Many toys and electronics are powered by small disc batteries. These batteries are often accidentally swallowed by small children, and sometimes adults. Every year in the United States, more than 3,500 people of all ages swallow these miniature disc or “button batteries”. A study of 2,382 cases of battery ingestions reported to a national registry showed that 44.6% of the batteries were obtained from hearing aids. In 32.8% of these cases, the battery was removed from the child’s own hearing aid. Occasionally, adults swallow disc batteries as a result of putting them in their mouths while changing batteries or mistake them for their pills. Although the majority of these batteries pass through the gastrointestinal tract (GI) without incident, occasionally they will lodge in the esophagus and cause injury.
The most commonly ingested disc batteries are 11.6 mm in diameter or smaller. Other standard battery diameters are 15.6 mm and 23.0 mm. The chemical systems that are in these batteries include mercuric oxide, silver oxide, rnanganese dioxide, zinc and lithium. An alkaline electrolyte is also present and is usually 26 to 45% sodium hydroxide or potassium hydroxide. Lodged batteries may cause local tissue injury through several different mechanisms. Sodium hydroxide or potassium hydroxide might leak from within the battery and cause tissue damage. In addition, electrolysis of sodium chloride can make sodium hydroxide that can cause tissue injury even without actual battery leakage. Another contributing factor might be an electrical current that passes through the tissue. A lodged battery may exert constant pushing against the tissue resulting in tissue damage from the pressure. Although, mercury-containing batteries often leak, no cases of clinical mercury toxicity have been seen.
An X-ray is recommended in all cases of suspected button battery ingestion to confirm the location of the battery. Batteries located in the esophagus require immediate endoscopic removal. Esophageal damage can occur within 6 hours of ingestion. If the battery has passed beyond the esophagus, the patient may be sent home and instructed to inspect the stools to confirm the passage of the battery. The patient should return for a repeat X-ray in 4-7 days if the battery is not seen in the stools, or if the patient develops symptoms such as vomiting, tarry or bloody stools, fever, abdominal pain, or decreased appetite. In some cases, it might take up to 14 days for the battery to pass. Endoscopic or surgical removal may also be considered in cases where the battery stops progressing through the Gl tract. A word of caution: it is sometimes impossible to distinguish between batteries and coins on tile x-ray. This has led to devastating results from delayed removal of the battery.
If you think someone might have swallowed a button battery, call your local poison center immediately at 1-800-222-1222. Poison centers are open 24 hours a day, seven days a week, every day of the year for poisoning emergencies and for informational calls, too.