A few questions have been raised on the actual danger posed by small and medium button batteries. Some misconceptions have been circulating about:
- how dangerous they are,
- how the body responds, and
- the type of treatment needed if ingested or inserted.
Button batteries can cause serious injuries if swallowed, and we know that children are doing so frequently. The larger (20mm) coin-sized batteries are the most hazardous because they are more likely to get stuck in a child’s oesophagus and burn through the tissue. But smaller button batteries (16mm or less) can also be responsible for significant injuries if swallowed, or inserted in places like the nose or ear.
Reducing access to all batteries, regardless of size or chemistry, is essential.Dr Ruth Barker
US website poison.org explains the injury mechanisms for battery injuries, summarised below:
Batteries cause tissue injury through three interacting mechanisms, although the relative contribution of each is unclear. These mechanisms come into play when a battery is lodged in the digestive tract, ear, nose or other orifice, rather than free-floating and in transit. The mechanisms, listed in the likely order of importance, include:
- Generation of an external electrolytic current that hydrolyses tissue fluids and produces hydroxide at the battery’s negative pole, (akin to oven cleaner #)
- Leakage of battery contents, especially of an alkaline electrolyte, and
- Physical pressure on adjacent tissue
# Oven cleaner has sodium/potassium hydroxide as the main constituent.
Dr Ruth Barker, a paediatric emergency physician and Director of the Queensland Injury Surveillance Unit, has provided some insights:
Hazard relative to coin-sized batteries
Small to medium sized button batteries are a lower risk than the 20mm ones – due to their smaller size, lower charge and different chemistry – but they still present a hazard.
Data from the USA is the most comprehensive. Dr Toby Litovitz has collated cases of button battery ingestions reported in medical journals, media reports and through reporting to the National Battery Ingestion Hotline. Of these collated severe and fatal cases:
With many instances, the battery size is unknown, so these numbers represent the minimum number of cases attributable to small-medium button batteries.
What happens in the digestive tract
Coin-sized 20mm batteries are the most likely to lodge in the oesophagus. Smaller batteries are more likely to pass into the stomach, but can also lodge in the oesophagus, causing similar injuries to the larger batteries.
Large or small, if the battery becomes stuck and has at least 1.2 V of residual charge, hydrolysis will occur and caustic tissue damage will result. The resulting ‘liquefactive necrosis’ eats through tissue even after the battery has been removed. This can result in erosion into the airway or large vessels. The majority of fatalities have involved catastrophic bleeding from major vessels, days to weeks after battery ingestion. An 11-month old-child in Western Australia survived an aortic bleed 4 weeks post-battery removal, the only patient reported to have survived an aorto-oesophageal fistula.
Some misconceptions exist that stomach acid counteracts the caustic battery action and negate the injury. But Dr Barker says it is more that ingested batteries are not as dangerous ‘in motion’. Unlike the oesophagus, once in the stomach a battery (of any size) does not usually sit against tissue long enough to burn.
Dr Barker knows of one US fatality (a child less than 12-months old) reported where a battery (20mm) was in the stomach at time of presentation, but had seared a hole in the oesophagus prior to passing further.
Damage due to the liquefaction necrosis caused by a battery’s sodium hydroxide, can be ongoing, despite the battery passing. So this can be a silent danger when everyone thinks the battery has successfully passed.
For large batteries, consideration should be given to endoscopy to inspect for oesophageal damage, even if the battery is in the stomach, and particularly if the time of ingestion is unclear.
Medical or surgical treatment
Dr Barker explains that many factors need to be considered when determining appropriate treatment:
1. Often, time of ingestion is unknown, or inaccurately reported
2. Residual charge is impossible to estimate unless the battery has just come out of its packaging
3. When making a decision to surgically remove a battery, there are multiple factors to take into account:
- The age and size of the child (diameter of the digestive tract)
- Previous oesophageal injury that may have caused narrowing
- Position of the battery on X-ray
- Symptoms (difficult to ascertain in a preverbal child)
- Size of the battery
2019 report of a Canberra family
Medium-sized batteries (11mm) were implicated in the recently reported Canberra case of 11-month-old Edward Rumble, and a question was raised about the appropriateness of invasive medical management.
On reading the media article, Dr Barker’s take is that one battery is likely to have been in the stomach, but that a decision was made to retrieve the battery and inspect for oesophageal/stomach damage based on some of the factors above. Many ingested objects (not just batteries) pass the pylorus (stomach outlet) but this can be unpredictable, so there is often a difficult decision to be made on whether to remove a battery when the child is well, versus waiting til things deteriorate.
Baby Edward reportedly sustained some internal burns and bleeding, but has reportedly made a full recovery. The responsible product has been recalled.
A serious case from North Queensland
In 2010, four-month-old Queensland baby, Oscar swallowed a ‘1 cm’ battery. Just a 14-hour delay in removing the battery resulted in spinal damage and the infant spent eight months in a full-body cast. At five years old, Oscar could walk but he will reportedly have severe restriction of movement for the rest of his life, unable to fully raise his head.
New US research
New research in the USA by Dr Racha T. Khalaf (yet to be published) points to numerous incidents of gastric injury from button battery ingestion – cited as 60% of patients where the battery was found in the stomach.
The findings are based on records from 68 children treated at four paediatric hospitals between 2014 and 2018. All had an endoscopy procedure to retrieve a button battery from the stomach. Many had no symptoms when they arrived at the hospital.
“We saw one major adverse event,” Khalaf said. In that case, she explained, the battery created a hole in the child’s stomach because it sat there for so long. (Doctors estimated it had been there for nearly five days.) But even in less-severe cases of stomach-lining erosion, the concern is that the damage could progress: Doctors can’t know if or when the battery will pass.
Insertions into the body
Insertions in places like the nose or ear are usually smaller batteries. Injuries, such as perforations of the eardrum or nasal septum, can require reconstructive surgery and can significantly impact a child’s hearing and short- and long-term health.
Anecdotally, zinc air chemistry is used for the vast majority of small (5mm) hearing aid batteries and these are frequently implicated in nose/ear insertion. Dr Barker notes that there are many medical papers describing damage from insertion of small batteries into the ear or nose, but none that correlate product and battery chemistry with injury outcome.
Managing the risk
There have been two fatalities in Australia from button battery ingestions (in 2013 and 2015), but an ongoing study by the Australian Paediatric Surveillance Unit estimates there is approximately one serious injury a month in Australia due to ingested or inserted button batteries.
Medical management is complex, invasive and at times, attempting to snatch success from the jaws of disaster. Dr Barker believes this is why reducing access to all batteries, regardless of size or chemistry, is essential.
Both the Australian Competition and Consumer Commission and Standards Australia are currently considering strategies to address button batteries. Better product standards, and possibly regulation, will help ensure access to batteries is much harder.
Safe product design is always a more effective option than trying to influence user behaviour, or having to surgically remove a product from someone.