A 9-year-old child in the PICU is on mechanical ventilation for septic shock. He has oliguric AKI. Serum potassium is 6.8 mEq/L with peaked T waves on ECG. The immediate first step in management of this hyperkalemia is:

• A Sodium polystyrene sulfonate enema — removes potassium from body
• B 10% calcium gluconate IV — membrane stabilization ✓
• C Salbutamol nebulization — shifts K into cells
• D Sodium bicarbonate IV — drives K into cells

Explanation

When ECG changes (peaked T waves, widened QRS) indicate cardiac toxicity from hyperkalemia, the immediate priority is membrane stabilization with 10% calcium gluconate IV (or calcium chloride in arrest settings). Calcium does not lower serum potassium but directly antagonizes cardiac membrane effects within minutes, preventing fatal arrhythmias. Potassium-lowering measures (salbutamol, bicarbonate, kayexalate, dialysis) are important but take longer and do not address immediate cardiac risk.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.