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Hyperkalemia with ECG changes — USMLE Step 3 MCQ

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HardEmergency MedicineHyperkalemia with ECG changesUSMLE Step 3

A patient with CKD has potassium 7.1 mEq/L, peaked T waves and QRS widening. IV calcium has just been administered. Which therapy should follow while definitive potassium removal is arranged?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: B — Give regular insulin with dextrose and monitor glucose closely

The best answer is “Give regular insulin with dextrose and monitor glucose closely”. After IV calcium stabilizes the cardiac membrane, insulin with dextrose rapidly shifts potassium intracellularly while definitive elimination is arranged. Sodium polystyrene is too slow and unreliable as sole emergency therapy. Thrombolysis, simply withholding RAAS drugs, and dietary counseling do not treat the immediate life-threatening hyperkalemia.

Reference: American Heart Association, Adult Advanced Cardiovascular Life Support: https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines