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Potassium (K) |
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Potassium (K) |
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Potassium metal |
Indications for performing this test: Potassium is one of the electrolytes included in a standard serum biochemistry panel. A standard serum biochemistry panel will include Na, K, and Cl. These important electrolytes should all be considered together along with any acid base abnormalities and the anion gap. Although an electrolyte pattern is rarely diagnostic, it is useful in the assessment of the severity of body fluid disorders and may be very important in the implementation of fluid therapy. Potassium is the major intracellular cation. In order for normal cardiac and neuromuscular function to be maintained, potassium levels must remain in a narrow range. Shifting of K into and out of cells helps to regulate serum K. That is why serum K is not a reliable indicator of total body K. |
Interpretation of serum potassium levels:
Hyperkalemia
- Decreased glomerular filtration or urine obstruction
- Hypoadrenocorticism
- Acidosis: During acidosis, H+ ions are taken into the cell in exchange for K in an attempt to regulate the blood pH. This hyperkalemic condition will correct itself once the acidosis is corrected.
- Altered membrane permeability causing a leakage of intracellular K.
- Insulin deficiency: Insulin facilitates K entry into the cell. In diabetics, we do not see a hyperkalemia due to the excretion maintained by the kidney. When insulin therapy is initiated, there may be a resultant hypokalemia. In some cases, insulin can be used to clinically manage a hyperkalemia.
- Hemolysis: The pig, horse, cow, and some dog breeds have high concentrations of K in their erythrocytes.
- Marked thrombocytosis due to the release of K by the platelets.
- Hyperkalemic Periodic Paralysis (HYPP) in horses. Click here for more facts on HYPP : http://www.vgl.ucdavis.edu/~lvmillon/hypp/hypp_facts.html
Ohio State University
Bladder stones can cause obstruction of urine flow, and thus hyperkalemia. In this case, the chronic pyelonephritis caused mineralization and stone formation.
Hypokalemia
- Excessive gastrointestinal losses due to vomiting or diarrhea.
- Excessive urinary losses due to diuresis or diabetes mellitus.
- Dietary deficiency
- Anorexia especially in herbivores and cats
- Hyperadrenocorticism (very rarely find low potassium)
- Profuse sweating in horses
- Alkalosis, by the same process described above for acidosis.
- Insulin therapy as mentioned above.
- Artifact of flame photometer determination of K concentration. Occurs with lipemia or hyperproteinemia.
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For more information . . .
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Diuresis can cause
hypokalemia. |
