Report a lithium level above 1.5 mEq/L or any confusion, coarse tremor, ataxia, or seizures immediately.
Before you read
Test yourself first: 5 questions
Question 1 of 5
A client on lithium carbonate for bipolar disorder has a serum lithium level of 2.1 mEq/L. Which assessment finding requires immediate nursing action?
Answer: B. The therapeutic range for lithium is approximately 0.6 to 1.2 mEq/L. A level of 2.1 mEq/L indicates toxicity. Coarse hand tremors, severe diarrhea, vomiting, ataxia, and confusion are signs of lithium toxicity and require holding the drug and notifying the provider.
Question 2 of 5
A nurse is teaching a client beginning lithium therapy. Which instruction is most important for preventing lithium toxicity?
Answer: C. Lithium is reabsorbed in the kidney like sodium. Dehydration or low sodium intake increases lithium reabsorption and can cause toxicity. Clients should maintain consistent sodium intake and adequate fluids (about 2 to 3 liters per day) and avoid sudden changes.
Question 3 of 5
A nurse is preparing to administer medications. For which client should the nurse question giving the scheduled lithium dose?
Answer: B. Lithium should be held and the provider notified when the level is toxic or when conditions promote toxicity. A client with a serum lithium of 1.8 mEq/L plus vomiting, slurred speech, and ataxia shows toxicity, so the dose should be questioned. A level of 0.8 mEq/L with no symptoms is therapeutic and the dose can be given.
Question 4 of 5
A client receiving lithium has developed polyuria and increased thirst. The nurse understands this reflects which effect of lithium on the kidneys?
Answer: B. Lithium can interfere with the kidney's response to antidiuretic hormone, causing nephrogenic diabetes insipidus, which produces polyuria and polydipsia. Renal function should be monitored, and the client should maintain adequate hydration.
Question 5 of 5
A client taking lithium reports new onset of vomiting and diarrhea from a stomach virus. Which instruction is most important for the nurse to give?
Answer: B. Sodium and fluid loss (vomiting, diarrhea, sweating, low-sodium diet) increases lithium reabsorption and can cause toxicity. The client should maintain adequate fluid and salt intake and contact the provider, as a lithium level may be needed. Restricting fluids or sodium would worsen toxicity.
Keep the streak going with more questions like these, each with a full rationale.
What is lithium toxicity?
Because lithium is handled like sodium by the kidneys, dehydration, low sodium intake, and diuretics raise the level and cause toxicity. Early signs are GI upset and fine tremor; severe toxicity causes confusion, seizures, and can be fatal.
Key points to remember
- Therapeutic lithium level is about 0.6-1.2 mEq/L; toxicity begins above 1.5 mEq/L and is severe above 2.0 mEq/L.
- Early/mild toxicity: nausea, vomiting, diarrhea, fine hand tremor, polyuria, and thirst.
- Moderate to severe toxicity: coarse tremor, confusion, ataxia, slurred speech, hyperreflexia, seizures, and dysrhythmias.
- Lithium and sodium compete; low sodium or dehydration raises lithium, while adequate sodium and fluids keep it stable.
- Thiazide diuretics, NSAIDs, ACE inhibitors, and dehydration increase lithium levels.
- There is no antidote; treatment is supportive, with hemodialysis for severe toxicity.
Signs & symptoms
- Early: N/V, tremor, diarrhea
- Late: ataxia, slurred speech, seizures
- Confusion, coarse tremor
Nursing priorities
- Hold the dose and notify the provider for a level above 1.5 mEq/L or signs of toxicity.
- Monitor lithium levels, sodium, renal function, and thyroid as ordered.
- Ensure adequate, consistent fluid intake (about 2-3 L/day) and stable dietary sodium.
- Assess for tremor, GI symptoms, neurologic changes, and dehydration each shift.
- Prepare for supportive care or hemodialysis in severe toxicity.
Labs & values
Patient teaching
- Drink 2-3 liters of fluid daily and keep your salt intake consistent; do not start a low-salt diet.
- Have your lithium blood level checked regularly as scheduled.
- Report vomiting, diarrhea, heavy sweating, coarse tremor, confusion, or unsteady walking.
- Avoid NSAIDs like ibuprofen and tell providers you take lithium before any new prescription.
Red flags: report now
- Report a lithium level above 1.5 mEq/L or any confusion, coarse tremor, ataxia, or seizures immediately.
- Never let the client become dehydrated or start a low-sodium diet or thiazide diuretic without monitoring.
- Vomiting, diarrhea, fever, or heavy sweating can rapidly raise lithium and must be reported.
References
Clinical references for this topic
