Final answer:
The key element in the emergency treatment of serotonin syndrome is supportive care, including sedation and muscle relaxants if necessary.
Step-by-step explanation:
The key element in the emergency treatment of a patient with serotonin syndrome, beyond stopping the offending agent, is supportive care. Supportive care includes measures such as monitoring vital signs, maintaining hydration, and providing symptomatic relief for hyperthermia, agitation, and autonomic instability.
In severe cases, sedation may be necessary to control agitation and manage seizures. Additionally, muscle relaxants may be used to reduce muscular hyperactivity.
It is important to seek medical assistance immediately if serotonin syndrome is suspected, as prompt treatment can help prevent complications.