19th February 2025

A 21-year-old woman presents to the emergency department with flank pain, paraesthesia and palpitations

A 21-year-old woman presents to the emergency department with flank pain, paraesthesia and palpitations. She has recently commenced treatment for acute myeloid leukaemia.

You arrange blood tests that show: Na 146 mmol/L (133-146 mmol/L), K 6.2 mmol/L (3.5-5.3 mmol/L), Creatinine 130 µmol/L (45-104 µmol/L), Urea 5.6 mmol (2.5-7.8 mmol/L), PO4 1.9 mmol/L (0.80-1.50 mmol/L), Ca 1.45 mmol/L (2.20-2.60 mmol/L).

Her ECG shows tall T waves, with QRS complex of 125 ms.

What is the most appropriate first step in management?

Select the SINGLE most appropriate option from the list below. Select ONE option only.