Plasma

Call laboratory for additional acceptable specimen collection containers.

3 mL whole blood in light green top tube or FOUR Microtainer^® devices

Medico-legal specimens are not accepted.

24 hrs/day, 7 days a week, including holidays.

1 hour upon receipt at reference laboratory

Ethanol: None detected.
Ethanol intoxication begins in the 50-100 mg/dL range.
Ethanol Critical value: >300 mg/dL

Ethylene Glycol: None detected.
Ethylene Glycol Critical value: 10 mg/dL or greater.
Clinical toxicity may be seen with plasma concentrations of >10 mg/dL. Anion gap and arterial blood gas determinations may be useful in determining conversion of ethylene glycol to toxic metabolites.

Includes plasma ethanol and ethylene glycol (ref 3) by enzymatic analysis, plasma osmolality by freezing point depression osmometry and a calculated osmolality using plasma sodium, glucose and urea at no extra charge. See "Osmolality Gap - Calculation and Interpretation" for more detailed information.

If ethylene glycol is present, referral laboratory is contacted by Pathology Resident On-Call or Pathology laboratory staff.

If the ethylene glycol plasma concentration does not account for the high osmolar gap, the pathology resident on-call is contacted. The resident will then investigate the case and contact the referral laboratory, if indicated.

Elevated osmolar gaps may also be caused by methanol, isopropanol, propylene glycol, activated charcoal, mannitol administration, renal failure, and diabetic ketoacidosis, as well as by heavy ethanol consumption with high concentrations of ethanol metabolites (in some cases with little or no ethanol remaining) as may be seen in alcoholic ketoacidosis.

Availability: as needed.

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 "Alcohols Panel (Methanol, Ethanol, Isopropanol, Acetone), 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.

Ethanol
Icterus: No significant interference from bilirubin up to an I index of 60.

Lipemia: No significant interference from lipemia up to an L index of 500.

Hemolysis: No significant interference from hemolysis up to an H index of 200.

Ethylene Glycol
Icterus: No significant interference from bilirubin up to an I index of 15.

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." In addition, the pathology resident on-call is contacted to investigate.

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.

References:
(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.

Enzymatic ethanol using alcohol dehydrogenase; enzymatic ethylene glycol using glycerol dehydrogenase); freezing point depression osmometry (osmolality); calculation (osmolality, calculated).

Centrifuge at 3000 RPM for 10 minutes within 1 hours of collection. Send specimen in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.

Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).

Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Place coolant packs on top of specimen in Styrofoam container to maintain refrigerated temperature.

80320, 83930, 82693

See also:
Ethylene Glycol, Vet, Plasma

See Additional Information:
Osmolality Gap Calculator
Osmolality Gap - Calculation and Interpretation