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Foreign Body in Tracheobronchial tree

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I. Introduction & Epidemiology

  • Definition: Inhalation of an object into the tracheobronchial tree.
  • Age: Peak incidence 1–3 years (oral exploration phase, lack of molars).
  • Site: Right Bronchus (60%) > Left Bronchus.
    • Reason: Right main bronchus is wider, shorter, and more vertical.
  • Nature of Object:
    • Organic (Most common): Peanuts (Vegetable bronchitis), seeds.
      • Risk: Cause severe chemical pneumonitis due to oils (arachidonic acid).
    • Inorganic: Beads, pins, plastic parts.

II. Pathophysiology: Mechanisms of Obstruction

Jackson described 4 types of bronchial obstruction based on the fit of the foreign body (FB):

  1. Bypass Valve:
    • FB causes partial obstruction.
    • Air passes in and out.
    • Sign: Localized wheeze.
  2. Check-Valve (Ball-Valve):
    • Air enters during inspiration (airway dilation).
    • Air cannot exit during expiration (airway collapse).
    • Result: Obstructive Emphysema (Air trapping/Hyperinflation) distal to obstruction.
  3. Stop-Valve:
    • Complete obstruction. No air enters or exits.
    • Result: Atelectasis (Collapse) of the lung segment.
  4. Ball-Valve (Reverse): Rare; air exits but cannot enter.

III. Clinical Features: The 3 Stages

Triad: Sudden onset Cough, Wheeze, Decreased Air Entry.

  1. Stage 1: Initial Event (Choking Crisis)

    • Sudden onset of violent coughing, gagging, and choking.
    • Cyanosis and stridor may occur.
    • often witnessed by parents.

  2. Stage 2: Asymptomatic Interval (The “Latent” Phase)

    • The FB lodges in a bronchus; reflexes fatigue.
    • Child appears fine.
    • Danger: Often leads to delayed diagnosis or misdiagnosis as asthma.

  3. Stage 3: Complications

    • Obstruction, erosion, or infection leads to pneumonia, lung abscess, or bronchiectasis.
    • Fever, productive cough, hemoptysis.

IV. Diagnosis

1. History (Most Important)

  • A positive history of choking is highly specific (Sensitivity >90%).
  • “A choking child is a foreign body until proven otherwise.”

2. Physical Examination

  • Classic Signs:
    • Unilateral decreased air entry.
    • Localized wheeze (monophonic).
    • Tracheal shift (away from air trapping, towards collapse).

3. Radiology (Chest X-ray)

  • Standard: PA View (Inspiration and Expiration).
  • Findings:
    • Radio-opaque FB: Visible (coins, metal) - only 10-15% of cases.
    • Radio-lucent FB (Vegetative): Indirect signs are key.
      • Obstructive Emphysema: Hyperlucency on the affected side.
      • Mediastinal Shift:
        • Inspiration: Normal or slight shift to affected side.
        • Expiration: Mediastinum shifts to the NORMAL side (Holzknecht sign) because the obstructed lung cannot deflate.
      • Atelectasis: Opacity/collapse (late sign).

V. Management

1. Emergency (If Choking/Apneic)

  • <1 year: Back blows and Chest thrusts.
  • >1 year: Heimlich Maneuver (Abdominal thrusts).
  • Unresponsive: CPR.

2. Definitive Management

Rigid Bronchoscopy is the Gold Standard for both diagnosis and removal.

  • Procedure: Under General Anesthesia (spontaneous ventilation preferred).
  • Why Rigid?
    • Better control of the airway.
    • Ability to use optical forceps for grasping.
    • Better suctioning of secretions/blood.
  • Flexible Bronchoscopy: Used primarily for diagnosis in doubtful cases or distal FBs.

3. Post-Procedure

  • Observation for laryngeal edema.
  • Antibiotics (if chemical pneumonitis or secondary infection is present).
  • Steroids (short course) for edema.

VI. Complications

  • Acute: Laryngeal edema, Hypoxic brain injury, Pneumothorax.
  • Chronic (Delayed Diagnosis):
    • Recurrent Pneumonia (same lobe).
    • Lung Abscess.
    • Bronchiectasis (irreversible damage).

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