Clinical manifestations of hypokalemia
The clinical manifestations of hypokalemia are diverse, with the most life-threatening symptoms affecting the cardiac conduction system and the neuromuscular system. Mild hypokalemia on an electrocardiogram presents as flattened T waves and the appearance of U waves, while severe hypokalemia can lead to fatal arrhythmias such as ventricular tachycardia and ventricular fibrillation. In the neuromuscular system, the most prominent symptoms of hypokalemia are skeletal muscle flaccid paralysis and sustained smooth muscle tension, which can involve the respiratory muscles and lead to respiratory failure. Hypokalemia can also cause insulin resistance or hinder insulin release, leading to significant glucose tolerance abnormalities. Reduced potassium excretion decreases the kidney's ability to concentrate urine, resulting in polyuria and urine with low specific gravity.