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PUID: 42 || PLAB 2 Mock 3 :: Emergency3: Lithium Toxicity Bipolar Talk to Daughter



Summary:

This case involves an elderly male patient presenting with symptoms such as tremors, confusion, vomiting, and diarrhea. Upon further history, it is revealed that the patient has been on lithium therapy for bipolar disorder. The primary diagnosis is lithium toxicity, a potentially life-threatening condition requiring immediate recognition and hospital management.



Key Points:


Neurology/General Medicine

  • Patient exhibited tremors, which were coarse (suggestive of toxicity).

  • Confusion and drowsiness were noted, indicating CNS involvement.

  • History of jerky movements and unsteadiness on feet.


Gastrointestinal

  • Vomiting and diarrhea contributed to dehydration, worsening lithium toxicity.


Pharmacology

  • Lithium toxicity triad: GI symptoms, confusion, tremors.

  • Fine tremors can occur at normal levels, coarse tremors are typical in toxicity.

  • Important mnemonic: T-H-I-U-M

    • T: Tremors

    • H: Hypothyroidism

    • I: Increased parathyroidism

    • U: Urine output (diabetes insipidus)

    • M: Mental status changes


History

  • Lithium use for bipolar disorder, a critical clue.

  • No recent lithium levels or monitoring indicated.

  • Patient lives alone; recent bereavement (wife died), raising concerns for adherence and support.


Important Considerations:

  • Always follow up on unusual findings like lithium use.

  • Lithium toxicity can present subtly—be alert to GI, neurological, and renal symptoms.

  • Elderly patients are at higher risk due to altered pharmacokinetics.

  • Never give a diagnosis if unsure—acknowledge limitations and escalate to seniors.


Diagnostic Approach:

  1. Thorough History Taking

    • Focus on medication use, especially lithium: dosage, adherence, monitoring.

    • Assess for symptoms: tremors, confusion, diarrhea, vomiting.

  2. Focused Physical Examination

    • Neurological exam (tremors, confusion).

    • Hydration status and vital signs.

    • Check urine output.

  3. Investigations

    • Serum lithium levels.

    • Renal function tests.

    • Electrolytes.

    • ECG if cardiac involvement suspected.


Management:

  • Immediate Actions

    • Discontinue lithium.

    • Initiate IV fluids to enhance excretion.

    • Admit to hospital—this is not a discharge case.

  • Further Management

    • Consult nephrology and psychiatry.

    • Consider hemodialysis if unresponsive to hydration.

  • Monitoring

    • Regular lithium levels and renal function.

    • Monitor fluid and electrolyte balance.

  • Preventive Measures

    • Social care involvement (e.g., home visits, meal services).

    • Educate on regular follow-up and toxicity signs.

    • Provide information leaflets and safety netting.


Communication Skills:

  • Show empathy, especially given recent bereavement.

  • Use clear, jargon-free language.

  • Actively listen—avoid rehearsed or stock phrases.

  • Provide reassurance with honesty; explain next steps clearly.

  • Signpost and summarize appropriately.


Ethical Considerations:

  • Admit when unsure: Better to say “I need to consult a senior” than give incorrect information.

  • Consent and Capacity: Ensure patient or carer understands management.

  • Professionalism: Maintain honesty and transparency per GMC guidance.


Additional Resources:

  • NICE guidelines on Bipolar Disorder and Lithium Monitoring.

  • GMC’s “Good Medical Practice”.

  • PLAB 2 Examiner Tips: Focus on task relevance, avoid over-promising, and show logical clinical reasoning.

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