12. Potassium - common data for the parameter, indications for investigation, principles of the analytical methods, reference ranges, interpretation of results.

potassium - common data for the parameters, indications for investigation, principles and analytical methods, reference ranges, result interpretation.

K main cation in ICF. It is involved in: ICF balance, nerve impulse transmission, muscle contraction, glycogen formation, protein synthesis, pH balance. Levels of potassium are regulated by the kidney

Range is 3.5-5.5 mmol/l

indications for investigation:

Hypertension, Cardiac arrhythmias, Diuretic and laxative medications, Acute and chronic renal failure, Diarrhea and vomiting, Disturbances in acid-base balance, Disturbances in water electrolyte balance

Principles and analytical methods:

1. Flame photometry: based on light emitted when metal ions tested to show which are present and how much. Different metal ions give a different colour and intensity due to concentration.
2. Potentiometer: used to measure voltage
3. Spectrophotometry: used to measure the amount of light absorbed by substance

Result interpretation:

Hypokalaemia: <2.5 mmol/ls: due to stress /myocardial infarction, Diuretics: furosemide and Thiazide, Metabolic acidosis, Hypomagnesemia, Primary hyperaldosteronism, vomiting

Hyperkalaemia: Increased intake of K, Massive muscle injury, Digitalis intoxication, Diabetic ketoacidosis, Renal failure, Addisonian crisis