Reduced ipsilateral lung excursion
• Hypotension → tension pneumothorax

Differential Diagnosis

Pneumothorax Types

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

Evaluation

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
    • Lateral decubitus films with suspected side up do increase sensitivity. Good approach in pediatrics to avoid CT
  • Supine CXR = deep sulcus sign
• CT Chest
  • Very sensitive and specific

Management

Supplemental oxygen (non-rebreather mask) initially for all

Unstable

• Needle decompresion followed by chest tube insertion

Stable

Not on Positive Pressure

• Observation (majority) vs. aspiration
• Chest tube if become symptomatic

On Positive Pressure Ventilation

• Needle decompresion followed by chest tube insertion

Needle Aspiration of Pneumothorax

• Use thoracentesis or "pig-tail" kit, if available
• Place in 2nd IC space in midclavicular line or 4th/5th IC space in anterior axillary line
• Withdraw air with syringe until no more can be aspirated
  • Assume a persistent air leak (failure) if no resistance after 4 liters of air has been aspirated AND the lung has not expanded
• Once no further air can be aspirated:
  • Option 1
    • Place closed stopcock and secure catheter to the chest wall
    • Obtain CXR four hours later
    • If adequate lung expansion has occurred, remove catheter
    • Following another two hours of observation, obtain another CXR
    • If the lung remains expanded, may discharge patient
  • Option 2
    • Leave catheter in place
    • Attached a Heimlich (one-way) valve
    • May discharge with follow-up within two days
• If 2.5 L of air has been aspirated, and a significant PTX remains, tube thoracostomy is indicated
• NEJM video on needle aspiration of pneumothorax.

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)	Traumatic pneumothorax Traumatic hemothorax ("any acute hemothorax visible on chest radiograph") Pneumothorax on mechanical ventilation Non-traumatic tension pneumothorax Malignant effusion	Trauma/bleeding (hemothorax/hemopneumothorax) Bronchial-pleural fistulae (large air leak) Malignant fluid
Large (36-40 Fr)	Empyema	Thick pus

Disposition

• See Management section

See Also

• Pneumothorax (main)
• Deterioration After Intubation (DOPE)