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PUID: 63 || PLAB 2 Mock 3 :: Emergency3: Lithium Toxicity Bipolar Talk To Daughter


Summary:

This scenario focuses on identifying and managing lithium toxicity, a potentially life-threatening condition presenting with neurological and gastrointestinal symptoms. Early recognition and prompt management are crucial to prevent complications like renal failure.



Key Points


Core Condition: Lithium Toxicity

  • Narrow therapeutic index → high risk of toxicity

  • Can occur due to overdose, dehydration, renal impairment, or poor monitoring


Neurological Features

  • Fine tremors (early, therapeutic levels)

  • Coarse tremors (toxicity)

  • Confusion, reduced consciousness

  • Poor coordination / ataxia


Gastrointestinal Features (Earliest & Most Common)

  • Nausea

  • Vomiting

  • Diarrhoea


Renal & Endocrine Effects

  • Diabetes insipidus → polyuria, dehydration

  • Hypothyroidism / hyperthyroidism (less acute relevance but important)


Medication & Monitoring

  • Lithium used in bipolar disorder

  • Requires frequent serum monitoring:

    • Weekly initially (first 3 months)

  • Assess:

    • Dose, adherence, last level

    • Follow-up compliance



Important Considerations

  • This is a medical emergency → requires admission

  • Symptoms may mimic other conditions (e.g., Parkinson’s)

  • Always ask for:

    • Urine output (for DI)

    • Associated symptoms (GI + neuro)

  • Consider triggers:

    • Infection

    • Dehydration

  • Social factors:

    • Living alone → poor adherence risk



Diagnostic Approach


Step-by-Step

  1. Focused History

    • Symptom onset (tremors, confusion)

    • GI symptoms (vomiting, diarrhoea)

    • Urine output (DI)

    • Medication history (dose, adherence, monitoring)

    • Social support

  2. Examination

    • Vitals (HR, BP, RR, SpO₂, Temp)

    • Neurological exam (tremor, coordination)

  3. Investigations

    • Serum lithium level (confirm diagnosis)

    • U&E (renal function)

    • TFTs

    • ECG (if severe)

  4. Clinical Reasoning

    • Use provisional diagnosis:

      • “Symptoms are suggestive of lithium toxicity”



Management


Immediate Management

  • STOP lithium immediately

  • Admit to hospital

  • IV fluids (mainstay) → enhance excretion


Escalation

  • If no improvement / severe toxicity:

    • Hemodialysis (definitive removal)


Specialist Involvement

  • Renal team

  • Psychiatry team


Additional Measures

  • Contact GP → check monitoring history

  • Address adherence issues


Safety Netting

  • Educate about:

    • Early symptoms

    • Importance of monitoring



Communication Skills

  • Avoid over-explaining → be concise and structured

  • Use provisional language:

    • “This may be due to high lithium levels”

  • Break consultation into sections (signposting)

  • Show empathy naturally (avoid stock phrases)

  • Prioritise main management first, then extras (e.g., social support)



Ethical Considerations

  • Follow principles from :

    • Patient safety is priority

    • Clear communication and shared decision-making

    • Work within competence and escalate appropriately

  • Maintain confidentiality and professionalism



Additional Resources

  • GMC: Good Medical Practice

  • PLAB 2 Examiner Top Tips

  • GMC Results Interpretation Guide

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