Which neuromuscular blocker is contraindicated in patients with hyperkalemia?

Succinylcholine is contraindicated in patients with hyperkalemia due to its mechanism of action and the physiological effects it produces. This neuromuscular blocker is a depolarizing agent that mimics acetylcholine, binding to nicotinic receptors at the neuromuscular junction and causing continuous depolarization of the motor end plate. This results in a transient contraction followed by muscle paralysis.

The key issue with succinylcholine arises during the depolarization phase, when it can lead to an increase in potassium efflux from the intracellular space to the extracellular fluid. In patients with hyperkalemia, who already have elevated serum potassium levels, this additional release of potassium can lead to severe cardiac complications, including potentially fatal arrhythmias or cardiac arrest.

In contrast, other neuromuscular blockers like vecuronium, pancuronium, and atracurium do not share this property and are more safely used in the context of elevated potassium levels. These non-depolarizing agents do not cause a release of potassium; rather, they function by blocking neuromuscular transmission without the initial depolarization that succinylcholine causes. Therefore, the use of succinylcholine in patients with hyperkalemia poses