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Epic Test Code LAB29 Lithium

Performing Location(s)

BMC

Synonyms

Eskalith, Li, Blood, LiCO2

Specimen Type

Serum

Preferred Container

Red top tube

Blood Tube Draw Volume

Min 50% draw volume  

Minimum Volume to Submit for Testing

0.5 mL Serum

  • Multiple test can be performed from this volume. For question please contact the lab at 547-3975

Storage Requirements

Sample tubes should be centrifuged within 2 hour of collection followed by transfer of the serum to a labeled plastic, aliquot tube.

See Causes of Rejection for temperature requirements.

Transportation Needs

Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements". 

Causes for Rejection

Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes
Specimen collected in anything other than a red top tube
> 7 days Refrigerated
> 4 hrs Room Temperatue
> 1 year Frozen
Hemolysis > 200 mg/dL HgB
Lipemia > 2000 mg/dL Trig
Bilirubin > 45 mg/dL Bili

Limitations

An increase in serum sodium concentration of 23 mmol/L from a nominal serum concentration of 140 mmol/L will produce biases of +0.06 and +0.05 mmol/L at lithium concentrations of 0.70 and 2.10 mmol/L, respectively.

A decrease in serum sodium concentration of 23 mmol/L from a nominal serum concentration of 140 mmol/L will produce biases of -0.06 and -0.05 mmol/L at lithium concentrations of 0.70 and 2.10 mmol/L, respectively.

Reference Values

Population Units Therapeutic  Range High Critical Value

<60

 mmol/L 0.6 - 1.2 >1.5

≥60

 mmol/L 0.4-0.8 >1.2
 

Other Interpretive Information
Therapeutic lithium concentrations vary significantly, depending on the individual.
A therapeutic range of 0.60 to 1.20 mmol/L includes effective serum/plasma concentrations for many patients; however, some individuals are best treated at concentrations outside this range.
Concentrations of 1.20 to 1.50 mmol/L signify a warning range, and a concentration in excess of 1.50 mmol/L in a specimen drawn 12 hours after the dose indicates a significant risk of intoxication.
Concentrations greater than 2.00 mmol/L are often associated with toxic symptoms.
Note: The physician must ultimately determine the most appropriate lithium therapeutic range for each patient

 

Days of Analysis

All

Available STAT

Yes

Additional Information

Collection Guideline:

At the start of therapy, the recommendation is to monitor as follows:

First 2 weeks: monitor every 3-4 days
20 weeks: monitor weekly, adjusting dose as needed
6 weeks to 3 months: monitor monthly
3 months: monitor every 3-6 months once patient is well stabilized on given regimen

 

Additional Information:

Lithium, the third element in the periodic table, is used primarily to treat the manic phase of affective disorders, mania, and manic-depressive illness. The precise mechanism of action of lithium as a mood-stabilizing agent is not known. Lithium is administered in capsule, syrup, or tablet form as salts of either carbonate or citrate. It is readily absorbed from the gastrointestinal tract and does not bind appreciably to plasma proteins. Peak plasma concentrations are reached 2 to 4 hours after oral administration. Approximately 95% of a single dose of lithium is excreted in the urine within 6 to 12 hours, with the remainder being slowly excreted over the next 10 to 14 days.

 

Lithium concentrations are monitored to ensure patient compliance and prevent toxicity. Because there is a narrow therapeutic range of about 0.60 to 1.20 mmol/L, with significant risk of toxicity occurring above 1.5 mmol/L, determination of lithium concentration is crucial in the management of patients on lithium therapy. Since plasma values vary relative to time of last dose, a standardized 12-hour post-dose serum lithium concentration has been recommended to assess adequate therapy.

 

 

Methodology

Beckman AU/Dx Series

CPT Code

80178

Last Updated

19-DEC-24 MS