Which sign is most consistent with hyperkalemia?

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

Answer: (A)

Hyperkalemia most strongly disrupts the heart’s electrical activity, so cardiac dysrhythmias are the sign most consistent with it. When potassium levels rise, extracellular K+ reduces the gradient across cardiac cell membranes, making the resting membrane potential less negative. This alters conduction and automaticity, setting the stage for various arrhythmias. In practice, you’ll see electrocardiographic changes such as peaked T waves and eventually widened QRS, potentially progressing to a sine-wave pattern and dangerous bradyarrhythmias. Clinically, patients may develop reduced cardiac output and hypotension as a result of these rhythm disturbances, but the hallmark association is rhythm abnormalities. Rash and nausea are not characteristic signs of hyperkalemia.