A premature neonate at 28 weeks gestation develops oliguria, rising creatinine, and metabolic acidosis on day 3. The urine output is 0.3 mL/kg/hr despite adequate fluid resuscitation. Serum potassium is 6.8 mEq/L with peaked T waves on ECG. What is the FIRST priority in management?

• A Furosemide 1 mg/kg IV to increase urine output
• B Calcium gluconate 10% 1 mL/kg IV to stabilise the cardiac membrane ✓
• C Sodium bicarbonate to correct acidosis and shift potassium intracellularly
• D Exchange transfusion to remove potassium

Explanation

When hyperkalaemia produces ECG changes (peaked T waves, wide QRS), the first and most urgent step is IV calcium gluconate 10% (0.5–1 mL/kg over 5–10 minutes) to stabilise the myocardial membrane and prevent fatal arrhythmias. This does not lower serum potassium but buys time for subsequent measures. After membrane stabilisation, insulin + dextrose, sodium bicarbonate, salbutamol nebulisation, and kayexalate/resonium are used to shift or remove potassium. Furosemide will not work if acute kidney injury has caused oliguria from tubular injury.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.