A 55-year-old man on furosemide presents with muscle weakness and cramps. K⁺ is 2.5 mmol/L. Mg²⁺ is 0.5 mmol/L. ECG shows prominent U waves and

Question

A 55-year-old man on furosemide presents with muscle weakness and cramps. K⁺ is 2.5 mmol/L. Mg²⁺ is 0.5 mmol/L. ECG shows prominent U waves and flattened T waves. He is haemodynamically stable with no arrhythmias. What is the most appropriate replacement strategy?

Accepted Answer

IV magnesium sulfate 10 mmol over 1 hour then oral Mg replacement, PLUS IV/oral KCl

Answer

IV potassium chloride 40 mmol in 1 L NaCl over 4 hours

Answer

IV potassium chloride 40 mmol over 1 hour via central line

Answer

Oral magnesium oxide alone

Answer

Oral potassium chloride (Slow-K) alone

Hypokalaemia with Hypomagnesaemia — RACP Adult Medicine MCQ

A 55-year-old man on furosemide presents with muscle weakness and cramps. K⁺ is 2.5 mmol/L. Mg²⁺ is 0.5 mmol/L. ECG shows prominent U waves and flattened T waves. He is haemodynamically stable with no arrhythmias. What is the most appropriate replacement strategy?