A client receiving maintenance lithium therapy has no toxicity symptoms and a 12-hour trough level of 0.8 mEq/L. Which action should the nurse take?
1Hold lithium and prepare for hemodialysis because the level is severely toxic.
2Give an extra dose because the level is below the maintenance range.
3Restrict sodium and fluids to increase the medication concentration.
4Continue the prescribed dose and maintain routine clinical and laboratory monitoring.✓ Correct answer
Explanation
A 12-hour trough lithium concentration of 0.8 mEq/L is within the usual long-term maintenance range of 0.6 to 1.2 mEq/L. In an asymptomatic client, the nurse should continue the prescribed regimen and ongoing monitoring. Dehydration and sodium restriction can raise lithium levels. Extra dosing is unsafe, while hemodialysis is reserved for serious toxicity based on symptoms, concentration, and clinical context.
Clinical reasoning Lithium interpretation depends on accurate sampling time and the client's symptoms. A level drawn immediately before the next dose, about 8 to 12 hours after the prior dose, is compared with the prescribed target.
Decision rule An asymptomatic maintenance client with a properly timed level of 0.8 mEq/L continues the regimen while maintaining stable sodium and fluid intake and scheduled monitoring.
Lithium trough level — A serum sample obtained immediately before the next dose, approximately 8 to 12 hours after the previous dose, for consistent interpretation.
Lithium maintenance range — A usual long-term serum target of 0.6 to 1.2 mEq/L, interpreted together with symptoms, renal function, and the prescribed plan.
Narrow therapeutic index — Small changes in renal clearance, sodium, hydration, or interacting drugs can push lithium toward toxicity.