OBJECTIVES: To determine the factors related to spontaneous passage of ingested coins in children.

METHODS:
Design: Retrospective study

Setting: Tertiary Government Hospital

Subjects: The records of 136 pediatric patients with a history of coin ingestion seen at the emergency room department of our institution between December  2012 and May 2014 were retrospectively reviewed. Demographic data such as age and gender of the patient were recorded, including the type of coin, location of coin in the esophagus, time of ingestion and time of spontaneous passage into the stomach (for those that passed spontaneously).

RESULTS: Spontaneous passage in 27 out of 136 pediatric patients with radiographic evidence of a round radio-opaque foreign body initially located in the esophagus eventually passed into the stomach or intestines, accounting for 20% of the total number of cases. Coin ingestion was more common in patients aged 5 to 6 years (33% of cases), with slight male predominance (58%). One peso coins were the most common type of coin ingested, however only 24% of these spontaneously passed. The rate of spontaneous passage was highest in smaller sized coins (5 and 25 centavo coin) compared to larger sized coins (5 peso). Proximally located coins, albeit more common than middle and distally located coins, were the least likely to spontaneously pass (12%). Average time interval from ingestion to passage of the coin was 12 hours.

CONCLUSION: Many factors are related to spontaneous passage of foreign bodies in the esophagus. The age of the patient, type of coin ingested, and initial location of the coin in the esophagus should be considered. Older patients, smaller sized coins, and distally located coins have the highest probability of spontaneous passage beyond the esophagus. A 12-hour observation period may be considered in patients with single esophageal coin ingestion.