Renal Ultrasound Preparation Hydration

A 54-year-old patient with a history of chronic kidney disease (CKD) is scheduled to undergo a renal ultrasound to assess renal function. Prior to the ultrasound, the nurse must educate the patient about the preparation required for the test. One crucial aspect of the preparation is to ensure that the patient has adequate hydration. The nurse explains that the patient should drink at least ____ liters of water in the 24 hours before the test to ensure the kidneys can be visualized effectively.