Choking is defined as the interruption of respiration due to the internal obstruction of the airway. Aspiration is defined as the penetration of foreign material into the trachea, beyond the vocal cords. Airway obstruction relating to the presence of a foreign body, however, may be intra-luminal (foreign body within the airway) or extra-luminal (foreign body within the esophagus causing airway compression). Children suffering from these conditions may present with cardiorespiratory arrest, impending respiratory arrest, a stable but symptomatic status, or with sequelae of a previous choking or aspiration event. These patients often present to hospitalists in the emergency department or inpatient setting and therefore knowledge of the full range of the presentations is important.

The death rate from unintentional suffocation in children aged 0 to 4 years, which includes aspiration or ingestion of foods, is estimated at 3 per 100,000 but declines by nearly a factor of 10, to 0.36 per 100,000 for children aged 5 to 9 years.¹ Data from Australia support a similar incidence and trend, with rates of fatal injury being 10 times greater in the first years of life as compared to the second decade of life.² In the United States, choking on food or other foreign objects is the direct cause of death of several hundred children each year.^3-6 Choking therefore remains a major cause of preventable death and morbidity in the United States, although efforts by the federal government and public health community have made some progress in decreasing its occurrence.

Choking and aspiration involve the interaction between an object and the airway in such a way as to prevent breathing from being fully effective. It may be a reversible event if airway defenses are able to expel the foreign material and clear the airway, or it may result in symptomatic airway obstruction.

If severe enough, airway obstruction will lead to oxygen deprivation and death if not rapidly and effectively addressed. If partial obstruction of the airway results, a subacute process may result in infection, inflammation, and lung injury distal to the lodged object. Another mechanism of choking involves the impaction of foreign material in the esophagus with resultant airway compression.

Choking results from a complex interaction between the victim, the environment, and the object at hand. Young children, with their incompletely developed dentition and oral skills, smaller airways, immature swallowing mechanisms, and their lack of experience and cognition are at highest risk of choking. Also, they tend to explore the world by bringing objects to their mouths. Children with developmental delay, hypotonia, dysphagia, or anatomic abnormalities retain this increased risk into their later years. Older siblings or playmates may also share inappropriate foods or toys with younger siblings. Environmental factors such as a lack of supervision, access to an object, and circumstances surrounding meals and snacks are important. In many published reports, males have a higher risk of choking than females.^3-8

Common choking hazards have been well studied and characterized. Small, round, smooth, and slippery objects are most commonly associated with choking in children. Objects of any size with a pliable texture that can conform to the shape of the airway or adhere to the airway mucosa and form a plug also represent a hazard. If a plug does form and cannot be dislodged in a timely fashion, due to either a lack of adequate response by the child or a supervising adult or due to the characteristics of the object, death will ultimately ensue from asphyxiation. Food and toys are the most common objects involved with accidental choking and foreign body aspiration, and are listed in Table 145-1, whereas less commonly reported culprits include sand⁹ and gummi bears.¹⁰

A description of the choking event and the circumstances should be obtained, as well as identification of any predisposing factors or previous choking episodes. One symptom commonly associated with foreign body aspiration is “penetration syndrome,” defined as the sudden onset of choking and intractable cough with or without vomiting.^11,12 However, the clinician may not always be able to elicit this information or it may not be available at the time of initial evaluation. Patients with acute complete airway obstruction at or above the level of the carina are immediately symptomatic with aphonia, lack of cough, cyanosis, or agitation that can progress to obtundation or cardiopulmonary arrest. Partial airway obstruction may present with a range of symptoms depending on the degree or level of the obstruction. When the blockage occurs in the extrathoracic airway, findings on physical examination may include stridor, cough, or dysphonia. With obstruction of the intrathoracic airway, cough, localized wheezing, or asymmetric breath sounds may be present. Evidence of increased respiratory effort, such as retractions, nasal flaring, or use of accessory muscles, will be more prominent with more complete obstruction or with involvement of a more proximal airway. In some cases, the physical examination may be normal, especially with more distal airway involvement. Progression from partial airway obstruction to complete obstruction can occur, as can cardiorespiratory failure due to severe or prolonged partial obstruction. Conversely, complete airway obstruction may transition to partial airway obstruction, with subsequent improvement in symptoms. These children may be particularly unstable, and deterioration back to complete airway obstruction is a significant concern. Esophageal foreign bodies may present with drooling, odynophagia, gagging, retching, and respiratory distress due to impingement of the esophagus on the membranous posterior wall of the trachea.

In the subacute or chronic setting, patients may present with chronic cough and fever as post-obstructive infection develops in the lung parenchyma distal to the aspirated object. Some foreign objects, especially plant and food material, can evoke a particularly intense inflammatory reaction at the site of the foreign body (foreign body reaction).

EVALUATION

A patient presenting with a first episode of wheezing should have a chest radiograph to rule out a foreign body or another unexpected abnormality. Although an unanticipated finding is not common and has been discussed previously as not always necessary, chest radiography is advised.^13,14 Children with localized, non-migratory, or monophonic wheezing as well as those with a history of a choking spell, suspected foreign body ingestion, or history of a previous aspiration event should be imaged as well.

If a radio-opaque foreign body (Figure 145-1) is not identified on initial anteroposterior and lateral chest radiographs, additional views may be warranted. Inspiratory and expiratory anteroposterior chest radiographs or bilateral decubitus (Figure 145-2) chest views may indirectly indicate the presence of a radiolucent foreign body. In the acute setting, when a foreign body obstructs a bronchus or bronchiole, air trapping can occur distal to the airway obstruction. During inspiration, the intrathoracic airways are relatively expanded which allows aeration around an obstructing foreign body. During expiration, there is narrowing of these airways, which can impede flow out of the partially obstructed lung segment resulting in localized air trapping (“ball-valve” effect). Children with partial airway obstruction distal to the carina will demonstrate inflation throughout both lung fields on an inspiratory chest radiograph. However, on exhalation, hyperinflation or hyperlucency in the lung segment beyond the site of obstruction can be seen.