Specimen:

Plasma

Collection Medium:

Alternate
Collection Media:

Call laboratory for additional acceptable specimen collection 
containers.

Minimum:

5 mL whole blood from light green top tube or TWO 0.6 light green 
microtubes

Rejection Criteria:

Medico-legal specimens are not accepted.

Testing
Schedule:

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

Analytic Time:

2 hours (upon receipt in laboratory)

Reference Range:

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

Critical value: >300 mg/dL

Comments:

An EVS includes plasma ethanol, plasma osmolality, and a calculated 
osmolality using plasma sodium, glucose and urea.  See links below for 
further information concerning the osmolality gap.  Note: the 
osmolality gap, which is the difference between measured osmolality and 
calculated osmolality, must be >14 before gas chromatography testing 
will be initiated.  An osmolality gap of < or =14 will be called to the 
requesting facility by Pathology staff to discuss findings and 
determine if gas chromatography testing is warranted.  A preliminary 
Ethanol/Volatiles Screen (EVS) will be performed on all sample requests 
for alcohol or glycols (ethylene or propylene) testing by gas 
chromatography.

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: >1,000 mg/dl will be canceled.

CAUTION: Urines containing sugars and contaminated with microorganisms 
may yield a false positive result due to fermentation of sugar to 
alcohol.

References:
(1) Young DS. Effects of Drugs on Clinical Laboratory Tests. 3rd ed.
    Washington, DC: AACC Press; 1990.

(2) Young DS. Effects of Preanalytical Variables on Clinical Laboratory
    Tests. Washington, DC: AACC Press; 1993: 3-120, 3-121.

Methodology:

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

Sample
Processing:

Centrifuge at 3000 RPM for 10 minutes.
Label transport tube with two patient identifiers, date and time of 
collection.

Sample
Storage:

Refrigerate.

Transport
Instructions:

Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
Transport in cooler with refrigerated coolant packs.

Instructions:

Separate plasma from cells ASAP.

CPT Code:

82055

See also:
Alcohol, Plasma
Glycols (Ethylene and Propylene), Plasma

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