Which anesthetic is associated with hyperkalemia leading to arrhythmia?

• A. Halothane
• B. Etomidate
• C. Propofol
• D. Succinylcholine

Answer: (D)

Succinylcholine is unique among anesthetics as it acts as a depolarizing muscle relaxant. One of its primary effects is to cause transient muscle fasciculations followed by paralysis. This depolarization can lead to a release of potassium from the intracellular space into the bloodstream, potentially resulting in elevated serum potassium levels, a condition known as hyperkalemia.

Hyperkalemia can increase the risk of cardiac arrhythmias because it alters the normal action potentials in cardiac tissues. Elevated potassium levels can lead to changes in resting membrane potential and affect repolarization, making the heart more prone to arrhythmias. This is particularly concerning in patients with pre-existing conditions like renal failure, burns, or neuromuscular diseases, where potassium levels may already be compromised.

While other anesthetics might have different side effects, they do not have the same direct link to causing hyperkalemia. Halothane and etomidate generally do not cause significant shifts in potassium levels, and propofol is also not associated with this effect. Therefore, succinylcholine is the anesthetic most closely linked to hyperkalemia and the associated risk of arrhythmia.