Hyperkalaemia in AKI — FRCA Final MCQ

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EasyIntensive Care MedicineHyperkalaemia in AKIFRCA Final

A 55-year-old man (ASA III) develops acute kidney injury in ICU. His potassium is 5.5 mmol/L and rising. He is on an ACE inhibitor. Which electrolyte disturbance is MOST commonly seen in AKI?

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Correct answer: C — Hyperkalaemia

Hyperkalaemia is the most dangerous and common electrolyte disturbance in AKI. Potassium is normally excreted by the kidneys; reduced GFR leads to potassium accumulation. ACE inhibitors and ARBs worsen hyperkalaemia by reducing aldosterone-mediated potassium excretion. Other electrolyte disturbances in AKI include: hyperphosphataemia, hypocalcaemia, metabolic acidosis, and hypermagnesaemia. ECG monitoring is essential; hyperkalaemia causes peaked T waves, widened QRS, and ultimately VF/asystole.

Reference: NICE – 2019 – NG148 AKI; RCOA – 2023 – ICM curriculum: renal physiology