Knowledge Check

Pseudohyperkalemia is associated with:

Elevated plasma compared with serum potassium concentration

Elevated serum compared with plasma potassium concentration

Reverse pseudohyperkalemia is associated with:

Elevated plasma compared with serum potassium concentration

Elevated serum compared with plasma potassium concentration

True of false: Serum potassium values are always slightly higher than plasma values.

True

False

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Because the process of blood clotting when preparing serum is associated with release of potassium from activated platelets

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What are possible causes of pseudohyperkalemia (more than one answer may apply):

Thrombocytosis

Leukocytosis

Erythrocytosis

True or false: pseudohyperkalemia is associated with essential thrombocythemia, but not reactive thrombosis .

True

False

Which of the following steps may be taken to reduce the risk of pseudohyperkalemia?

Use of a narrow-gauge needle

Fist clenching during blood draw

Short delay time between blood draw and centrifugation

Avoidance of sample storage at cold ambient temperatures

If pseudohyperkalemia is suspected, which next steps are appropriate (more than one answer may apply)?

Measure potassium level in plasma by drawing blood in a tube containing lithium heparin

Measure potassium level in whole blood (using an ABG syringe)

Repeat measurement of potassium level in serum (red top tube)

Measure potassium in an EDTA containing tube

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