Which client has the greatest risk of severe hyperkalemia af… | MyMerci
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Medication AdministrationPPT
Question
Which client has the greatest risk of severe hyperkalemia after succinylcholine?
1A client with an uncomplicated ankle sprain sustained two hours ago
2A client with seasonal allergic rhinitis taking an oral antihistamine
3A client with quadriplegia six weeks after a cervical spinal cord injury✓ Correct answer
4A client with controlled hypertension taking a thiazide diuretic
Explanation
A client several weeks after a cervical spinal cord injury has extensive skeletal-muscle denervation and is at high risk for a dangerous potassium surge after succinylcholine. The drug is contraindicated after the acute phase of major burns, multiple trauma, extensive denervation, or upper motor neuron injury because severe hyperkalemia can cause cardiac arrest. The other conditions do not create the same receptor upregulation risk.
Clinical reasoning Denervation increases extrajunctional acetylcholine receptors across skeletal muscle. Succinylcholine depolarizes these receptors and can release enough potassium to trigger lethal dysrhythmias.
Decision rule Before succinylcholine, screen for prior burns, denervation, prolonged immobility, neuromuscular disease, major trauma, and baseline hyperkalemia.
Clinical scenario
Scenario The emergency team is preparing rapid-sequence intubation and is screening for conditions that increase the risk of succinylcholine-induced hyperkalemia.
Key concepts
Depolarizing neuromuscular blocker — A paralytic agent such as succinylcholine that activates and then desensitizes nicotinic acetylcholine receptors.
Denervation hyperkalemia — A dangerous potassium rise caused by widespread receptor upregulation after loss of normal nerve input to muscle.
Non-depolarizing NMBA — Rocuronium, vecuronium, cisatracurium; longer onset/duration than succinylcholine.