• Clinical science

Foreign body aspiration (FBA)

Abstract

Foreign body aspiration (FBA) is a potentially life-threatening emergency that most commonly occurs in children aged 1–3 years. FBA typically manifests with sudden onset of coughing and choking, followed by stridor and dyspnea. Obstruction of the larynx or trachea is a potentially life-threatening situation that causes severe respiratory distress, cyanosis, and suffocation. Most commonly, the foreign body (FB) becomes lodged in the main and intermediate bronchi; approx. 60% of FB are located in the right main bronchus due to the more vertical orientation compared to the left main bronchus. Partially obstructed airways result in the formation of a ball-valve obstruction, in which air trapping occurs in the lung segments distal to the obstruction. This focal hyperinflation of the lung segments are detectable on x-ray as hyperlucency and reduced pulmonary marking. Complete obstruction results in atelectasis distal to the FB. The FB should be removed via bronchoscopy as soon as possible. If an FBA remains undetected, it may result in chronic cough and recurrent pulmonary infections.

Epidemiology

  • 80% of cases occur in children < 3 years
  • Peak incidence: 1–2 years

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

  • Aspiration of a FB (e.g., nuts, raisins, coins, pieces of toys)
  • Often occurs when children speak, laugh, or play while chewing; toddlers are also prone to examining objects with their mouth, so that a sudden inspiration can result in aspiration.

References:[2]

Pathophysiology

  • Aspiration of a FBairway obstruction
    • Complete obstruction → collapse of the respiratory structures distal to the obstruction (e.g., atelectasis) .
    • Partial obstruction: formation of a ball-valve obstruction with air trappingbuild-up of pressure distal to the obstruction
  • Localization
    • Upper airway obstruction: a minority of FB are lodged in the larynx or trachea
    • Bronchi: the right main bronchus is more often affected than the left main bronchus
      • Aspirated particles are most likely to become lodged at the junction of the right inferior and right middle bronchi → right lower and middle lobe aspiration pneumonia
      • Upper right lobe affected in bedridden patients, particularly while lying on their right side.
      • In children, the two main bronchi are affected with more similar frequency than in adults; however, there still a slight right-sided predominance.
      • Less severe than upper airway obstructions

References:[2][1][3][4]

Clinical features

  • Immediate symptoms
    • Choking and coughing
    • Dyspnea
    • Hoarseness and inability to speak
    • Respiratory distress, cyanosis, altered mental state
  • Physical exam
    • Diminished breath sounds on the affected side
    • Stridor, wheezing
      • On inspiration: indicates laryngotracheal localization
      • On expiration: indicates bronchial localization
    • Hyper-resonance on the affected side in partial obstruction
  • Late symptoms: days or weeks later if the initial aspiration and choking episode is not witnessed

References:[1]

Diagnostics

Scenario Approach
Life-threatening FBA (respiratory distress)
  1. Immediate intervention (no imaging required!)
Stable patients with suspected FBA
  1. Physical exam
  2. Chest x-ray or CT (if x-ray is inconclusive)
  3. Bronchoscopy
  • Chest x-ray
    • Focal hyperlucency and reduced pulmonary markings of the affected lung
    • Atelectasis
    • 60% of FB are located in the right main bronchus due to the more vertical orientation compared to the left main bronchus
    • More cranial obstructions are hard to identify on x-ray. The lateral view allows for better visualization in such cases
  • CT (nearly 100% sensitivity): if x-ray is inconclusive
  • Bronchoscopy: if imaging is inconclusive but there is a high clinical suspicion of FBA

If there is a high suspicion of FB aspiration, bronchoscopy or CT should be performed even if the chest x-ray is inconclusive!
References:[2][1]

Differential diagnoses

The differential diagnoses listed here are not exhaustive.

Treatment

Life-threatening FBA

  • In alert patients, encourage coughing to dislodge FB
  • Heimlich maneuver: if the patient is unable to speak or cry
    • Perform five quick abdominal thrusts; this increases intrapulmonary pressure and may dislodge the object
    • In infants: perform five chest compressions, holding the child in supine position with his/her head tilted back, until the infant begins coughing effectively or the foreign body is expectorated.
  • Intubation: Attempt to mobilize FB via endotracheal tube
  • Emergency tracheotomy may be required

Removing the foreign body

  • Bronchoscopy (gold standard)
  • In rare cases, surgical removal may be necessary

References:[5][2][1][6]

Complications

References:[5]

We list the most important complications. The selection is not exhaustive.

last updated 09/07/2018
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