Foreign Body Aspiration

Foreign body aspiration is inhalation of a foreign object into the lower respiratory tract. It is a significant cause of morbidity and, in severe cases, mortality. It occurs predominantly in young children, particularly those aged one to three years.

This age reflects oral exploration combined with immature swallowing coordination and a relatively narrow airway. Food is the commonest aspirated material in this age group, particularly nuts, seeds, and other small, hard or round foods.

Presentation and urgency vary with the location of the foreign body. Laryngeal or tracheal foreign bodies carry immediate, potentially catastrophic airway obstruction risk. A more distal, bronchial foreign body is generally less acutely dangerous, though still clinically significant.

A systematic, structured approach is needed for both immediate emergency management and definitive removal.

Pathophysiology and epidemiology

• The right main bronchus is the commonest site for a foreign body to lodge once past the larynx and trachea. Its course is somewhat straighter and more vertical than the left main bronchus.
• Foreign bodies can lodge at any level of the respiratory tract. The location directly determines the clinical presentation and any radiographic findings.
• Complete bronchial obstruction produces distal atelectasis. The affected lung segment or lobe collapses as trapped gas is gradually reabsorbed.
• Partial, ball-valve type obstruction allows air past the object during inspiration but traps it during expiration, because the airway narrows dynamically in expiration. This produces regional hyperinflation and air trapping. It is the classic, though not universally present, radiographic finding in bronchial foreign body.
• Delayed presentation is common where the initial choking or aspiration episode was unwitnessed or not recognised as significant.
• Delayed presentation is more insidious and subacute. Features include recurrent pneumonia affecting the same lung segment, or persistent cough or wheeze.
• Consider it in any child with an atypical, recurrent, or persistent respiratory presentation, particularly where symptoms are localised to a consistent lung region.

• Acute presentation, immediately after the aspiration event, is sudden coughing, choking, and gagging. There may be a brief period of stridor or respiratory distress as the foreign body transiently passes the larynx or trachea.
• Symptoms often settle as the object passes distally into a bronchus.
• Complete upper airway obstruction from a laryngeal or tracheal foreign body is a genuine, life threatening emergency. It needs immediate intervention.
• Once lodged within a bronchus, the classic clinical triad is cough, unilateral wheeze, and reduced or absent breath sounds over the affected lung region.
• The complete triad is present in only a proportion of confirmed cases. Its absence should not exclude the diagnosis where there is a compatible history or clinical suspicion.
• Delayed or subacute presentation may be recurrent or persistent respiratory symptoms. These include chronic cough, recurrent wheeze, or recurrent pneumonia consistently affecting the same lung segment or lobe.
• Wheeze is sometimes misdiagnosed as asthma, particularly where it is unilateral or atypical for asthma.
• Consider a retained foreign body in any child with this pattern of recurrent, localised respiratory symptoms.
• A witnessed choking episode, or access to a relevant small object or food item just before symptom onset, is valuable supportive history.
• Such episodes are not infrequently unwitnessed or not initially recognised as significant by carers. The absence of a witnessed or recalled choking episode should not exclude the diagnosis where the presentation is otherwise compatible.

• Chest radiography, with both inspiratory and expiratory views where the child's status and cooperation permit.
• It may show the foreign body directly where radio-opaque. The great majority of aspirated foreign bodies, including food items, are radiolucent and not directly visible on standard radiography.
• It may show indirect signs of regional hyperinflation and air trapping. These are more apparent on the expiratory view, where the obstructed lung segment fails to show the normal volume loss seen in surrounding lung.
• With complete obstruction, it may show atelectasis of the affected lung segment.
• A normal chest radiograph does not exclude the diagnosis. Findings are frequently subtle or absent, particularly early after aspiration or where the foreign body causes only partial, non-obstructive narrowing.
• Bronchoscopy is the diagnostic and therapeutic reference standard where clinical suspicion remains significant despite normal or equivocal imaging.
• Computed tomography of the chest may be considered in diagnostic uncertainty, particularly for delayed or atypical presentations. It is more sensitive than plain radiography for the foreign body and any secondary changes. Direct bronchoscopy remains the definitive approach where suspicion is significant.
• Rigid bronchoscopy is both the diagnostic reference standard and the primary therapeutic approach for confirmed or strongly suspected foreign body aspiration. Perform it under general anaesthesia by an experienced operator, with airway management support immediately available.
• It allows direct visualisation and, in the great majority of cases, successful, definitive removal in the same procedure.

• Complete upper airway obstruction from a laryngeal or tracheal foreign body is an immediate, life threatening emergency. The time window before hypoxic injury or death is extremely limited.
• Start standard basic life support foreign body airway obstruction management immediately: back blows and chest thrusts in infants, or abdominal thrusts in older children, following age-appropriate resuscitation guidelines.
• If basic airway clearance fails and the child develops complete, unrelieved obstruction with loss of consciousness, use direct laryngoscopy and attempt visualisation and removal with Magill forceps.
• If that fails and the situation is immediately life threatening, emergency surgical airway access is the necessary, definitive intervention. This is cricothyroidotomy, adapted to the age and size of the child.
• The more common scenario is a stable child with a suspected or confirmed bronchial foreign body and no complete, immediately life threatening obstruction. Arrange urgent, though not necessarily immediate, transfer to a centre with paediatric anaesthesia and bronchoscopy capability. Monitor closely during transfer and preparation.
• Avoid unnecessary, potentially destabilising interventions and excessive handling. These might dislodge a partially obstructing foreign body into a position causing complete airway obstruction.
• Rigid bronchoscopy under general anaesthesia is the definitive management for confirmed bronchial foreign body. An experienced paediatric otolaryngology or respiratory team should perform it.
• Anaesthetic technique is an important consideration. Generally maintain spontaneous ventilation where feasible. Positive pressure ventilation theoretically risks converting a partial, ball-valve obstruction into complete obstruction by forcing the foreign body further distally.
• After removal, repeat bronchoscopic assessment confirms complete removal. It also assesses and addresses any mucosal injury or secondary infection.
• Give antibiotic therapy where there is evidence of associated pneumonia or significant mucosal infection. Follow up chest radiography confirms resolution of any associated atelectasis or other abnormality.
• Prevention is an important, evidence based strategy for this largely preventable condition. Educate parents and carers on age-appropriate food choices: avoid whole nuts, and cut round foods, including grapes and hot dogs, into appropriately sized pieces for young children.
• Supervise young children carefully during eating and play. Keep small, easily aspirated toys or objects out of their reach.