Myalgia, Pyrexia and Raised Creatinine

🗒️ Question

A 45 year old man presents to the emergency department with severe muscle pain, weakness and dark-coloured urine. He had been participating in an ultra-marathon two days prior and noticed these symptoms shortly after completing the race.

On examination, he has a fever of 38.5°C, a heart rate of 110 bpm and diffuse muscle tenderness. His past medical history includes hypertension managed with ramipril.

Blood results show the following:

• Creatine kinase (CK): 25,000 U/L (normal: 30-200 U/L)

• Serum creatinine: 221 µmol/L (normal: 64-104 µmol/L)

• Potassium: 5.8 mmol/L (normal: 3.5-5.3 mmol/L)

• Urinalysis: Positive for blood, negative for red blood cells

• Myoglobin: Elevated

What is the most appropriate initial management for this patient?

(A) IV sodium bicarbonate
(B) Haemodialysis
(C) IV isotonic saline
(D) Loop diuretic
(E) IV calcium gluconate