Foreign Body Aspiration

Overview

Epidemiology

• 80% of cases occur in patients < 15 years of age
• 80% of pediatric cases < 3 years of age
• Common cause of death: mortality highest in patients < 1 year of age and > 75 years of age

Etiology

Foreign bodies (FBs) aspirated vary based on age.

• Food is the most common substance in infants:
  • Nuts (35%–50% of all FBs)
  • Seeds
  • Popcorn
  • Raw vegetables (carrots, celery, etc.)
  • Hot dogs 
• Small objects are more common in older children:
  • Jewelry (30%)
  • Coins (10%)
  • Toys
  • Button batteries
  • Beads
• Adults:
  • Inorganic:
    • Nails or pins held in the mouth that are accidentally swallowed
    • Dental debris dislodged during dental procedure
    • Tracheostomy tools 
  • Organic: miscellaneous food items

Pathophysiology

• Upper airway obstruction:
  • More common in children given relative anatomical narrowing of tracheobronchial tree
  • In most pediatric cases, large food or objects are visible in the oropharynx.
• Lower airway obstruction:
  • Ball-valve effect:
    • Allows air in with inspiration
    • Prevents air exiting upon expiration
    • Results in hyperinflation of 1 or more lobes 
  • When an object is situated in the bronchus:
    • Wheezing may be unilateral.
    • Decreased breath sounds

Signs and symptoms

• Sudden-onset coughing, cyanosis, respiratory distress
• Initial choking spell followed by:
  • Cough
  • Stridor (if lodged in trachea)
  • Wheezing (if lodged in bronchus)
  • Respiratory distress
• Fever: late finding related to abscess or pneumonia
• Hypoxia: Saturation does not improve on providing supplemental oxygen.
• In 50% of cases, aspiration episode is not noticed; complications due to delayed presentations include the following:
  • Patient may have cough and fever.
  • Retained batteries can cause erosion of mucosal surfaces.
  • Lung abscesses can form around undetected foreign bodies.

Diagnosis

Most cases involve materials not visible on radiographs (e.g., food, wood, and plastic). In these cases, characteristics of the lung appearance may suggest a foreign body. Computed tomography (CT) or bronchoscopy can confirm suspicion.

• X-rays: lateral neck and chest radiographs
  • Only radiopaque objects (metal, bone, etc.) are visible.
  • Normal X-ray does not rule out FB aspiration.
  • Signs of FB invisible on X-ray: 
    • Mediastinal shift away from side of FB
    • Collapse (atelectasis) of single lobe
    • Hyperinflation of segment of lung
    • Focal pneumonia
• Bronchoscopy: Rigid bronchoscopy allows for retrieval of FB (flexible is only diagnostic). 
• CT: 
  • Used if X-ray is negative but patient is symptomatic
  • Used in cases with very low clinical suspicion as bronchoscopy achieves same diagnostic results and gives opportunity for treatment

Management

Airway obstruction requires immediate action given the high risk for asphyxia.

• Life-threatening cases with complete blockage of airway:
  • Look in oropharynx and attempt to remove visible FB with finger sweep (blind finger sweep is not recommended).
  • Back blows for children < 1 year of age
  • Heimlich maneuver for older children or adults
  • Emergent cricothyroidotomy may be required if FB is lodged above larynx and patient is in respiratory arrest.
  • During intubation, aspirated FB can be pushed further down into bronchi to prevent complete airway occlusion.
• Stable cases:
  • Objects that block airway or can lead to mucosal damage need prompt removal.
  • Bronchoscopy (rigid preferred to flexible) is the method of choice when FB is past the oropharynx.

Clinical Relevance

• Airway obstruction: partial or complete blockage of airways. Classified into upper or lower airway obstructions. Can be caused by FBs, masses, or infection. Management is based on the causes of obstruction.
• Pneumonia in children: infection of pulmonary parenchyma, diagnosed clinically with signs and symptoms of respiratory distress and inflammation. Chest X-ray may be supportive. Treatment involves antimicrobial therapy based on suspected pathogen. Typically, the patient has a good prognosis.
• Respiratory failure: inadequate oxygenation of blood or inadequate ventilation (elimination of CO₂) or both. Management involves treating the underlying cause, oxygen administration, and, if necessary, mechanical ventilation.
• Chronic bronchitis: characterized by cough for > 3 months in > 2 consecutive years. Central and peripheral airways are involved in pathophysiology of the disease.