aka Toxicology Conundrum 035

You are called for advice about a 5 year-old boy (weight: 20kg) was helping his Dad do some minor repairs and maintenance on the family car. The boy drank from what he thought was a cordial container, inadvertently ingesting up to 50 mL of a radiator coolant containing 95% ethylene glycol. The boy is taken to the local health center, which is 3 hours by aeromedical retrieval from a major hospital.

He is ‘totally off his face’ (in the words of the treating doctor) but appears otherwise well.

A better place to pour ethylene glycol... (photo by evelynishere)

Questions

Q1. What is the risk assessment?

Answer and Interpretation

Q2. What are the toxicokinetics of ethylene glycol?

Answer and Interpretation

This is how the body handles ethylene gylcol (ADME):

• Absorption —
  Absorption from the gastrointestinal tract is rapid with peak concentrations occurring at 1-4 hours.
• Distribution —
  Ethylene glycol is distributed to total body water with rapid CNS penetration. It is not protein bound.
• Metabolism —
  Ethylene glycol is metabolised in the liver. It is first converted by alcohol dehydrogenase to glycoaldehyde, which is then metabolised to glycolic acid by aldehyde dehydrogenase. Glycolic acid is further metabolised to glyoxylic acid and oxalic acid.
• Elimination —
  Ethylene glycol has an elimination half-life of about 3 hours.

Ethylene glycol metabolism

Q3. What is the mechanism of ethylene glycol toxicity?

Answer and Interpretation

Q4. What is the clinical course of severe ethylene glycol toxicity?

Answer and Interpretation

Q5. Is decontamination (e.g. with activated charcoal) an option?

Answer and Interpretation

Q6. What investigations may be useful in suspected ethylene glycol toxicity?

Answer and Interpretation

Q7. How is an osmolar gap calculated?

Answer and interpretation

Q8. Does the child require retrieval to a major hospital?

Answer and Interpretation

Q9. What is the definitive treatment?

Answer and Interpretation

Q10. What management options are available pending definitive treatment?

Answer and Interpretation

Q11. What other serious or life-threatening features of ethylene glycol toxicity may require treatment in the unstable patient?

Answer and Interpretation

Q12. What products typically contain ethylene glycol?

Answer and Interpretation

Related LitFL links

• On Call Principles and Protocols – Acid Base Disorders
• Quiz Investigation 008

References

• Barceloux DG, et al (1999). American Academy of Clinical Toxicology Practice Guidelines on the Treatment of Ethylene Glycol Poisoning. Ad Hoc Committee. Journal of Toxicology – Clinical Toxicology, 37 (5), 537-60 PMID: 10497633
• Brent J, McMartin K, Phillips SP et al.  Fomepizole for the treatment of ethylene glycol poisoning.  New England Journal of Medicine 1999; 340:832-838. PMID: 10080845
• Buchanan JA, et al. Massive Ethylene Glycol Ingestion Treated with Fomepizole Alone-A Viable Therapeutic Option. J Med Toxicol. 2010 Apr 27. [Epub ahead of print] PMID: 20422336.
• Caravati EM, et al (2005). Ethylene glycol exposure: an evidence-based consensus guideline for out-of-hospital management. Clinical toxicology (Philadelphia, Pa.), 43 (5), 327-45 PMID: 16235508
• Lepik KJ, et al (2009). Adverse drug events associated with the antidotes for methanol and ethylene glycol poisoning: a comparison of ethanol and fomepizole. Annals of Emergnecy Medicine , 53 (4), 439-2147483647 PMID: 18639955
• Mégarbane B, Borron SW, Baud FJ. Current recommendations for treatment of severe toxic alcohol poisonings. Intensive Care Med. 2005 Feb;31(2):189-95. Epub 2004 Dec 31. PMID: 15627163
• Murray L, Daly FFS, Little M, and Cadogan M. Chapter 3.2 Alcohol: Ethylene glycol; in Toxicology Handbook, Elsevier Australia, 2007. [Google Books Preview]
• Murray L, Daly FFS, Little M, and Cadogan M. Chapter 4.8 Ethanol; in Toxicology Handbook, Elsevier Australia, 2007. [Google Books Preview]
• Sivilotti ML. Ethanol: tastes great! Fomepizole: less filling! Ann Emerg Med. 2009 Apr;53(4):451-3. Epub 2008 Nov 4. PubMed PMID: 18986732.

Life in the Fast Lane Medical Blog - Emergency Medicine education blog

Every emergency department needs to keep a well-stocked pantry. No, not just so that the night staff can survive the torture of middle-of the-night hunger pains. Different types of food can save lives in medical emergencies, or at least help take away a whole lot of suffering…

Here’s a top ten list of food items that should be available in a medical emergency:

10. Cranberry juice

One of the good things about being a bloke is that you’re unlikely to get a urinary tract infection, at least until late in life. But there is good news for women who suffer from recurrent urinary tract infections. A recent Cochrane systematic review suggests that cranberry juice might be useful in the prophylaxis of recurrent urinary tract infections.

So, whatever you do, don’t dis cranberry juice – although as far as I know it doesn’t help with period pain… (NB. video contains expletives)

http://www.youtube.com/watch?v=ORuv1E-71TA

9. Flour

Poisoning with elemental iodine is a very rare medical emergency. Elemental iodine is typically used as a topical antiseptic or for water purification. Severe cases of poisoning by ingestion can lead to gastrointestinal perforation, peritonitis, metabolic acidosis, overwhelming sepsis and death. The diagnosis can be clinched as any starch-containing substance will complex with iodine and distinctive blue vomitus may result.

Starch granules turn blue when stained with iodine (light microscopy)

The absorption of iodine in the (as-yet) asymptomatic patient can be reduced by the ingestion of food consisting of complex dietary carbohydrates. Suitable food stuffs include flour, bread, starch and even milk. However, the administration of food  may be hazardous if perforation has already occurred.

8. Honey

Burns are a bit like snakebites when it comes to home-made cures – people like to do all sorts of strange things to them. In the case of burns that includes smearing them with all sorts of ill-advised substances, most commonly butter or lard (both are a big ‘no-no’…). However, according to the Cochrane Collaboration, honey may actually out-perform other types of wound dressing for superficial and partial thickness burns. Don’t chuck out all your other burn dressings just yet, but the future of burn treatment may be sweeter than you think…

7. Sugar

Granulated sugar can be used to draw fluid out of tissues through osmosis. This can help in the reduction of a paraphimosis. Paraphimosis occurs when the retracted foreskin embarrasses venous and lymphatic drainage from the distal part of the penis, leading to painful swelling and the potential for subsequent ischaemia and necrosis. In the emergency department it is usually more convenient to use gauze soaked in 50% dextrose rather than granulated sugar – the gauze should be wrapped around the paraphimosed penis for an hour before attempting to reduce the foreskin over the glans penis with slow steady pressure. This use of osmosis with granulated sugar – or as one not-always reliable source has suggested to me, dry pancake mix powder – can also help reduce mucosal oedema prior to the reduction of a rectal prolapse (procidentia).

Putting the osmotic effects of sugar aside, the oral administration of sucrose is also useful for procedural analgesia in neonates. Let the baby suck on 1 mL of syrupy sucrose solution (<24% concentration) 2 minutes before, immediately before, and 2 minutes after jabbing him or her with a sharp object.

6. Soft drinks

Given the contribution of soft drinks to the current global obesity and diabetes epidemics, not to mention all the rotting teeth, it is hard to think of them as useful emergency therapies. Nevertheless ‘fizzy’ drinks can come in handy in emergencies.

Apart from being an obvious antidote to hypoglycemia in the alert patient, soft drinks can be a big help when a food bolus gets stuck in someone’s esophagus. Carbonated beverages are thought to help dislodge food boluses by releasing carbon dioxide bubbles that help break up the food. This method is successful at least 60-80% of the time. However, the method may be hazardous if the esophagus is completely obstructed or if the food bolus has been stuck in place for over 24 hours – due to the potential risk of esophageal perforation. And don’t try it if you suspect esophageal perforation has already occurred.

Cola can be be used to help unblock obstructed gastrostomy tubes and free up rusty door hinges.

5. Jam

Jam as a treatment for hypoglycaemia may seem a bit of a cop out given that sugar and soft drinks are also in the top 10. Nevertheless, I prefer jam as the oral therapy of choice for the patient with low blood glucose. It is easy to apply to mucosal membranes of the mouth with low likelihood of aspiration. Furthermore, it is always slightly amusing to watch a patient, just after the paramedics have left, starting to come round and wondering why the hell they’ve got jam smeared all over their face . Of course, any food item containing simple sugars (e.g. soft drinks, lollies, etc.) with help correct hypoglycaemia. Remember to follow it up with a meal containing more complex carbhydrates  – even a sandwich will do.

4. Peas

There are much better uses for frozen peas than defrosting or actually eating them. A bag of frozen peas is really a ready-made ice pack and is a great means of applying cold to a sore and injured joint as it can be easily moulded. After an ankle sprain, apply the bag of frozen peas to the ankle for 15-20 minutes every few hours for the first 24-48 hours after injury. While healing benefits remain unproven for the cryotherapy of sprained joints, it probably does help with pain reduction. Give me a bag of peas instead of ice any day…

3. Vinegar

If you’re at the beach in northern Australia be sure to take along with you some vinegar, or the oldest bottle of corked wine you’ve got. If you feel any sort of painful sensation in the water that could conceivably be a sting from a multi-tentacled box jellyfish (Chironex fleckeri) or a jellyfish that can causes Irukandji Syndrome (Carukia barnesi) vinegar might just save your life, or at least prevent you from entering a world of pain.

Vinegar should be liberally applied to the sting site, ideally 1-2 litres poured continuously for 30 seconds. Vinegar inactivates undischarged nematocysts (stinging cells) that remain on the skin, thus helping to reduce the severity of envenoming. Cola may have some benefit too, but some investigators think that there is something peculiar about organic acids like the acetic acid in vinegar that makes it particularly effective. Urine does NOT work, and methylated spirits actually causes undischarged nematocysts to fire!

A few final points, don’t use vinegar for deactivation of nematocysts from the Blue-bottle (Physalia spp.)  as it doesn’t work, and while vinegar is good on chips it’s not so great on peas…

2. Ethanol

Alcohol is a much-maligned food stuff. But it can be life-saving.

Sometimes alcohol withdrawal can be much more easily managed in the acute setting by giving the patient a bottle of gin rather than exorbitant amounts of benzo’s – although this is often understandably frowned upon by the nursing staff and the Drug and Alcohol team…

A less controversial indication for ethanol is in the treatment of the toxic alcohol poisonings: ethylene glycol and methanol (but not isopropanolol). In parts of the world like Australia where the deluxe option of fomepizole as an antidote is unavailable, ethanol must be administered to buy time until the toxic alcohols can be removed by haemodialysis. Ethanol competes with the toxic alcohols to prevent alcohol dehydrogenase (ADH) from converting methanol into formaldehyde, or ethylene glycol into glycoaldehyde. This is important because it is actually the metabolites of the toxic alcohols that do the real damage. ADH is almost completely blocked at blood ethanol concentrations of 100 mg/dL or 22 mmol.

You may not believe it, but there are some potential downsides to ethanol therapy. Ethanol intoxication may be problematic – but nothing out of the ordinary in the emergency department – and hypoglycemia may occur, especially in children. Enteric administration may be complicated by gastritis and absorption may be less reliable. Intravenous ethanol needs to be pharmaceutical grade (not always readily available) and can cause local phlebitis.

So, how should ethanol be administered for the management of toxic alcohol ingestion?

Enteric administration of ethanol (oral or via nasogastric tube):

• Loading dose (unless the patient is already drunk!): 1.8 mL/kg of 43% ethanol, or 4 x 30 mL shots of vodka in a 70kg adult.
• Maintenance: 0.2-0.4 mL/kg/h of 43% ethanol, or 40 mL shot each hour.

Intravenous administration of ethanol (make 10% ethanol by adding 100 mL of 10% ethanol to 900 mL of 5%d dextrose in water):

• Loading dose (unless the patient is already drunk!): 8 mL/kg of 10% ethanol.
• Maintenance: 1-2 mL/kg/h of 10% ethanol.

The patient is kept in a monitored area with mental state closely followed. Blood or breath ethanol levels should be checked every 2 hours to maintain blood ethanol concentrations of 100-150 mg/dL or 22-33 mmol/L. The infusion is continued until haemodialysis is commenced.

1. Anything!

Food or just about anything organic (including dirt) may be the only hope of survival in one of the nastiest poisoning scenarios around. Paraquat is a herbicide that can lead to a horrible death if as little as a mouthful of the 20% concentrate is ingested. Paraquat has been banned in some countries but poisoning remains a big problem in many developing countries. In addition to corroding the gastrointestinal tract, paraquat can cause progressive metabolic acidosis and multiple organ failure that may be fatal within 24 -48 hours. If the victim survives this phase they still have to endure progressive severe lung injury that rapidly results in pulmonary fibrosis.

Paraquat ingestion is possibly the only poisoning where decontamination overrides all other concerns, including resuscitation or transport to hospital. The victim should swallow any available food or soil immediately to try to adsorb the paraquat and reduce its gastric absorption. In the emergency department, Fuller’s Earth is the traditional decontaminant, but activated charcoal is just as good. And if neither are available, any food will do!

What else do you keep in the pantry for a medical emergency?

See also:

• Removal of tar with sunflower oil, butter or mayonnaise (comments section below)
• Bringing Home the Bacon

Life in the Fast Lane Medical Blog - Emergency Medicine education blog

Having trouble convincing your patients to cut back on their alcohol consumption? They laughed at your lecture on ‘PFO and the consequences‘? They roll their eyes when you detail the dangers of the demon drink?

Maybe this visual aid will be of some help:

Oculotoxic effect of ethanol

Life in the Fast Lane Medical Blog - Emergency Medicine education blog