|Downtime form:||A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery|
|Plasma Separator Tube 4.5 mL|
Critical value: Ethylene glycol 10 mg/dL or greater
Will be reflexively ordered after Ethanol/Volatiles Screen with an unexplained osmolar gap > 15. May also be directly ordered in cases of suspected ethylene glycol ingestion. This procedure individually quantitates ethylene glycol.
This procedure is not suitable for the detection of other toxic alcohols including methanol and isopropanol. If methanol or isopropanol ingestion is suspected, see test "Alcohol, Plasma." Ethylene glycol is commonly found in many automobile antifreezes.
Ethylene glycol testing for veterinary purposes is available via the University of Iowa Diagnostics Laboratory. Refer to "Ethylene Glycol Vet" entry.
Lipemia: No significant interference from lipemia up to an L index of 1000.
Hemolysis: No significant interference from hemolysis up to an H index of 200.
Two compounds can interfere with the ethylene glycol enzymatic assay: 2,3-butanediol and propylene glycol. 2,3-Butanediol is a compound most commonly found in individuals that chronically ingest large amounts of ethanol. Concentrations of 2,3-butanediol in the range of 0.1 to 7 mg/dL have been observed in studies of patients with history of heavy consumption of ethanol. 2,3-Butanediol serum levels usually decline within 8-12 hours of abstaining from ethanol (see ref. 2). 2,3-Butanediol plasma concentrations in excess of 5 mg/dL have the potential for producing a positive results of ~10 mg/dL on the ethylene glycol enzymatic assay. Such high plasma concentrations of 2,3-butanediol are likely quite rare and would be expected only in individuals with history of very heavy acute and chronic consumption of ethanol.
Propylene glycol is found as a diluent in a number of intravenous medications (e.g., lorazepam, diazepam, etomidate), in some activated charcoal preparations, and also in a limited number of automobile antifreezes. If propylene glycol interference is detected, the ordering provider is notified and the ethylene glycol assay resulted as "Propylene glycol present. Unable to determine presence or absence of ethylene glycol due to interference."
Please contact pathology resident at #3724 (M-F, 08:00-1700) OR #3404 (all other times) with any questions or to determine if further analysis by gas chromatography is indicated.
(1) Eder AF et al. Ethylene glycol poisoning: toxicokinetic and analytical factors affecting laboratory diagnosis. Clin Chem 44: 168- 177, 1998.
(2) Felver ME et al. The presence of 2,3-butanediol in the blood of chronic alcoholics admitted to an alcohol treatment center. Adv Exp Med Biol 132: 229-235, 1980.
(3) Juenke JM et al. Rapid and specific quantification of ethylene glycol levels: adaptation of a commercial enzymatic assay to automated chemistry analyzers. Am J Clin Pathol 136: 318-324, 2011.
(4) Lynd LD et al. An evaluation of the osmole gap as a screening test for toxic alcohol poisoning. BMC Emerg Med 8: 5, 2008.
(5) Krasowski MD et al. A retrospective analysis of glycol and toxic alcohol ingestion: utility of anion and osmolal gaps. BMC Clin Pathol 12: 1, 2012.
Alcohols Panel (Methanol, Ethanol, Isopropanol, Acetone), Plasma
Ethanol/Volatiles Screen (EVS), Plasma
Glycols (Ethylene and Propylene), Plasma