A nurse is reviewing laboratory results for a client and notes a serum lithium level of 1.6 mEq/L. Which of the following manifestations should the nurse expect the client to report?

A. "Lip smacking and tongue thrusting." These symptoms are more characteristic of tardive dyskinesia, a side effect of long-term antipsychotic use, rather than lithium toxicity. Lithium toxicity primarily affects the gastrointestinal and neurological systems. While movement disorders can occur with severe toxicity, lip smacking and tongue thrusting are not typical early signs. B. "GI discomfort and poor coordination." A lithium level of 1.6 mEq/L falls within the mild to moderate toxicity range. Early signs include nausea, vomiting, diarrhea, and fine hand tremors. Poor coordination, dizziness, and muscle weakness may also be present as lithium begins affecting the central nervous system. Prompt intervention, such as fluid management and dose adjustment, is necessary to prevent progression to severe toxicity. C. "Blurred vision and jerking motor movements." Severe lithium toxicity (levels above 2.0 mEq/L) can cause neurological impairments, including tremors, muscle rigidity, and seizures. However, at a level of 1.6 mEq/L, symptoms are generally milder and include gastrointestinal distress and coordination issues. Blurred vision and significant motor dysfunction are more indicative of advanced toxicity. D. "Fever and fluctuating blood pressure." Autonomic instability, including fever and blood pressure fluctuations, is not a common manifestation of lithium toxicity. These symptoms are more characteristic of conditions such as serotonin syndrome or neuroleptic malignant syndrome. Lithium toxicity primarily presents with gastrointestinal, neurological, and coordination-related symptoms.