Potassium K (urine) Laboratory research

General Information

The largest amount of potassium is excreted by the kidneys; Excretion of K+ depends on the amount of potassium intake. At the level of the nephron, potassium is subject to three main mechanisms: glomerular filtration, total reabsorption in the proximal tubule, and secretion in the distal tubule. Excretion of potassium depends exclusively on filtration and secretion processes.

Metabolic alkalosis is the most common manifestation of potassium loss.

Loss of potassium by the kidneys occurs in several cases:

• An excess of mineralocorticoid hormones
• Renal tubular injuries
• tubular fluid overload with Na+
• Alkalosis

In acute renal failure, potassium is not filtered glomerularly and is not excreted in sufficient quantities through the tubes. Extrarenal dialysis is the safest way to correct potassium levels in all patients with severe hyperkalemia.