Inhaled Foreign Body

Epidemiology

Airway foreign bodies (AFB) occur mostly in young children — 80% under age 3, peak incidence 1–2 years — reflecting oral fixation at that age, increasing mobility, incomplete molar development, a superiorly-placed larynx and an immature swallow. Most aspirated foreign bodies (>80%) lodge in the bronchial tree, most often the right main bronchus (wider lumen, more vertical orientation). Younger children more often aspirate food/organic material; older children more often inhale non-food objects.

Presentation — the three-phase pattern

1. Impaction phase: acute coughing, choking, stridor, respiratory distress, possible cyanosis.
2. Asymptomatic (latent) phase: the foreign body settles in a stationary position and airway reflexes attenuate over time — the child appears well. Close to 50% of children with a confirmed AFB present entirely asymptomatically at this stage.
3. Chronic complications phase: recurrent pneumonia, chronic cough, unilateral/localised wheeze, or an asthma-mimicking presentation. Delayed diagnosis can progress to bronchiectasis and permanent lung damage.

By the time a child reaches general practice, they are commonly in phase 2 or 3. >90% will have a history of aspiration or choking somewhere in the story — history is the single most important diagnostic tool, and a detailed history should be taken for any suspected case or unexplained chronic respiratory symptoms.

Clinical clues

• Consider AFB with localised/unilateral wheeze, or wheeze not responding to bronchodilators.
• Examination findings are often normal — vital sign changes are rare. Findings when present: cough, unilateral wheeze, reduced breath sounds, or prolonged expiratory phase on the affected side.
• A normal examination does not exclude AFB and should not delay referral if the history is suggestive.

Investigations

• Chest X-ray (frontal + lateral, ideally inspiratory/expiratory phases) is first-line, but as many as 25% of bronchoscopy-confirmed AFB have a normal CXR — a normal film does not rule it out.
• Radiopaque foreign bodies are easily seen but uncommon (~11% of cases); most are organic and radiolucent. Look for indirect signs: unilateral hyperinflation, air-trapping, atelectasis, or infiltration.

Referral and management

Any child with a suspected AFB should be promptly referred to a tertiary otolaryngology/ENT service — clinical suspicion alone warrants airway examination under anaesthesia, regardless of normal examination or imaging. Flexible bronchoscopy is generally performed first (less traumatic, allows distal airway assessment) unless acute respiratory compromise is present, in which case rigid bronchoscopy is used to secure the airway. Complications of airway endoscopy are uncommon (1–8%); most children are discharged within 24 hours.

Acute choking — first aid (conscious child)

For a witnessed acute choking episode (per the Australian Resuscitation Council algorithm):

1. Up to 5 back blows (heel of palm, between the shoulder blades).
2. If unresolved, up to 5 chest thrusts (same location/technique as chest compressions).
3. Alternate back blows and chest thrusts until emergency services arrive or the obstruction clears.
4. If the child becomes unresponsive: an oral sweep to clear visible material from the oropharynx, then commence CPR.

Prevention — GP’s role in education

GPs are well placed to counsel parents/carers of young children (the American Academy of Pediatrics recommends this from age >6 months):

• Withhold classically high-risk foods until age-appropriate — the Royal Children’s Hospital Melbourne recommends avoiding popcorn, hard lollies, raw carrot and whole apple pieces before 15 months, and nuts/nut-containing food before age 4 (smooth nut butter/paste is a safer way to introduce nut protein for allergy-prevention purposes).
• Encourage children to sit quietly while eating — avoid combining eating with walking, talking, or running.
• For children <2 years, offer one piece of food at a time, cut into pieces large enough to encourage chewing rather than swallowing whole.
• Keep small toys/objects (Australian consumer-safety standards restrict toys intended for children <36 months, but other household small parts remain a risk) out of reach of young children.