Preferred Sample Type
Suitable Specimen Types
- Serum
- EDTA Plasma
- Fluoride Oxalate
- Li Hep Plasma
Specimen Transport
Send to laboratory ASAP **CONTACT LABORATORY BEFORE SENDING**Sample Processing in Laboratory
Take sample to Toxiology or place in Tox box in CSUSample Preparation
Centrifuge and separate plasmaTurnaround Time
Same day if recieved before 2pmSample Stability
4oC
Ethylene Glycol
General Information
MUST CONTACT LABORATORY BEFORE SENDING SAMPLE. FAILURE TO DO SO MAY DELAY ANALYSIS BEING PERFORMED.
The ethylene glycol service is available on site during working hours. In working hours please contact the laboratory (43707 / 0121 424 3707) and ask to speak to a biomedical scientist or clinical scientist before sending a specimen. Out of hours, samples will be sent away for analysis. Out of hours please contact the on-call duty biochemistry consultant via switch (0121 424 2000).
If you wish to discuss a particular patient please bleep the duty biochemist on 2506 in work hours, or the on-call duty biochemistry consultant via switch out of hours.
Label boxes clearly FOR URGENT ANALYSIS.
For external users, please send samples urgently via courier to: Pathology Reception, Birmingham Heartlands Hospital, Bordesley Green East, B9 5SS. Couriers should use the Yardley Green Road Entrance to the hospital. At night, vehicular access is limited but access on foot is available via the pedestrian gate.
Ethylene glycol is a viscous liquid with a sweet taste. Due to the solutes depression of the freezing point of water, ethylene glycol is most commonly used as a de-icing solution or antifreeze in coolant systems. It is also found in brake and hydraulic fluid, is commonly used as a solvent and is found in household cleaners such as window cleaner.
Diethylene glycol is widely used solvent with many uses in manufacturing and is also present (~1%) in antifreeze as an inadvertent by-product of ethylene glycol production. Toxicity and treatment of diethylene glycol production is the same as for ethylene glycol
Poisoning from ethylene glycol poisoning is uncommon but clinically significant due to the associated risk of severe morbidity and lethality and it continues to occur worldwide with many reported poisoning cases of accidental ingestions in children.
GI absorption of ethylene glycol is rapid with onset of symptoms, along with elevated serum concentrations, occurring 20 – 30 min following ingestion. Ethylene glycol undergoes metabolism in the liver by a series of oxidative steps starting with ADH. The slow conversion of glycolic acid to glyoxylic acid results in accumulation of glycolic acid, the main metabolite responsible for development of metabolic acidosis.
In practice, presentation of ethylene glycol poisoning may be nonspecific, especially when patients are not forthcoming about ingestion. Patients may present at any time following ingestion and features from all stages may overlap leading to ethylene glycol poisoning being only one of a wide range of differential diagnosis, especially when other causes of high anion gap metabolic acidosis (HAGMA) are considered.
Early and accurate diagnosis is important in the management of patients presenting with suspected ethylene glycol toxicity to determine the need to start timely treatment with foempizole (an ADH inhibitor) or ethanol.
Indirect testing of ethylene glycol ingestion (e.g. lactate, osmolar gap & anion gap), although potentially helpful, are not accurate estimators of the presence of ethylene glycol and accurate measurement should be sought if ingestion is suspected.
Therefore ethylene glycol measurement is available 24/7 at Birmingham Heartlands Hospital.
Patient Preparation
Sample notes: Please send earliest possible sample for analysis (ie. admission sample if possible).
Notes
Clinical Notes:
As ethylene glycol is absorbed from the gut, a high osmolal gap will initially develop. However, as the glycol is metabolised to acidic products, there will be a decrease in osmolal gap accompanied by an increase in the anion gap. A high anion gap is therefore indicative of a late presentation and progressive development of metabolic acidosis. Antidotal treatment with ethanol or fomepizole and haemodialysis is indicated for patients with evidence of severe poisoning. Treatment should continue until the ethylene glycol concentration is less than 50mg/L and the patient is asymptomatic with a normal pH. Measurements should be repeated a few hours after haemodialysis is stopped as rebound increases in concentrations have been reported. Daily measurement of ethylene glycol concentrations is helpful in determining the appropriate time to discontinue antidotal treatment and/or dialysis.
Ethylene glycol is metabolized to oxalic acid which forms complexes with calcium leading to hypocalcaemia, so close monitoring of the plasma calcium concentration is required.
*Please note, if Methanol is also required please send an additional fluoride oxalate sample for analysis*
Reference Range
<50 mg/L
Specifications
- EQA Scheme?: Yes
- EQA Status: LGC TAK