A 65-year-old woman is brought to the emergency department by her son. The patient lives alone and works as a librarian. The son became concerned 2 days ago when "she didn't sound right and seemed somewhat confused over the phone." When he arrived at her home this morning, the patient was disoriented and her speech was slurred. Medical history is significant for diabetes mellitus controlled with metformin. The son says that a "mood disorder" runs in the family and that she has taken lithium, escitalopram, and risperidone for the past several years. A month ago, the patient was diagnosed with hypertension and arthritis, and treatment with chlorthalidone and acetaminophen was initiated. She does not use tobacco, alcohol, or illicit drugs. Temperature is 36.1 C (97 F), blood pressure is 150/90 mm Hg, pulse is 52/min, and respirations are 16/min. Physical examination shows coarse hand tremor and an unstable gait. The patient is oriented to person but not to time or place. The patient's lithium level was found to be 4.2 mEq/L (normal:

Question

A 65-year-old woman is brought to the emergency department by her son.  The patient lives alone and works as a librarian.  The son became concerned 2 days ago when "she didn't sound right and seemed somewhat confused over the phone."  When he arrived at her home this morning, the patient was disoriented and her speech was slurred.  Medical history is significant for diabetes mellitus controlled with metformin.  The son says that a "mood disorder" runs in the family and that she has taken lithium, escitalopram, and risperidone for the past several years.  A month ago, the patient was diagnosed with hypertension and arthritis, and treatment with chlorthalidone and acetaminophen was initiated.  She does not use tobacco, alcohol, or illicit drugs.  Temperature is 36.1 C (97 F), blood pressure is 150/90 mm Hg, pulse is 52/min, and respirations are 16/min.  Physical examination shows coarse hand tremor and an unstable gait.  The patient is oriented to person but not to time or place. The patient's lithium level was found to be 4.2 mEq/L (normal: <1.5 mEq/L).  Which of the following is the most effective management strategy?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c055_9f74_8f63_71030a915da8_MD0005_00 Hemodialysis is the most effective method to rapidly remove lithium (a small, charged, non-protein-bound particle). The indications for hemodialysis in lithium toxicity are: Lithium level >4 mEq/L Lithium level of 2.5-4 mEq/L with severe neurologic symptoms or acute kidney injury A rising lithium level despite appropriate volume resuscitation (Choice A) Hydration with isotonic saline increases renal filtration and lithium excretion by the kidneys. All patients with lithium overdose, except those with specific contraindications (eg, decompensated congestive heart failure), should be hydrated with intravenous fluids. However, hydration alone at higher lithium levels is not sufficient. (Choice B) Charcoal does not bind to charged particles like lithium and is not useful in lithium toxicity. Gastrointestinal decontamination in acute poisoning can be performed using a polyethylene glycol solution. (Choice C) Furosemide can cause volume depletion, increase lithium reabsorption in the proximal tubules, and worsen lithium toxicity. (Choice E) Although lithium toxicity may precipitate distal (type 1) renal tubular acidosis, it rarely results in actual metabolic acidosis or the need for sodium bicarbonate infusion. Educational objective: Lithium toxicity presenting with severe neurologic symptoms is an absolute indication for urgent hemodialysis. Other indications for hemodialysis include a lithium level >4 mEq/L or an increasing lithium level despite saline administration. References: Lithium: updated human knowledge using an evidence-based approach: part III: clinical safety. (http://www.ncbi.nlm.nih.gov/pubmed/19453201) Extracorporeal treatment for lithium poisoning: systematic review and recommendations from the EXTRIP Workgroup. (http://www.ncbi.nlm.nih.gov/pubmed/25583292)

A 65-Year-Old Woman Is Brought to the Emergency Department by Her