Chapter 25 Foreign Body Aspiration
PATHOPHYSIOLOGY
Foreign body aspiration refers to the lodgment of an object or substance in the airway. The foreign body tends to lodge most often in the cricopharyngeal area because of the strong propulsive pharyngeal muscles that move it to this location. Obstruction may be partial or complete. Complete airway obstruction usually occurs in the upper airway and is life threatening. Most objects aspirated by children are small enough to pass through the larynx and trachea and lodge in either of the main bronchi. Examples of items may be poorly chewed hot dog pieces, peanuts, small toys, coins, or disk (button cell) batteries. The right main bronchus is a more common site because it is larger, receives greater airflow, and has a straighter line of entry than the left bronchus. The mechanisms of airway obstruction depend on the site of obstruction and whether the foreign body is partially or completely obstructing an airway. Atelectasis occurs distal to the area where air can no longer enter. Air trapping or hyperinflation occurs when air is inhaled but can be only partially exhaled.
In many cases, foreign bodies are spontaneously expelled from the tracheobronchial tree, and symptoms that persist are from residual irritation and bronchial edema. When foreign body aspiration is diagnosed quickly and the object or substance is removed in a prompt manner, the condition follows a benign course. Aspiration of foreign bodies containing saturated fats, such as peanuts, is more problematic because of the resulting irritation and inflammation of mucosal tissue. The longer a foreign body remains lodged in place, the more complications can develop, related to increasing edema, inflammation, and threat of infection.
INCIDENCE
1. Foreign body aspiration most commonly occurs in children 9 months to 5 years of age.
2. Foreign body aspiration is the leading cause of accidental death in children younger than 1 year of age.
3. Peanuts and other nuts account for about half of all aspirated foreign bodies; vegetable pieces, seeds, and raisins are also common culprits.
4. Large objects such as hot dog pieces, grapes, balloon fragments, and popcorn may obstruct the glottic inlet and lead to respiratory arrest.
CLINICAL MANIFESTATIONS
Clinical manifestations vary according to the site at which the foreign body lodges and the degree of obstruction that occurs.
