Potassium ,serum or plasma
(k)

Sample type

Serum preferred

plasma (lithium heparin)

Uses

-Evaluation of electrolyte balance, cardiac arrhythmia, muscular weakness, hepatic encephalopathy, and renal failure

-Diagnosis and monitoring hyperkalemia and hypokalemia in various conditions (e.g; treatment of diabetic coma, renal failure, severe fluid and electrolyte loss, effect of certain drugs).

-Diagnosis of familial hyperkalemic periodic paralysis and hypokalemic paralysis.

Precautions

Non-hemolysed serum is recommended.-

Blood specimens should also be separated from the red-

cells shortly after collection to prevent any leakage of potassium from the intracellular into the extracellular.

-Plasma from anticoagulants not containing potassium is also suitable.

Interfering factors

-Hemolysis

-Laboratory order of draw (lavender top tubes drawn before serum chemistry tubes) this will affect the result.

-Prolonged tourniquet use and hand excercise when drawing blood.

Drugs with high potassium content.-

-Pneumatic tube system issues: speed too high, increased heat exposure in centrifuge.

Arm upward position while collecting blood.-

Triglycerides (>1000 mg/dL) does not affect the results.-

Hemoglobin (>500 mg/dL) does not affect the results.-

Bilirubin (>20 mg/dL) does not affect the results-

Ascorbic acid (10.0mM).-

Pre-analytical errors

1- Long time use of the tourniquet or arm upward position while collecting blood

2-The patient’s history has not been taken carefully and therefore there is information that needs to know and is not available.

3-hemolyzed sample ,unlabeled sample, EDTA or citrate or oxalate plasma tubes.

The corrective actions

1-The sample must be collected in the correct way next time, and if someone else is going to analyse this sample, he must be told what went wrong to expect if there is an increase in the result.

2-You must communicate with the patient and know all the information you need. And next time the history of the patient should be taken carefully.

3-You should reject it and request for another sample

Post-analytical errors

1-Writing a wrong result or wrong name in the report

2-report were sent to incorrect patient

The corrective actions

1-If the report is not delivered to the patient and this error is discovered, the correct result or the correct name must be written, but if the report is delivered to the patient, you must communicate with the patient, apologise to him, and tell him that an error has occurred and replace it with the correct report

2-Communicate with patient ,apologizing for the error, and providing him with the correct report

Reference range

Adults: 3.5 to 5.1 mM (13.7-19.9 mg/dL)