Hüpokaleemiat

Hüpokaleemiat refer to conditions characterized by low potassium levels in the blood. Potassium is an essential electrolyte involved in nerve and muscle function, including the heart. Normal serum potassium typically ranges from about 3.5 to 5.0 mmol/L; hypokalemia is generally defined as a concentration below 3.5 mmol/L, with levels classified as mild, moderate, or severe.

Common causes include gastrointestinal losses from vomiting or diarrhea, use of certain diuretics (especially loop and thiazide diuretics), renal conditions that promote potassium loss, and shifts of potassium into cells due to insulin, beta-adrenergic activity, or metabolic alkalosis. Inadequate dietary intake alone rarely causes significant hypokalemia but can contribute when combined with losses. Magnesium deficiency can worsen hypokalemia and complicate treatment.

Clinical features vary with severity and may include muscle weakness, cramps, fatigue, constipation, and, in more serious cases, paresthesias or paralysis. Hypokalemia can also disrupt cardiac electrical activity, leading to arrhythmias; this risk increases with lower potassium levels and in the presence of other electrolyte disturbances or cardiac disease. Electrocardiogram findings can include flattened or inverted T waves and the appearance of U waves.

Diagnosis relies on serum potassium measurement, assessment of underlying causes, and evaluation for accompanying electrolyte or acid-base disorders. Treatment aims to correct the potassium deficit and address the underlying cause. Mild hypokalemia may be treated with oral potassium chloride, while more severe cases or symptoms require intravenous replacement, typically with careful monitoring of heart rhythm and rate of infusion to avoid overcorrection. Management often includes correcting magnesium deficiency if present and reassessing medications that contribute to potassium loss.

Prognosis depends on timely diagnosis and treatment, the severity of the deficit, and control of the underlying cause.