Laboratory Test Reference Guide

Laboratory Information

Test Name

Potassium

Synonyms

K

External Price (excl. GST)

2.63

Specimen Collection

Adult Specimen

Heparin (light green), SST (gold)

Paediatric Specimen

0.3 ml Heparin (light green) or Plain(red).

Test Information

Department

Biochemistry

Test Availability

Mon - Sun, 24hrs

Laboratory Turnaround Time

3 hrs

Method

Cobas 6000 indirect ion selective electrode "T"labs Vitros 350 direct ion selective electrode

Unit of measurement

mmol/L

Reference interval

< 1 month   = 4.5 – 6.0 mmol/L
> 1 month   =  3.5 – 5.2 mmolL
(From ARQAG October 2009)

Uncertainty of measurement

±0.2 mmol/L

Additional Information

The Choosing Wisely recommendations include the following:

Don’t do regular tests but test in response to clinical questions.

Don’t do repeat tests if clinically stable; repeat only when clinically indicated.

Do not repeat laboratory tests for patients transferred into the ED who have laboratory results within reference ranges available from outside hospital.

Don’t do screening tests in low risk patients undergoing low risk surgery.

We also recommend:

Do not repeat the creatinine and electrolytes if they were normal unless there are clinical indications to suggest a likely change (eg hypotension, reduced urine output).

Micro samples may have elevated potassium due to haemolysis.

Minimum Volume

0.1 ml heparin plasma or serum.

Electronic Information

Registration Code

POT

HL7 mapping code

$POT

LOINC Code

2823-3