SP2 Management of ethylene glycol poisoning in an adolescent: a clinical pearl
Authors: Wilson Nicola 
Published: August 2020

Situation

16 year old girl admitted with suspected ingestion of ethylene glycol. She was treated with fomepizole and continuous renal replacement therapy (CRRT).

How the Pharmacy Team Contributed

Ethanol was prescribed until fomepizole arrived. The volume of ethanol to be administered was calculated wrongly by the consultant due to confusion about the available strength. The Paediatric Intensive Care Unit (PICU) pharmacist intervened and the correct dosage information was given.

PICU pharmacist used Toxbase to determine the correct treatment of ethylene glycol poisoning and advised on dosing regime, including adjustment due to CRRT. The pharmacist facilitated prescribing on the electronic system (added drug to system, set up administration instructions and assisted with prescribing – pharmacist was not an Independent Prescriber). This allowed medical staff to concentrate on resuscitation, monitoring cardiac function, inserting intravenous lines and obtaining access for CRRT.

The PICU pharmacist and pharmacy technician co-ordinated initial supply of fomepizole. Fomepizole is usually ordered directly from the manufacturer during office hours. The patient presented in the early evening so further supply had to be obtained from a hospital hundreds of miles away after referring to the Rarely Used Medicines list. Pharmacist contacted appropriate on-call pharmacist and arranged for transfer of medicines via courier. Pharmacy technician arranged for further supply form the manufacturer the following day.

Pharmacy technician arranged supply of additional dialysis fluids for CRRT due to the higher than usual administration rate.

Without contribution from the pharmacy team the patient is likely to have been given the wrong dose of ethanol and fomepizole, and there would have been delay in initiation of treatment followed by an interruption, as it was wrongly assumed that it was kept as stock in the adjoining ‘adult hospital’ and subsequent supply from a local hospital would not have been sought by ward staff until original supply ran out.

Outcome

Ethylene glycol poisoning was confirmed on laboratory testing. Levels of ethylene glycol fell steadily over 36 hours, allowing CRRT and fomepizole to stop. Patient was discharged from PICU after 48 hours with no apparent long-lasting effects, but was referred to various specialities including renal, gastroenterology and psychology.

Patient and family denied knowledge of intentional or accidental ingestion. Police investigation was inconclusive.

Lessons to be Learned

Larger supplies of fomepizole are now kept in stock within Health Board. Supplies were missing from emergency cupboards when stock was needed, despite being on stock lists, necessitating courier fees to transfer stock from elsewhere. Procedures reviewed to ensure that stock is available in emergency cupboards at all times.

This patient demonstrated that current (target) stock levels of fomepizole were inadequate for providing treatment during CRRT as the required doses are substantially higher (administered every four hours rather than every twelve hours) and would have lasted less than 12 hours for this average sized teenager. National Rarely Used Medicines list was updated to reflect actual stock levels and other hospitals increased their stockholding due to the realisation that existing stock was inadequate and that further supplies were hard to obtain out of working hours.