Human albumin: Clinical advice on ethylene glycol

What is ethylene glycol?

• Ethylene glycol is an alcohol generally used as a coolant, mixed with water and other solutions.
• It is metabolised by the same enzyme pathway used to metabolise ethanol and other alcohols, using alcohol dehydrogenase and aldehyde dehydrogenase in the liver. It is metabolised to Glycolic acid and Oxalic acid which, along with unmetabolised ethylene glycol (around 20% of a dose) is excreted by the kidneys.

How is it toxic?

• There are three main toxic effects of ethylene glycol:
  1. CNS effects similar to ethanol;
  2. A high anion gap metabolic acidosis; and
  3. Formation of oxalic acid crystals, which can damage kidneys and other tissues and adsorb calcium ions. It can lead to acute renal failure.

How do I recognise ethylene glycol toxicity?

• Poisoning should be considered when a patient has received IV albumin in the last 72 hours and either
  • Develops an unexplained high anion gap metabolic acidosis;
  • Has symptoms consistent with alcohol intoxication but does not have an expected level of ethanol in their blood; or
  • Develops acute renal failure without an alternative explanation.
• If you are concerned regarding a possible episode of poisoning, check if your laboratory is able to measure ethylene glycol levels from a blood sample.

How can ethylene glycol toxicity be treated?

• IV or oral ethanol can be used to block the metabolism of ethylene glycol. Check with your local Intensive Care Unit or Poisons Information Centre for specific advice on the appropriate dose.

What is the risk of patients previously treated with albumin?

• Toxicity due to ethylene glycol occurs acutely and delayed effects beyond 72 hours would not be expected. For this reason patients who received albumin more than 3 days ago and are well do not require investigations to be performed and can be reassured.

What do I do until new stocks of Albumex arrive?

• Clinicians should carefully consider the clinical need for albumin usage during this period, as well as any alternative therapy that could be substituted, such as the use of alternative volume expanders.
• The highest risk would be anticipated in those patients requiring the largest volumes of albumin.
• The Blood Service is also increasing the manufacture of Clinical Fresh Frozen Plasma to meet any extra demand.