Which sign is most consistent with hyperkalemia?

Which sign is most consistent with hyperkalemia?

• A. Cardiac dysrhythmias
• B. Hypotension
• C. Rash
• D. Nausea

Answer: (A)

Hyperkalemia directly disrupts how cardiac cells conduct electricity. Elevated extracellular potassium reduces the gradient across the cell membrane, which alters the resting membrane potential and depolarization in cardiac myocytes. This leads to changes in conduction and a tendency for dysrhythmias. Clinically, the most consistent and critical sign is cardiac dysrhythmias, reflecting these electrical disturbances. On ECG you’d expect early tall, peaked T waves, then PR prolongation and QRS widening as levels rise, potentially progressing to life-threatening rhythms like ventricular fibrillation or asystole. Other signs like hypotension can occur with severe arrhythmias, but rash and nausea are not characteristic features of hyperkalemia.