Localizing ingested coins with a metal detector.

This study was conducted to determine the utility of metal detection in coin localization by inexperienced operators, and determine the rate of spontaneous passage of asymptomatic esophageal coins. All children who presented to the emergency department of an urban children's hospital with a suspected coin ingestion were eligible. Coin location was predicted from metal detector results, while radiographs confirmed location. Asymptomatic patients with esophageal coins were observed for spontaneous passage. Ninety-one children (ages 9 months to 17 years) were prospectively enrolled. The metal detector had a sensitivity of 98% (53/54) in coin detection and 98% (81/83) in determining coin location as esophageal. Symptoms were poor predictors of coin location. Six of eight asymptomatic patients with esophageal coins spontaneously passed their coins. These results show that metal detection is a good screening test for coin presence and to determine coin location as esophageal. Spontaneous passage of asymptomatic esophageal coins warrants further study.