Foreign Body Aspiration

Updated: Dec 31, 2015
  • Author: Martin E Warshawsky, MD, FACP, FCCP; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Overview

Background

Foreign body aspiration can be a life-threatening emergency. An aspirated solid or semisolid object may lodge in the larynx or trachea. If the object is large enough to cause nearly complete obstruction of the airway, asphyxia may rapidly cause death. Lesser degrees of obstruction or passage of the obstructive object beyond the carina can result in less severe signs and symptoms.

Chronic debilitating symptoms with recurrent infections might occur with delayed extraction, or the patient may remain asymptomatic. The actual aspiration event can usually be identified, although it is often not immediately appreciated. The aspirated object might even escape detection. Most often, the aspirated object is food, but a broad spectrum of aspirated items has been documented over the years. Commonly retrieved objects include seeds, nuts, bone fragments, nails, small toys, coins, pins, medical instrument fragments, and dental appliances.

Geographic differences in the spectrum of objects commonly found in a particular environment and variations in dietary and eating habits affect the relative frequency with which various objects are aspirated.

The Medscape Drugs & Diseases article Airway Foreign Body Imaging may be helpful.

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Pathophysiology

Near-total obstruction of the larynx or trachea can cause immediate asphyxia and death. Should the object pass beyond the carina, its location would depend on the patient's age and physical position at the time of the aspiration. Because the angles made by the mainstem bronchi with the trachea are identical until age 15 years, foreign bodies are found on either side with equal frequency in persons in this age group. [1] With normal growth and development, the adult right and left mainstem bronchi diverge from the trachea with very different angles, with the right mainstem bronchus being more acute and therefore making a relatively straight path from larynx to bronchus. Objects that descend beyond the trachea are more often found in the right endobronchial tree than in the left.

In the series reported by Debeljak et al, [2] 42 foreign bodies were in the right endobronchial tree, 20 were in the left, and 1 was in the trachea. Once aspirated, objects may subsequently change position or migrate distally, particularly after unsuccessful attempts to remove the object or if the object fragments. The object itself might cause obstruction. Vegetable material may swell over hours or days, worsening the obstruction. Cough, wheeze, stridor, dyspnea, cyanosis, and even asphyxia might ensue. Organic foreign bodies, such as oily nuts (commonly peanuts), induce inflammation and edema.

Local inflammation, edema, cellular infiltration, ulceration, and granulation tissue formation may contribute to airway obstruction while making bronchoscopic identification and removal of the object more difficult. [3] The airway becomes more likely to bleed with manipulation; the object is more likely to be obscured and becomes more difficult to dislodge. Mediastinitis or tracheoesophageal fistulas may result. Distal to the obstruction, air trapping may occur, leading to local emphysema, atelectasis, hypoxic vasoconstriction, postobstructive pneumonia, and the possibility of volume loss, necrotizing pneumonia or abscess, suppurative pneumonia, or bronchiectasis.

Bronchoscopically, the object may appear as a tumor. Even if the object is removed, the inflammatory changes may not be completely reversible. Some investigators believe scar carcinoma may develop over time. The likelihood of complications increases after 24-48 hours, making expeditious removal of the foreign body imperative.

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Epidemiology

Frequency

International

Most of the literature relates to statistics, diagnosis, and treatment in children younger than 16 years. [4] Literature on foreign body aspiration in adults is limited. Local environments have an important influence on the types of objects aspirated, location in the tracheobronchial tree, and prognosis.

Geographic differences in the spectrum of objects commonly found in a particular environment and variations in dietary and eating habits affect the relative frequency with which various objects are aspirated. The heterogeneity of the populations studied, materials in the environment, and the availability of medical technology influence the reported incidence and prognosis.

Many aspirated foreign bodies are unexpectedly discovered, go undetected, or are misdiagnosed. The often-fatal syndrome of acute asphyxiation from upper airway obstruction associated with eating, known as the café coronary, [5] and aspiration of gastric contents are usually not considered with other foreign body aspiration syndromes. For these reasons, the true incidence and prevalence of foreign body aspiration is unknown.

Mortality/Morbidity

According to the National Safety Council, choking remained the fourth leading cause of unintentional injury death in the United States as of 2004. In 2006, a total of 4,100 deaths (1.4 deaths per 100,000 population) from unintentional ingestion or inhalation of food or other objects resulting in airway obstruction was reported. [6] The incidence rate was 0.5 deaths per 100,000 population aged 0-4 years. It was lower for adolescents and young adults. The incidence rate then increased steadily with age beginning in the sixth decade (2.6 deaths per 100,000 population aged 65-75 y) and rose rapidly after age 70 years (13.6 deaths per 100,000 population older than 75 y).

The overall risk of death from the café coronary is estimated to be 0.66 deaths per 100,000 people. Even if the patient does not die, symptoms often develop immediately. Morbidity increases if extraction of the object is delayed beyond 24 hours.

Sex

The male-to-female ratio is 2:1, depending on the study.

Age

Children, especially those aged 1-3 years, are at risk for foreign body aspiration because of their tendency to put everything in their mouths and because of the way they chew. Young children chew their food incompletely with incisors before their molars erupt. Objects or fragments may be propelled posteriorly, triggering a reflex inhalation.

Adults who (1) undergo oropharyngeal procedures, (2) have various oral appliances, (3) become intoxicated, (4) receive sedatives, or (5) may have neurological or psychiatric disorders are at increased risk of aspirating foreign bodies.

Because young children and older persons with neurological, cognitive, or psychiatric disorders might not be able to provide their history, diagnosis may be delayed. In Limper and Prakash's 1990 study, [7] the median age for adults (ie, patients >16 y) with foreign body aspirations was 60 years, with an age range of 18-88 years. Numerous studies concur that children younger than 16 years account for most cases of foreign body aspiration.

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