MSRA-2315

MSRA-2315

A 65-year-old man presents to the emergency department with a 12-day history of muscle cramping and fatigue. His blood tests and ECG are as follows:
– Na+ 140 mmol/L (135 – 145)
– K+ 3.7 mmol/L (3.5 – 5.0)
– Bicarbonate 28 mmol/L (22 – 29)
– Urea 6.2 mmol/L (2.0 – 7.0)
– Creatinine 95 µmol/L (55 – 120)
– Calcium 1.7 mmol/L (2.1-2.6)
– Phosphate 1.3 mmol/L (0.8-1.4)
– Magnesium 0.62 mmol/L (0.7-1.0)

The patient’s ECG shows a regular sinus rhythm with a rate of 72 BPM and a QTc of 480 ms. What is the most appropriate next step in management?