S3E7: Ethylene Glycol ingestion - PEM/Tox
This month we’re back in the Paeds ED for a (literally) cracking case! First up Mo joins Karl and Stephen for the case. Our Adult In The Room this month, Dr Eleanor Ryan corrects our homework and gives us a few tips on how to optimise the management of this presentation.
For our final segment this month, we are joined by Dr Gergana Semova who talks us through the approach to the sick neonate.
Right then, lets get to it!
The Case
Winter has come and nebulisers are in full swing in the Paeds ED. You are alerted by the triage nurse to a patient he is worried about that he’d like you to have a look at.
Johnny is a 6 year old boy who has just presented to the department with his mother. She found him with a broken snow globe about three hours ago and is concerned he may have ingested some. His mum wasn’t initially concerned, but now feels he is a bit drowsy and not his usual self. Johnny has autism and is non verbal at baseline so it isn’t possible to get an extensive history of the event.
When asked to elaborate, mum tells you that he seemed a little drowsy, off balance, and was having difficulty keeping his attention. He would usually be attentive, alert and active. She kept an eye on him for another hour and there was no improvement, so she decided to attend her local Paediatric ED.
Intoxication - but with what?
Up to 20% of snow globes may be composed of ETHYLENE GLYCOL to prevent freezing in transit. It’s naturally sweet as opposed to other toxic substances kids might get their hands on, meaning they can sometimes drink large quantities. It is incredibly important to get a detailed history of the volume and percentage of the substance consumed.
Check TOXBASE and local guidelines
Initially, get some background. How does he prefer to be referred to? What degree of engagement is he comfortable with? Does he communicate verbally?
But before any interaction, get your facts right! If ever you have a case with ingestion, always consult TOXBASE and print out the local guidelines if they exist. This becomes all the more pertinent in the deteriorating patient when it’s necessary to move beyond the first steps in an algorithm.
Should there be any doubt about treatment or if there is something not right about the case, the National Poison Centre can be contacted directly with questions and queries and are usually more than happy to help out!
Ethylene Glycol - When to treat with what
Treatment for EG poisoning typically involves supportive care, reversal of the metabolic acidosis and calcium loss, and targeting the metabolism of EG.
There are two antidotes for for ethylene glycol poisoning - Fomepizole and Ethanol. Unsurprisingly, ethanol is scarcely used so fomepizole is the drug of choice!
Indications for Fomepizole:
>0.1g/kg ingested by child in 12 hours
>10g of ethylene glycol taken by an adult in the last 12hrs
High anion gap on a gas where the presenting history is unclear should be treated as a suspected ethylene glycol toxic ingestion
Or
Objective evidence of toxic alcohol exposure
Top Tip:
High osmolar gap, normal anion gap: Early presentation.
Normal osmolar gap, high anion gap: Late presentation
And while we’re waiting for blood gas machines to automatically calculate those equations, here’s a quick reminder…
1. Anion Gap = (Na⁺ + K⁺) – (HCO₃⁻ + Cl⁻)
2. Osmolar Gap = Osmolality (measured) – Osmolarity (calculated)
(In other words)
Osmolar Gap = Osmolality - (2 x [Na+]) + [glucose] + [urea])
Low calcium is not required to be replaced as it can cause formation of calcium oxalate crystals (6). The caveat here is if the serum calcium level is low such that
● QTc >500ms or persistent convulsions
○ If this is the case, calcium gluconate IV will be your go to for correcting
Admission or discharge?
In this case the patient became quite sick and required admission to PICU, but what if they present following ingestion and are clinically well?
All patients with suspected or confirmed ethylene glycol ingestion should be monitored for 6 hours.
If patients are asymptomatic after 6 hours and achieve all of the below, they can be safely discharged:
Normal U&E and a normal blood gas
Anion gap <16mmol/L
Osmolar gap <10mOsm/kg
If patients are symptomatic, they will require admission and should not be discharged until they are asymptomatic, and meet the above criteria.
Autism
When speaking to patients and their parents about autism it is important to be sensitive and to focus on getting the nomenclature right. Our team have shared some top tips for approaching autism:
1. Talk about autism positively. There are many positive things about being autistic. Many autistic people see autism as part of who they are, rather than something separate, and prefer to be described as ‘autistic’ or ‘on the autism spectrum’ – rather than as ‘someone with autism’.
2. Do not use negative language like suffering from autism, symptoms and treat. Instead talk about characteristics, support and reasonable adjustments.
3. Every autistic person is different. Try to make sure people know this in all communications.
4. Autism is not a learning disability or a mental illness. But some autistic people also have a learning disability and many people have a mental health problem.
5. Some people on the autism spectrum understand language very literally. Avoid phrases that don’t say what they mean. Like “it’s raining cats and dogs”. Use clear, everyday language.
Pearls from our Adult in the Room - Dr Eleanor Ryan
Use of resources
TOXBASE and the National Poisons Information Centre are invaluable resources and are often underused in toxicology cases
Similarly, making sure the guidelines for management of toxicology cases are printed out and followed step by step can help to optimise treatment in stressful situations in Resus.
Early senior involvement
Ethylene glycol poisoning is rare (despite seemingly featuring heavily on all our exams!). Early senior involvement should be sought once a suspicion of ethylene glycol poisoning arises as management can be tricky and nuanced as we found out in the case!
Communicating with patients with autism
It is imperative to be cognisant of the level of understanding patients with autism have, and to not just speak to their parents. Be guided by their parents who will be able to help you establish an appropriate level of communication between everyone.
Using resources such as play therapists and allied health members can help to facilitate treating children in these high stress situations. Utilising procedure rooms to perform any uncomfortable or painful investigations where available enables the child to be reassured when they return to their bay that they are in a safe environment.
References
Mégarbane B. Treatment of patients with ethylene glycol or methanol poisoning: focus on fomepizole. Open Access Emerg Med. 2010 Aug 24;2:67-75. doi: 10.2147/OAEM.S5346. PMID: 27147840; PMCID: PMC4806829.
Barceloux DG, Krenzelok EP, Olson K, Watson W. American Academy of Clinical Toxicology Practice Guidelines on the Treatment of Ethylene Glycol Poisoning. Ad Hoc Committee. J Toxicol Clin Toxicol. 1999;37(5):537-60. doi: 10.1081/clt-100102445. PMID: 10497633.
Battistella M. Fomepizole as an antidote for ethylene glycol poisoning. Ann Pharmacother. 2002 Jun;36(6):1085-9. doi: 10.1345/aph.1A397. PMID: 12022913.
Lynd LD, Richardson KJ, Purssell RA, Abu-Laban RB, Brubacher JR, Lepik KJ, Sivilotti ML. An evaluation of the osmole gap as a screening test for toxic alcohol poisoning. BMC Emerg Med. 2008 Apr 28;8:5. doi: 10.1186/1471-227X-8-5. PMID: 18442409; PMCID: PMC2390580.
Hodgman M, Marraffa JM, Wojcik S, Grant W. Serum Calcium Concentration in Ethylene Glycol Poisoning. J Med Toxicol. 2017 Jun;13(2):153-157. doi: 10.1007/s13181-017-0598-4. Epub 2017 Jan 12. PMID: 28083813; PMCID: PMC5440316.
Hylander B, Kjellstrand CM. Prognostic factors and treatment of severe ethylene glycol intoxication. Intensive Care Med. 1996 Jun;22(6):546-52. doi: 10.1007/BF01708094. PMID: 8814469.
https://www.toxbase.org/poisons-index-a-z/e-products/ethylene-glycol/
