Hyperkalemia: Why Calcium Is the FIRST Drug (and Doesn't Lower Potassium) | NCLEX

When potassium climbs high enough to threaten the heart, the first drug doesn't lower the potassium at all — it's calcium. Here's why that makes complete sense, built from one idea all the way to the questions you'll see on the NCLEX. In this deep dive you'll understand (not memorize): • How potassium sets the heart cell's resting voltage (≈ −90 mV) • Why high potassium can make cardiac conduction FAIL — not simply race • The hyperkalemia ECG, step by step: peaked T → PR prolongation / P flattening → wide QRS → sine wave → VF/asystole • Treatment in the exact order the exam tests it: STABILIZE (calcium) → SHIFT (insulin + glucose, albuterol) → REMOVE (binders, loop diuretics, dialysis) • Why calcium comes first when the ECG changes — and why it doesn't change the potassium number Chapters 0:00 The calcium paradox 0:21 The one idea 1:05 Inside the cell: the −90 mV resting line 3:05 Raise the potassium: why the signal fails 5:22 On the monitor: the hyperkalemia ECG 7:47 Treatment: stabilize, shift, remove 10:27 On the exam 11:31 Rebuild the chain ▶ Subscribe for clear NCLEX mechanism breakdowns — one topic at a time. Educational content for nursing students; not medical advice. Always follow current guidelines and your facility's protocols.