The client’s lithium level is 1.8 mEq/L. The first appropriate nursing action is to:

Choice A reason: Observing for toxicity is important, but a lithium level of 1.8 mEq/L, above the therapeutic range (0.6–1.5 mEq/L), requires immediate action. Observation alone delays critical intervention, as symptoms like confusion or ataxia may already be present, necessitating urgent medical evaluation. Choice B reason: Documenting results is necessary but not the first action. A lithium level of 1.8 mEq/L indicates potential toxicity, requiring immediate physician notification to adjust dosing or provide treatment, as delays could worsen neurological or renal complications. Choice C reason: A lithium level of 1.8 mEq/L is above the therapeutic range, indicating early toxicity, which can cause neurological and renal damage. Notifying the physician immediately ensures prompt dose adjustment or discontinuation, preventing progression to severe toxicity, making this the priority action. Choice D reason: Holding the next dose without physician guidance is risky, as abrupt cessation may destabilize mood in bipolar disorder. A level of 1.8 mEq/L requires medical evaluation to determine safe dose adjustments, making physician notification the first step.