Iatrogenic-Dobhoff tube-pneumothorax

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Iatrogenic-Dobhoff tube-pneumothorax

1. Cause

An iatrogenic pneumothorax due to a Dobhoff tube (a type of small-bore, flexible nasogastric feeding tube) occurs when the tube is inadvertently placed into the tracheobronchial tree and perforates the lung parenchyma, causing air to leak into the pleural space.


2. Etiology

This complication is caused by misplacement of the Dobhoff tube during attempted insertion, where instead of advancing into the esophagus and stomach, the tube:

  • Enters the trachea,
  • Travels into a bronchus,
  • Perforates the lung, causing a pneumothorax.

Risk factors include:

  • Impaired gag/cough reflex (e.g., due to sedation, neurologic impairment, or intubation/extubation),
  • Altered mental status,
  • Improper insertion technique or forceful advancement,
  • Absence of fluoroscopic or endoscopic guidance,
  • Overreliance on auscultation or air insufflation to confirm placement.


3. Pathophysiology

When the Dobhoff tube is misplaced into the airway and perforates lung tissue:

  • Air escapes from the alveoli into the pleural space,
  • This leads to a loss of negative intrapleural pressure,
  • The lung partially or completely collapses on the affected side,
  • May progress to tension pneumothorax if air continues to accumulate without an exit.


4. Epidemiology

  • While Dobhoff tubes are commonly used, this is a rare but serious complication.
  • Incidence of pulmonary complications from Dobhoff tube misplacement: ~1-3%.
  • Incidence of pneumothorax specifically: <1%, but likely underreported.
  • More common in critically ill, elderly, or neurologically impaired patients.


5. Clinical Presentation

Varies from asymptomatic to life-threatening. Common signs/symptoms include:

  • Sudden onset of dyspnea,
  • Chest pain,
  • Hypoxia or desaturation,
  • Tachypnea, tachycardia,
  • Decreased or absent breath sounds on the affected side,
  • Subcutaneous emphysema,

Signs of tension pneumothorax (tracheal deviation, hypotension, JVD).


6. Imaging Features

Chest X-ray (CXR) is key in diagnosis:

  • Malpositioned Dobhoff tube (e.g., coiled in bronchus or lung parenchyma),
  • Presence of free air in the pleural space (lucency without lung markings),
  • Collapsed lung on the affected side,
  • May show subcutaneous emphysema or mediastinal shift in tension pneumothorax.

CT Chest (if performed):

  • More precise localization of the tube,
  • Lung perforation or parenchymal damage,
  • Small pneumothoraces are missed on plain film.


7. Treatment

Immediate steps:

  • Stop feeding or suction through the tube,
  • Remove the Dobhoff tube immediately,
  • Administer oxygen,
  • Monitor closely for signs of respiratory distress or deterioration.

If pneumothorax is present:

  • Small, asymptomatic pneumothorax: May observe with serial imaging.
  • Moderate to large or symptomatic pneumothorax:
    • Insert a chest tube (thoracostomy),
    • Admitted for monitoring and supportive care.

If tension pneumothorax is suspected:

  • Immediate needle decompression, followed by chest tube placement.


8. Prognosis

  • Good with prompt recognition and treatment.
  • Most patients recover without long-term issues.
  • Delay in diagnosis may lead to:
    • Respiratory failure,
    • Tension pneumothorax,
    • Cardiac arrest,
    • Increased mortality.
  • Emphasizes the importance of confirming tube placement before use (e.g., X-ray, capnography, pH testing).


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