12.3 Foreign Body Aspiration & Other Airway Disorders

Foreign Body Aspiration

Foreign body (FB) aspiration is a leading cause of accidental death in children under 3 years old and should be considered in any young child with sudden-onset respiratory symptoms. The peak age is 1-3 years, reflecting a combination of oral exploratory behavior, immature molars (poor grinding of food), and a tendency to run or play while eating. The most commonly aspirated objects are food items -- nuts, seeds (especially peanuts and sunflower/watermelon seeds), and popcorn -- followed by small toy parts, coins, and balloon fragments.

Classic Presentation

The classic triad of foreign body aspiration is: (1) a witnessed or reported choking/coughing episode, (2) unilateral wheeze, and (3) decreased or asymmetric breath sounds on the affected side. Because the right main bronchus is wider, shorter, and more vertically aligned than the left, aspirated objects lodge in the right mainstem bronchus more often than the left.

Presentation depends on timing:

• Immediate: choking, coughing, gagging, stridor (if the object lodges in the larynx or trachea) or wheeze (if it lodges more distally in a bronchus); complete obstruction causes sudden respiratory distress, inability to speak or cry, and cyanosis -- a true emergency.
• Delayed or missed: if the initial choking episode is not witnessed or is forgotten, the child may present days to weeks later with a persistent unexplained cough, recurrent or non-resolving pneumonia in the same lung segment, localized wheeze misdiagnosed as asthma, or hemoptysis. A history of a choking episode is often absent in these delayed presentations, so a high index of suspicion is required whenever a young child has unilateral or fixed radiographic findings.

Radiographic Findings

Most aspirated foreign bodies (especially food items) are radiolucent and will NOT be directly visible on plain radiograph, so diagnosis relies on indirect signs of air trapping and asymmetry rather than seeing the object itself:

• Obstructive (ball-valve) air trapping and hyperinflation on the affected side, best seen on an expiratory film (the normal lung empties while the obstructed side remains hyperinflated) or, in a young child who cannot cooperate with inspiratory/expiratory views, on a lateral decubitus film (the dependent normal lung should deflate; failure to deflate on the affected side when it is dependent suggests air trapping)
• Mediastinal shift away from the obstructed side during expiration
• Atelectasis or consolidation distal to a completely obstructing object
• A normal chest radiograph does NOT exclude foreign body aspiration, particularly soon after aspiration or with a radiolucent object -- clinical suspicion should still prompt bronchoscopy
• CT chest may be used when the diagnosis remains uncertain after plain films, though it should not delay bronchoscopy in a clinically clear case

Management

• For a witnessed acute complete airway obstruction with an ineffective cough or cyanosis, first aid follows basic life support choking protocols: back blows and chest thrusts in infants under 1 year; the Heimlich maneuver (abdominal thrusts) in children over 1 year.
• Once the airway is stabilized, or in a stable child with a suspected retained foreign body, rigid bronchoscopy under general anesthesia is both diagnostic and therapeutic -- it is the gold-standard procedure for foreign body removal in children, allowing direct visualization and use of retrieval instruments while maintaining ventilation through the bronchoscope. Flexible bronchoscopy is primarily diagnostic and is not typically used for retrieval in young children.
• Do NOT perform blind finger sweeps in infants or young children, as this can push the object further into the airway.
• Delayed removal risks granulation tissue formation, post-obstructive pneumonia, and bronchiectasis in the affected segment.

Other Pediatric Airway Disorders

Laryngomalacia

Laryngomalacia is the most common cause of chronic stridor in infants and the most common congenital laryngeal anomaly. It results from floppy, immature supraglottic cartilage that collapses inward during inspiration.

• Presentation: high-pitched inspiratory stridor that begins in the first weeks of life, is worse when supine, feeding, crying, or agitated, and improves in the prone position; typically peaks around 4-8 months of age.
• Diagnosis: flexible fiberoptic laryngoscopy, performed awake, showing a characteristic omega (Ω)-shaped epiglottis, short aryepiglottic folds, and prolapse of redundant supraglottic tissue into the airway during inspiration.
• Course: the majority of cases are mild and self-limited, resolving spontaneously by 18-24 months as the cartilage matures; reassurance and observation are sufficient.
• Red flags requiring intervention (supraglottoplasty -- surgical division of the aryepiglottic folds): failure to thrive, feeding difficulty with aspiration, significant apnea or cyanotic episodes, or severe obstructive symptoms.

Other Causes of Stridor/Airway Obstruction to Recognize

Distinguish inspiratory stridor (extrathoracic obstruction, e.g., laryngomalacia, croup) from expiratory wheeze/stridor (intrathoracic obstruction, e.g., tracheomalacia, bronchiolitis, asthma) -- a simple physiologic rule that resolves many "which diagnosis" questions on the written paper.