Hypokalemia Symptoms

Hypokalemia means a serum potassium concentration below 3.5 mmol/L (or mEq/L). Potassium is concentrated inside cells and helps establish the electrical gradient needed for skeletal muscle contraction, gastrointestinal motility, and cardiac conduction. As the serum level falls, muscle cells become less excitable. The client may first describe vague fatigue or heavy legs, then develop weakness, cramps, paresthesias, or, with a more severe deficit, paralysis. Smooth-muscle activity can also slow, producing constipation or ileus. Impaired renal concentrating ability may contribute to polyuria. The heart is the priority organ because potassium influences myocardial repolarization. Hypokalemia may produce flattened T waves or U waves and can trigger ectopy or more dangerous dysrhythmias. A client can look relatively well while the ECG is becoming unsafe; the potassium value, symptoms, rhythm, recent losses, and kidney function must be interpreted together. The serum value may fall because potassium has been lost through the gastrointestinal tract or kidneys, or because potassium has shifted into cells. Vomiting, diarrhoea, diuretic therapy, and some medication-related shifts are common clinical clues. Correcting the number without identifying ongoing losses can produce only...