What is a major contraindication for using Succinylcholine?

Succinylcholine is a neuromuscular blocker commonly used for rapid sequence intubation, but it comes with specific contraindications due to its pharmacological effects. One major contraindication is in patients with burns that have occurred more than 24 hours prior to administration.

The rationale behind this contraindication lies in the drug's mechanism of action and the physiological responses following severe burns. After extended periods of injury, especially from severe burns, there is often a significant upregulation of extrajunctional acetylcholine receptors at the neuromuscular junction. When succinylcholine is administered to a patient with such conditions, it can lead to hyperkalemia due to an excessive release of potassium from the intracellular space as the drug binds to and activates these extra receptors. This can result in life-threatening cardiac arrhythmias.

Therefore, using succinylcholine on patients with burns greater than 24 hours can pose serious risks, emphasizing the importance of recognizing and adhering to contraindications in practice.