Ingested Foreign Bodies

Children will put absolutely anything in their mouths and boogers are the least of our worries.

This post accompanies the talk I gave to the Royal Children’s Hospital 2018 Clinical Practice Update. Many thanks to Tom Volkman for the invitation to speak.

Most foreign body ingestions take place in children between 6 months and 3 years of age. It’s that phase of their development where they like to explore absolutely everything and often with their mouths. Whilst earthworms do have some nutritional value*  most of the things that children put in their mouths don’t. From personal experience, kids seem to be proud to show you what they have put in their mouths but foreign body ingestion should be suspected if a normally well child has sudden onset coughing or drooling or complains of retrosternal or stomach pain. Fortunately, if it is small, inert and non-toxic then, realistically, caregivers needn’t worry.

He swallowed what?

If you look closely at Arana’s 2001 case series of 325 cases you would see that there have been no end of foreign bodies taken by mouth. Here they are, from the most common:-

• Coins
• Toy Parts
• Jewels
• Batteries
• Needles and pins
• Chicken bones
• ‘Large amounts of food’

Where do things get stuck?

Given that 80% of things pass through without issue it is worth looking at where they do get stuck.

9% of lodged foreign bodies never make it out of the oropharynx and are amenable to removal with a pair of Magills.

20% get lodged in the oesophagus and points of anatomical narrowing – 70% lodge at the level of cricopharyngeus (C6) in the proximal third, 15% lodge in the middle third (T4) and 15% at the distal third.

60% of foreign bodies are found in the stomach. The majority of these will pass as long as they are less than 6cm in length and 2.5cm in diameter. One case series showed that a third of these may still be in the stomach two weeks later.

11% are caught up in the small intestine by the duodenal sweep around the pancreas or at the ileocaecal valve.

Transit time is variable with most case series reporting a delay of between 3.8 and 5.1 days before passage. It’s generally not worth your time getting parents to sieve the toilet bowl, however, as up to 50-60% of objects are never seen again (and are not visualized on follow-up x-rays).

So what happens to the things that don’t pass through? 10-20% require endoscopic removal and a very small percentage require an open approach.

So let’s take a look at some of these foreign objects.

Children are like magpies. They are attracted by bright and shiny objects. What better than that handful of loose change they found down the back of the couch? Most coins will pass without difficulty once they have reached the stomach though this can take up to two weeks. Most children are asymptomatic, and there are several case reports of coins being found as a surprise incidental finding on x-rays taken for alternate reasons.

If they do get stuck then they are most likely to get stuck in the proximal third of the oesophagus. These need to be removed as a matter of urgency as they can cause pressure necrosis and erode into the tracheo-bronchial tree. Some advocate the use of a Foley catheter to aid removal – pass it beyond the coin, inflate and then slowly extract – but this might require sedation and the attendant risks. It is also possible to push the coin beyond the level of cricopharyngeus into the stomach and allow it to pass naturally. Glucagon, occasionally used to facilitate foreign body passage in adults, has not been shown to be efficacious in the paediatric population.

Practical Magic

Once I have confirmed coin ingestion via x-ray – often from triage – I go in to see the patient with a 5c coin hidden in the palm of my hand. Children are more worried about being told off than about the potential harms of swallowing a coin and so I like to play a little game.  After taking a history I gently palpate their belly looking for tenderness. As I reach their belly button I allow the palmed coin to fall into my finger tips. As I deftly extract it I ask, “Was this the coin you swallowed?”. If the answer is in the affirmative I can reassure them and then let teh parents in on the truth – nearly all coins will pass without any problem. If it was not the coin then I get the chance to use my favourite Dad joke – “Everything is fine, but come back if there is no change!”

Number two on the paediatric menu is toy parts. Now, the literature doesn’t actually state what toys are involved but I certainly swallowed at least one piece of Lego. There is no formal data (yet) on the transit time of pieces of Lego. Very occasionally larger toys get swallowed.

Slightly more valuable baubles and their cheaper imitations are next on the list. Most rings and earrings will pass without difficulty if they are small enough (less than 6cm long and 2.5cm wide) though there is a case report of an urgent endoscopy to retrieve a $2000 dollar ring. Imitation jewellery is more of a problem. A number of fake earrings use magnets to hold them in place. If strong magnets, such as the neodymium rare earth magnets, are swallowed in pairs they may be attracted to each other. This leads to potential entero-enteric fistula formation with perforation and peritonitis. Some children, trying to get their belly button pierced before their time, have been known to swallow a magnet to attach to a jewel on the outside. They can be easily detected with plain radiographs though a compass might do in a pinch.

The fourth most commonly ingested item is the button battery. The number of cases reported to the National Capital Poison Center in the US has been steadily increasing. In 1992 around 2300 cases were reported (in the 7 years prior) with only 0.1% of them leading to adverse events and no deaths. By 2010 this had increased to 8600 contacts with 73 patients (0.8%) suffering from major adverse events. There were 13 deaths (0.15%). This may be due to batteries becoming bigger (and therefore more likely to get stuck) and more powerful. As they lodge in the proximal oesophagus they generate hydroxide radicals in the mucosa. This leads to a caustic injury – a rise in pH, saponification and subsequent liquefactive necrosis. Oesophageal perforation has been noted as early as 6 hours after impaction leading to both tracheo-oesophageal fistula formation and the more dreaded aortoenteric fistula. This was the cause of 7 of the 13 deaths reported.

Unfortunately, clinical symptoms correlate poorly with the presence of a battery and so a high index of suspicion is required. If you’ve not yet watched it then you should watch Chantal McGrath’s talk from DFTB17.

Button batteries can look deceptively similar to coins on plain films and so it is worth requesting two views to look for either a step-off or a double ring or halo. If they are in the oesophagus they need urgent removal though some controversy remains if they have made it into the stomach. There have been cases of devastating oesophageal involvement without impaction.

The narrow side of the battery, the negative pole, causes the most necrosis.

And finally, we’ll consider sharp and pointy things – needles and pins. These were some of the most commonly ingested items in the first half of the last century. As disposable nappies made life easier for countless mothers safety pins also became less of a hazard. Depending on how they are swallowed and where they impact they can perforate and migrate leading to anything from an abscess, fistula formation or penetration into a major organ. Because of this they should be removed from the oesophagus regardless of fasting status. Sharp objects are much more likely (15-35%) to lead to morbidity than rounded ones (~1%).

Harry Houdini helped popularise the East Indian Needle Trick at the turn of the last century. If you’ve never seen it then imagine the magician swallowing a packet of 50 needles followed by a length of twine. He then proceeds to bring up the string with the needles threaded along it to the deafening applause of the audience.

Don’t try this at home

A set of threaded needles were already hidden between gums and teeth before the trick began. A small knot on either side of each needle stopped them from falling off. And what about that packet of 50 needles? Do you really believe he swallowed them?

The bottom line

Foreign bodies that need emergent removal:-

• Sharp, long (>5 cm)
• Rare earth magnet/s
• Button battery in the oesophagus (also consider if in the stomach and symptomatic)

Nearly everything else should pass on its own.

*So, what about those worms?

Lumbricus terrestris live for about 6 years in the wild – plenty of time to get juicy and fat.  They are certainly edible and a good source of protein and omega-3 fatty acids.  But we have all heard the saying, “You are what you eat“. Earthworms spend their lives chowing down on compost and soil as well as all of the parasites earth contains.

Perhaps it would be safer to stick with gummy worms – 29 kcals a worm – and much less likely to contain dog roundworm.