Final answer:
The top priorities are to halt lithium intake and perform a serum lithium level test due to potential toxicity, with immediate collaboration with a healthcare provider being essential. the correct option is c. Instruct the patient not to take any more lithium until directed by the health care provider.
Step-by-step explanation:
The priority nursing interventions for a patient with symptoms of nausea, vomiting, and unsteady gait after playing soccer on a hot day and taking lithium are: c. Instruct the patient not to take any more lithium until directed by the health care provider, and d. Collaborate with the health care provider about drawing a serum lithium level immediately. These symptoms are suggestive of lithium toxicity, which can be exacerbated by dehydration from physical exertion and heat. Immediate medical assessment is crucial to prevent the progression of toxicity.
Administering an antiemetic is not the priority as the symptoms could be due to toxicity. Increasing the lithium dose would be contraindicated since the patient is exhibiting signs of toxicity. Completing an AIMS assessment is not immediately necessary, as tremors and unsteady gait might be directly related to lithium levels and possible toxicity, which needs to be verified with a serum lithium level test first.