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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Electrolytes

Test Code(s): LYTS / LYTE

CPT Code(s): 80051

Test Description: Test Component:

Sodium, potassium, chloride, total carbon dioxide and anion gap.

Included In: Basic Metabolic Panel, Comprehensive Metabolic Panel

Methodology: Ion Selective Electrode and/or Enzymatic

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.

Specimen Requirements

Specimen: Blood

Collection Instructions: Tube must be at least one quarter full.

Collection Container: Preferred: Green cap with yellow ring (PST)
Also Acceptable: Green top, Red cap with yellow ring (SST), Red top

Collection Volume: Preferred: 1 mL
Pediatrics: 0.5 mL

Sample Analyzed: Plasma or serum

Volume Required: Preferred: 0.5 mL
Pediatrics: 0.2 mL

Specimen Processing: Centrifuge.  Redraw specimen if hemolysis is present.  If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial.  Tube or plastic vial must be 25% full and capped.  Refrigerate.

Specimen Transport: Transport specimen to the laboratory. Transport with coolant pack if coming from outreach location.

Unacceptable Criteria: Hemolyzed specimens or whole blood specimens greater than 2 hours old when received by the laboratory are not acceptable.


See individual tests for reference intervals, stability information, or test limitations.

Critical Calls: View

Additional Information:

Anion gap is calculated by subtracting the sum of the chloride and total carbon dioxide from the sodium result.

na, k cl co2 aion

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