Elevated CK as Contraindication for Succs?


Forum Lieutenant
The protocol for Succs. lists the following Contraindications:

- Hypersensivity
- Family Hx Manignant Hyperthermia
- Known or Suspected Hyperkalemia
- Myopathies assoc. with Elevated CK

The first three make sense and are discussed in various airway, pharm., and anaesthesia texts I have. However, I haven’t found a clear reference for why elevated CK is a direct contraindication. Given elevated CK is indicative of muscle damage, we can assume there will be elevated K+ serum levels too, but this seems like a very round-about way of getting back to concern re: Hyperkalemia which is already listed as a contraindication and -depending on the source you read- may or may not be as significant a concern as some are lead to believe.

Is there a direct pathway/link between CK and Succs I’m not aware of?

- C


Forum Chief
I saw this a few months back when I was putting together a lecture on RSI for my agency. That and patients with MG were too I hadn't heard much of, but there's mentions of in literature.


Forum Lieutenant
That and patients with MG were too...
From Katzung — Basic and Clinical Pharmacology
Section V — Ch. 27: Skeletal Muscle Relaxants (p. 475)

“At least two additional types of acetylcholine receptors are found within the neuromuscular apparatus. One type is located on the presynaptic motor axon terminus... The second type of receptor is found on the extrajunctional cells and is not normally involved in neuromuscular transmission. However, under certain conditions (e.g., prolonged immobilication, thermal burns), these receptors may proliferate sufficiently to affect subsequent neuromuscular transmission. This proliferation of extrajunctional acetylcholine receptors may be clinically relevant when using depolarizing or nondepolarizing skeletal musclke relaxant drugs...”

From Katzung — Basic and Clinical Pharmacology
Section V — Ch. 27: Skeletal Muscle Relaxants (p. 483)

“Other Adverse Effects of Depolarizing Blockade
A. Hyperkalemia
Patients with burns, nerve damage, or neuromuscular disease, closed head injury, and other trauma may develop a proliferation of extrajunctional acetylcholine receptors. During administration of succinylcholine, potassium is released from muscles, likely due to fasiculations. If the proliferation of extrajunctional receptors is great enough, sufficient potassium may be released to result in cardiac arrest.”

Since Myasthenia Gravis is a neuromuscular disease characterized by the autoimmune destruction of ACh receptors, it stands to reason if there is a ‘proliferation of extrajunctional ACh receptors’ administration of Succinylcholine in this patient population could cause Hyperkalemia.
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Forum Asst. Chief
I would be hesitant giving sux in a patient with a myopathy unless you confidently have a good understanding of the interaction with different myopathies. Some of the congenital myopathies that are linked with RYR1 variants such as Nemaline Rod Myopathy, Central Core Disease, Multicore Myopathy have an increased risk of malignant hyperthermia and its contraindicated. Additionally other myopathies have unpredictable responses to sux leading to hyperkalemia and rhabdo. The thought is anyone with one of the myopathies with a history of elevated CK following exercise, stress, heat etc (or known disorder to cause increase like Duchenne's) should avoid using.