The rate of severe poisonings from battery ingestion among U.S. children has risen in the past 25 years, along with the growing use of lithium “button” batteries in a wide range of consumer products, new research shows.

The number of children who die or suffer serious injuries each year remains quite small, but such severe cases are accounting for a growing proportion of all button-battery poisonings, researchers report in the journal Pediatrics.

The findings underscore the importance of keeping the small, disc-shaped batteries out of children’s reach, say the investigators, led by Dr. Toby Litovitz of the National Capital Poison Center in Washington, D.C.

Between 1985 and 2009, U.S. poison-control centers received 59,535 reports of button-battery ingestion. The yearly incidence rates fluctuated, with no pattern of an increase over time.

However, the rate of severe poisonings clearly rose, Litovitz and his colleagues found.

From 1985 through 1987, just 0.06 percent of button-battery ingestions were fatal or had “major” complications - mainly damage to the esophagus that often required surgery and led to prolonged problems with breathing and eating.

That figure increased nearly seven-fold by the three-year period from 2007 to 2009, when 0.44 percent of all button-battery swallowings proved fatal or severe.

Children younger than 4 were the most frequent victims, and in nearly all cases of severe complications, a particular type of button battery - the 20-millimeter lithium cell - was to blame.

Button batteries are used in a wide variety of products, including cameras, remote controls, watches, hearing aids, toys and even musical greeting cards. Compared with other types of button batteries, 20-mm lithium cells are larger (about the size of a nickel) and more apt to become lodged in the esophagus if swallowed.

Once stuck in the esophagus (the tube through which food passes), the lithium battery creates an electrical current that burns the tissue surrounding it. In contrast, batteries that make it through the esophagus usually move harmlessly through the digestive tract until they are passed.

The current study found that in the majority of fatal or severe injuries, no one had seen the child swallow the battery. And because the symptoms of poisoning are non-specific - such as fever, vomiting, poor appetite and lethargy - doctors often initially misdiagnosed the problem.

To further investigate the circumstances surrounding severe cases of battery poisoning, Litovitz and his colleagues combed through reports to the National Battery Ingestion Hotline and cases published in the medical literature. They identified 13 fatal and 73 serious battery poisonings that occurred between 1977 and 2009.

Of the 13 fatalities, nine occurred between 2004 and 2009, the researchers found. And of all fatal or severe poisonings from 2000 onward, 92 percent of the batteries identified were 20-mm lithium cells.

The fact that these poisonings can be difficult to diagnose underscores the importance of prevention, according to Litovitz and his colleagues.

They warn parents to keep not only loose batteries out of children’s reach, but also the household products that contain the batteries. In about 62 percent of cases where a young child swallowed a button battery, the child fished the battery out of a household item.

For an additional barrier, the researchers advise parents to place strong tape over the battery compartment of all household products.

They urge extra caution with any 20-mm lithium cell batteries, which can be recognized by their imprint codes - usually CR2032, CR2025 or CR2016.

The researchers also call on manufacturers of the variety of products that use button batteries to redesign the battery compartments - both so that a young child cannot open them, and so they do not spontaneously open if the product is dropped.

“The popular belief that only toys need to be safe for children is ill- construed,” the researchers write.

SOURCE:

Pediatrics, June 2010.