Older infants and toddlers constitute the vast majority of patients with foreign body aspiration. Darrow and Holinger⁸ reviewed multiple case series and found that children <5 years of age account for approximately 84% of cases and children <3 years account for 73%. The high incidence in this age group reflects the tendency of children to explore the world using their mouths. In addition, these children have not developed a full posterior dentition and may have immature neuromuscular mechanisms for swallowing and airway protection. Moreover, many youngsters are allowed to talk, run, or play with food or other objects in their mouths. For uncertain reasons, boys aspirate foreign bodies more frequently than girls by a ratio of approximately 2:1. In adults, other factors play a role in foreign body aspiration, such as neurologic dysfunction, dental trauma, and aspiration of larger than normal pieces of food, usually associated with alcohol consumption.

Although adults most commonly aspirate bones from fish, birds, or small mammals, children usually aspirate vegetable matter. Darrow and Holinger⁸ found that nuts, particularly peanuts, account for approximately 34% of cases of foreign bodies found in the pediatric airway. Even nut fragments found in crunchy peanut butter have been aspirated. Other commonly aspirated types of vegetable matter include pieces of raw carrot, apple, dried beans, popcorn, and sunflower, watermelon, or pumpkin seeds. Darrow and Holinger⁸ found that the most commonly aspirated inorganic objects in school-aged children include tacks, nails, pencil erasers, pins, plastic beads, and even marbles.

The spectrum of airway foreign bodies varies from country to country, depending on the diet and customs of the population. For example, Mu and colleagues²³ reported that in mainland China, nearly 95% of aspirated foreign bodies in children were organic. In contrast, more industrialized countries have a greater incidence of aspiration of plastic foreign bodies, because plastic parts are used frequently by the toy industry. Other reported examples of the cultural influence on these accidents include aspiration of Mardi Gras beads, pieces of crab shell, holiday decorations and gifts, and straight pins by Middle Eastern women and girls, who hold the pins between their lips while securing their head scarves. Fortunately, ingestion of safety pins
has become rare since the advent of disposable diapers. Rarely, medical therapy itself may be responsible. Aspiration of pills, a thermometer fragment, and an object within a metered-dose inhaler has been reported.

Three stages of symptoms result from the aspiration of an object into the airway:

The current medical practice of treating an asthmatic or “croupy” child with antibiotics or corticosteroids may obscure signs and symptoms that normally would be expected with a retained foreign object. Clearing of symptoms with these agents cannot always be assumed to be diagnostic of a specific disease process. The fact that a wheeze disappears or a pneumonic process temporarily clears may merely mean that the patient’s reaction to a foreign body has been controlled temporarily. The recurrence of “asthma” after tapering of therapy should heighten a physician’s suspicion of an aspirated foreign body.

A positive history must never be ignored. A negative history may be misleading. Choking or coughing episodes accompanied by wheezing are highly suggestive of foreign body aspiration. The literature reveals that diagnosis is delayed >24 hours in 50% of cases, as noted by Wiseman,³³ and more than 1 week in 15% of cases, as reported by Reilly and colleagues.²⁷ Disregarding a child’s story because of age or lack of symptoms may cause a delay in diagnosis, which may make removal more difficult and complicated. As Wetmore³¹ stated, once an aspirated foreign body is suspected, the burden of proof is on the bron- choscopist. Furthermore, Mantor and colleagues²¹ have suggested that “some negative bronchoscopies are necessary in order to prevent the morbidity that occurs from a missed foreign body aspiration.”

Inspiratory and expiratory posteroanterior and lateral chest radiography is standard when foreign body aspiration is suspected. If the foreign body is radiopaque, a film is taken in the greatest diameter of the object for accurate localization before endoscopy. More than 90% of foreign bodies, however, are radiolucent, as reported by Vane and colleagues.³¹ This percentage is likely to increase as more polyethylenes are used to make toys.

Jackson and Jackson¹⁹ described the pathophysiology behind the radiographic diagnosis of radiolucent bronchial foreign bodies. Initially, the object creates a bypass valve, which still allows ingress and egress of air. At this stage, radiography results are normal. As edema of the surrounding bronchial wall develops, a check valve is created. On inspiration, the bronchus dilates and permits ingress of air. However, on expiration, the bronchus constricts, and contact of the edematous bronchus with the foreign body blocks the egress of air. Thus, air trapping (obstructive emphysema) results. Radiographically, when a check valve is created, the inspiratory film is normal, whereas the expiratory film shows hyperinflation of the affected lung and shift of the
mediastinum to the opposite side (Fig. 76-1). If inspiratory and expiratory films are not possible because a child is tachypneic or uncooperative, lateral decubitus chest films or fluoroscopy may also identify air trapping. Eventually, when enough edema develops to block both ingress and egress of air, a stop valve is created. Obstructive atelectasis is seen radiographically. This late complication usually takes days or weeks to develop.

Although reports vary, Black and colleagues² found that inspiratory and expiratory chest radiography was diagnostic in 83% of 440 children with tracheobronchial foreign bodies. In cases of suspected tracheal foreign bodies, posteroanterior and lateral soft tissue neck films (high-kilovoltage airway films) are the radiographic tests of choice. As Esclamado and Richardson⁹ reported, airway films are abnormal in 92% of children with tracheal foreign bodies, whereas chest radiography is abnormal in only 58%. Pneumomediastinum is a rare but highly diagnostic finding. It was reported by Burton and colleagues⁶ in 7% of patients with tracheobronchial foreign bodies. When a radiolucent foreign object’s aspiration is suspected and the airway or chest radiography is negative, one may take a radiograph of a duplicate object if available. If the object appears to be radiopaque, then the absence of finding on the radiograph is reassuring.

In rare cases, when a radiolucent foreign object is lodged too far in the lung periphery for endoscopic management, it may be precisely localized by bronchography, computed tomography, or in some cases magnetic resonance imaging. Imaizumi and colleagues¹⁵ noted that because of peanuts’ high lipid content, peanut fragments appear as high-intensity signals on T1-weighted images. Such information would confirm the diagnosis and would assist in localization if thoracotomy and segmentectomy were to become necessary.

A bronchial foreign body usually does not constitute an acute emergency unless there is complete obstruction of one main bronchus, causing inadequate oxygenation. Supraglottic, glottic, and tracheal foreign bodies are more likely to cause acute emergent situations, with severe respiratory distress. In general, the treatment of choice is reasonably prompt endoscopic removal under conditions of maximal safety and minimal trauma. Too often, foreign bodies are considered emergencies, leading to hasty, inadequate preoperative planning and poorly prepared, improper attempts at removal. Most patients with foreign bodies who have come to the endoscopic surgeon have already passed the acute phase. When no urgent danger to the patient’s life exists, the problem should be approached with complete and thoughtful consideration of the physiologic and mechanical factors involved.

The endoscopic removal can be scheduled once trained personnel are available, instruments have been checked, and techniques have been tested. However, untoward delay of bronchoscopic removal is potentially harmful because the foreign body may become dislodged from the bronchus and impacted in the larynx, causing asphyxiation. Therefore endoscopy is deferred only until preoperative studies have been obtained and the patient has been prepared for surgery by adequate hydration and emptying of the stomach. Foreign bodies in the larynx or tracheobronchial tree are usually removed on the same day the diagnosis is considered.

Two situations exist, however, in which an airway foreign body does constitute an acute emergency: actual and potential airway obstruction.