lhyperkaliémie

Hyperkalemia is a rise in the level of potassium in the blood, typically defined as a serum potassium concentration above 5.0 mEq/L in adults. It can be categorized as mild, moderate, or severe based on the value and clinical context. The condition can be acute or gradual and may occur in people with impaired kidney function, those taking certain medications, or after tissue breakdown or shifts of potassium from inside cells to the bloodstream.

Common causes include reduced renal potassium excretion in chronic kidney disease or acute kidney injury; medications such as ACE inhibitors, ARBs, potassium-sparing diuretics, and nonsteroidal anti-inflammatory drugs; aldosterone deficiency; and situations that shift potassium out of cells like acidosis, rhabdomyolysis, tumor lysis syndrome, insulin deficiency, or intense exercise. Excessive dietary potassium intake is less often responsible when kidney function is normal.

Clinical features range from none to life-threatening cardiac arrhythmias. Early signs may be weakness or paresthesias. Electrocardiograms often show tall peaked T waves, prolonged PR interval, and QRS widening; in severe cases, a sine wave pattern or cardiac arrest can occur. Diagnosis is based on a confirmed elevated serum potassium level and assessment of kidney function, acid-base status, and exposure to contributing medications or conditions.

Treatment depends on severity and risk. Immediate steps include stabilizing the myocardium with intravenous calcium (usually calcium gluconate). Potassium can then be shifted into cells (e.g., insulin with glucose, inhaled beta-agonists, and, if indicated, sodium bicarbonate for acidosis). Moves to remove potassium from the body include loop diuretics, cation-exchange resins such as patiromer or sodium zirconium cyclosilicate, and hemodialysis in severe or refractory cases. Ongoing monitoring, correction of underlying causes, and adjustment of medications are essential for prevention.