Succinylcholine, when given to patients with renal failure, will increase serum potassium by approximately

Succinylcholine, when given to patients with renal failure, will increase serum potassium by approximately

• A. No increase in [K+]
• B. 0.5 mEq/L
• C. 1.5 mEq/L
• D. Greater than 2.5 mEq/L

Answer: (B)

Succinylcholine causes a transient shift of potassium from inside muscle cells to the extracellular space by depolarizing the motor endplate. In individuals without predisposing conditions, this rise in serum potassium is modest, about 0.5 mEq/L. In renal failure, baseline potassium is often higher, so there’s more room for danger if other factors are present, but the immediate, typical rise from a single dose remains around 0.5 mEq/L. Larger increases (well over 1 mEq/L or more than 2.5 mEq/L) occur when there are upregulated extrajunctional receptors from conditions like denervation or severe burns. Thus, the approximate increase is 0.5 mEq/L.

Succinylcholine causes a transient shift of potassium from inside muscle cells to the extracellular space by depolarizing the motor endplate. In individuals without predisposing conditions, this rise in serum potassium is modest, about 0.5 mEq/L. In renal failure, baseline potassium is often higher, so there’s more room for danger if other factors are present, but the immediate, typical rise from a single dose remains around 0.5 mEq/L. Larger increases (well over 1 mEq/L or more than 2.5 mEq/L) occur when there are upregulated extrajunctional receptors from conditions like denervation or severe burns. Thus, the approximate increase is 0.5 mEq/L.