Ethanol/Volatiles Screen (EVS)

Label Mnemonic:	EVS
Epic code:	LAB604
Downtime form:	A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Chemistry
6240 RCP
356-3527

Specimen(s):

Plasma

Collection Medium:

Plasma Separator Tube 4.5 mL

Alternate Collection Media:

Call laboratory for additional acceptable specimen collection containers.

Minimum:

3 mL whole blood from light green top tube or TWO Microtainer^® devices

Rejection Criteria:

Medico-legal specimens are not accepted.

Delivery Instructions:

Deliver to laboratory within 1 hour of collection.

Testing Schedule:

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

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

None detected.  Ethanol intoxication begins in the 50-100 mg/dL 
range.

Critical value: >300 mg/dL

Comments:

Includes plasma ethanol 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.

Samples with unexplained osmolar gap greater than 15 have "Ethylene glycol, plasma" (by immunoassay) run reflexively. For those samples, 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 clinical service, 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.

Test Limitations:

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: >200 mg/dL will be canceled.

Very high concentrations of lactate (> 30 mEq/L) and lactate dehydrogenase (< 8,000 U/L) have potential to produce falsely elevated ethanol results.

References:
(1) Eder AF et al. Ethylene glycol poisoning: toxicokinetic and
    analytical factors affecting laboratory diagnosis. Clin Chem 
    44: 168- 177, 1998.

(2) Lynd LD et al. An evaluation of the osmole gap as a screening test
    for toxic alcohol poisoning. BMC Emerg Med 8: 5, 2008. 

(3) 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.

(4) Nine JS, Moraca M, Virji MA, Rao KN.  Serum-ethanol determination:
    comparison of lactate and lactate dehydrogenase interference in 
    three enzymatic assays.  J Anal Toxicol 19: 192-196, 1995.

Methodology:

Enzymatic (ethanol); freezing point depression osmometry (osmolality); calculation (osmolality, calculated)

CPT Code:

80320

See Additional Information:
Osmolality Gap Calculator
Osmolality Gap - Calculation and Interpretation
Chemistry Critical Lab Values