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Severe Hyperkalaemia — RACP Adult Medicine MCQ

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EasyNephrologySevere HyperkalaemiaRACP Adult Medicine

A 68-year-old man with CKD stage 5 (eGFR 8 mL/min/1.73m²) not yet on dialysis presents with profound weakness. ECG shows tall peaked T waves, absent P waves, and widened QRS progressing to a sine wave pattern. K⁺ is 7.8 mmol/L. What is the most likely electrolyte abnormality causing symptoms?

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Correct answer: E — Hyperkalaemia

Severe hyperkalaemia (K⁺ >6.5 mmol/L) with ECG changes (peaked T waves → absent P waves → widened QRS → sine wave → cardiac arrest) is a medical emergency. Immediate management: IV calcium gluconate 10% (cardiac membrane stabilisation), insulin-glucose (10 units actrapid + 50 mL 50% dextrose), salbutamol nebuliser. Urgent dialysis is required for refractory hyperkalaemia in ESKD.

Reference: eTG Nephrology – 2024 – Hyperkalaemia Emergency; ANZSN Guidelines