Suspicious clinical features include: discrepancy btwn history and physical findings, prolonged delay before seeking medical attention, recurrent trauma, inappropriate response of parents to child or to medical advice, child is overly fearful or withdrawn, sharply demarcated burns in unusual areas, long bone factures in children < 3yrs, trauma in genital or perianal areas, multiple old scars or healed fractures, bizarre injuries (bites, cigarette burns, rope marks).
A smaller object that passes through the larynx usually lodges in a mainstem bronchus. Complete obstruction causes atelectasis as air is absorbed distally.
Partial obstruction of a bronchus produces hyperinflation distally through a ball-valve effect, as the airway collapses around the object during expiration and excessive air is trapped.
CXR rarely shows a radiopaque foreign body, but often demonstrates hyperinflation of the invovled lung or lobe. Expiratory films and fluoroscopy are very helpful b/c expiration exaggerates the hyperinflation and produces the mediastinal shift in the opposite direction.
If there is any suspicion of foreign body aspiration, rigid bronchoscopy is performed under general anesthesia.
Symptoms of obstruction, perforation, and bleeding are indications for immediate intervention. If the swallowed object is seen lodged in the esophagus on x-ray, there is significant risk of perforation.
If batteries are swallowed and do not advance beyond the stomach for 24 hours or remain in the same area of intestine for a week despite purgatives and enemas, their removal is indicated.