POTASSIUM, whole blood
B-K ATK 7003
Potassium plays a role in the most important enzyme system in the body – the ion pump, which maintains electrical body functions and forms the basic mechanism in e.g. nerve impulses. Potassium regulates heart, muscle and nervous system function, and is essential for the normal rhythm of the heart. It is important in the treatment of high blood pressure. 95% of the potassium in blood is intracellular. Whole blood assay illustrates the long-term intake of potassium. Measurements of extracellular potassium (serum potassium, S-K) and intracellular potassium (B-K) are both important in the assessment of blood potassium levels.
Investigating potassium levels in whole blood. Assessment of the functioning of ion pumps in the body.
5 mL of lithium or sodium heparin blood. Mix the sample well. The tube must not contain any clots. Take trace element samples last in order to cleanse the sampling needle of possible trace element residues. If this is the only test requisition, first take one extra tube.
No fasting is needed. No trace element supplements 12 hours before sampling. The result is normalised to whole blood haematocrit (Hkr) value (B-PVK). The client should determine the haematocrit prior to shipping the sample and write the result on the test requisition.
The Hkr is essential for interpretation of results. Without a measured Hkr value, standard Hkr is used.
Storage and delivery
Ship at room temperature on sampling day (shipping Mon-Thu). Store frozen over the weekend, ship at room temperature.
Reference ranges, calculated
women 35.9 – 49.8 mmol/L (Hkr 0.39)
men 37.8 – 53.5 mmol/L (Hkr 0.42)
The Hkr value affects the reference ranges. The same sample can be used to measure Cu, Mg, Mn, P, Se and Zn.