#Istat potassium Activator

The source of potassium is usually cells but can be contaminants. Some authors have tried to define pseudohyperkalemia as a difference between serum and plasma potassium concentrations of more than 0.4 mmol/L when samples remain at room temperature and are tested within an hour of collection. Pseudohyperkalemia is suspected when the laboratory value of the measured potassium is high but the patient does not manifest signs of hyperkalemia such as abnormal electrocardiogram.

Platelets release potassium during the clotting process, resulting in higher (0.36 В± 0.18 mmol/L) potassium concentrations in the serum as compared to plasma.

#Istat potassium Activator

Samples can be collected in plain silicone coated glass/plastic tubes, gel separator tubes with or without clot activator for serum estimations (with thrombin-based clot activator for stat estimations) or in tubes containing lithium/sodium/ammonium heparin as an anticoagulant for plasma estimations with or without gel separator.

Both plasma and serum can be used to measure potassium. Potassium is usually measured using an Ion-selective electrode (ISE), which converts the activity (or effective concentration) of the ion dissolved in solution into an electric potential measured by a voltmeter.