An adult client who is admitted to the mental health unit for treatment of bipolar disorder has a slightly slurred speech pattern and an unsteady gait. Which assessment finding is most important for the nurse to report to the health care provider?Reference RangeBlood alcohol level [Reference Range: 0 to 10.9 mmol/L (0% to 0.05%)]Lithium [Reference Range: 0.8 to 1.2 mEq/L or 0.8 to 1.2 mmol/L]

Choice A: Blood alcohol level of 0.09% (90 mmol/L) is not the most important finding for the nurse to report, as this is within the reference range and does not indicate alcohol intoxication or withdrawal, which can affect the client's mental status and mood stability. This is a distractor choice.Choice B: Six hours of sleep in the past three days is not the most important finding for the nurse to report, as this is a common symptom of bipolar disorder during manic episodes and does not require immediate intervention by the health care provider. This is another distractor choice.Choice C: Serum lithium level of 1.6 mEq/L (1.6 mmol/L) is the most important finding for the nurse to report, as this indicates lithium toxicity, which can cause neurological and renal impairment and potentially fatal complications such as seizures, coma, and cardiac dysrhythmias. Therefore, this is the correct choice.Choice D: Weight loss of 10 pounds (4.5 kg) in past month is not the most important finding for the nurse to report, as this may be related to decreased appetite or increased activity during manic episodes and does not pose an immediate threat to the client's health or safety. This is another distractor choice.