In this episode, I’ll discuss when dialysis is recommended to be used to treat ethylene glycol poisoning.
The metabolites of ethylene glycol (glycolate and oxalate) are responsible for the development of metabolic acidosis, neurotoxicity, acute kidney injury, and mortality. Fomepizole effectively blocks the development of these toxic metabolites and is the mainstay of treatment for ethylene glycol poisoning.
Prior to the widespread availability of fomepizole, dialysis was a frequent treatment for ethylene glycol poisoning. Fomepizole’s efficacy eliminates the need for dialysis in some patients, but there is still believed to be a cohort of ethylene glycol toxicity patients who will also benefit from dialysis.
The EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup has recently published their recommendations for when to use dialysis in this setting in the journal Critical Care. This workgroup consists of international experts representing over 30 professional societies.
The experts reviewed over 200 articles and reached consensus to make 19 recommendations or suggestions for the care of patients with ethylene glycol toxicity as it relates to the application of dialysis.
Assuming fomepizole is being used to treat the patient, the authors recommend using intermittent hemodialysis to supplement treatment if the ethylene glycol level is greater than 50 mmol/L or the osmol gap is > 50. The authors make recommendations with different cutoffs if ethanol is used as the antidote or if no antidote is available, but these scenarios would be extremely rare in contemporary practice.
In addition, dialysis is recommended if any of the following are present:
- The glycolate concentration is above 12 mmol/L
- The anion gap is above 27 mmol/L
- The patient presents with coma
- The patient presents with seizures
- The eGFR is less than 45
Guidance for when to stop dialysis is when the anion gap drops below 18 mmol/L, the ethylene glycol concentration drops below 4 mmol/L, and when acid-base abnormalities are corrected.
It is important to keep in mind that dialysis removes fomepizole and that if the dose is not adjusted to account for dialysis the patient is at risk of inadequate inhibition of metabolite formation and toxicity would be worsened as a result.
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