Renal, Urology and Electrolytesmiddle twist
A 68-year-old man with chronic kidney disease is admitted with pneumonia and has received intravenous fluids, calcium gluconate and insulin with glucose for a serum potassium concentration of 7.1 mmol/L (3.5–5.2). His potassium is now 6.9 mmol/L, the urine output has been 40 mL over the past 6 hours, and the electrocardiogram still shows broad QRS complexes. Which one of the following is the most appropriate next step?