Why should Succinylcholine (Succs) be avoided in a patient with hyperkalemia?

From the Guidelines

Succinylcholine should be avoided in patients with hyperkalemia because it can cause a dangerous increase in serum potassium levels, potentially leading to cardiac arrhythmias and cardiac arrest. When administered, succinylcholine causes widespread depolarization of the muscle cell membrane, releasing potassium from inside muscle cells into the bloodstream. In normal patients, this typically raises serum potassium by 0.5-1.0 mEq/L, which is usually well-tolerated. However, in patients who already have elevated potassium levels, this additional increase can push them into a critical range (>6.5-7.0 mEq/L) where serious cardiac complications may occur. Some key points to consider when managing hyperkalemic patients include:

• Avoiding the use of succinylcholine, as recommended in guidelines for managing certain patient populations, such as those with immobilization or neuromuscular diseases 1
• Considering alternative neuromuscular blocking agents such as rocuronium or vecuronium for rapid sequence intubation, as they do not cause potassium release
• Treating hyperkalemia before proceeding with airway management, if time permits, using therapies such as insulin with glucose, calcium gluconate, or sodium bicarbonate to lower potassium levels. Key considerations for airway management in hyperkalemic patients include:
• The potential for succinylcholine to exacerbate hyperkalemia and increase the risk of cardiac complications
• The importance of selecting alternative neuromuscular blocking agents that do not cause potassium release
• The need to prioritize treatment of hyperkalemia before proceeding with airway management, if possible.

From the FDA Drug Label

Succinylcholine should be administered with GREAT CAUTION to patients suffering from electrolyte abnormalities and those who may have massive digitalis toxicity, because in these circumstances succinylcholine may induce serious cardiac arrhythmias or cardiac arrest due to hyperkalemia Patients with chronic abdominal infection, subarachnoid hemorrhage, or conditions causing degeneration of central and peripheral nervous systems should receive succinylcholine with GREAT CAUTION because of the potential for developing severe hyperkalemia Succinylcholine is contraindicated in patients after the acute phase of injury following major burns, multiple trauma, extensive denervation of skeletal muscle, or upper motor neuron injury, because succinylcholine administered to such individuals may result in severe hyperkalemia which may result in cardiac arrest

Succinylcholine (Succs) should be avoided in a patient with hyperkalemia because it may induce serious cardiac arrhythmias or cardiac arrest due to further increases in potassium levels 22.

From the Research

Reasons to Avoid Succinylcholine in Hyperkalemia

• Succinylcholine can increase potassium concentrations, which may be problematic in patients with hyperkalemia 3.
• Although one study suggests that succinylcholine may be safe in patients with moderate hyperkalemia, the risk of dysrhythmias or other major morbidity cannot be entirely ruled out 4.
• The risk of hyperkalemia after succinylcholine injection is strongly associated with the length of ICU stay, with a higher risk after 16 days 5.
• Hyperkalemia is a condition that can lead to fatal dysrhythmias and muscular dysfunction, and certain medications like succinylcholine can exacerbate this condition 6.

Alternative Considerations

• Other neuromuscular blocking drugs like rocuronium may be safer alternatives to succinylcholine in patients with hyperkalemia, as they do not increase potassium concentrations 3.
• The treatment of hyperkalemia typically involves the use of potassium-lowering agents, such as sodium polystyrene sulfonate, patiromer, and sodium zirconium cyclosilicate, which can help reduce serum potassium levels 6, 7.
• Clinicians must carefully evaluate the risks and benefits of using succinylcholine in patients with hyperkalemia and consider alternative treatments to minimize the risk of adverse effects 4, 3, 5.