The nurse is caring for a patient in the failure stage of acute kidney injury based on the RIFLE criteria. Which of the following interventions should the nurse prioritize at this stage?

A. Administer IV potassium to correct hypokalemia: During the failure stage of acute kidney injury (AKI), hyperkalemia is more common than hypokalemia due to impaired renal excretion. Administering IV potassium without careful monitoring can precipitate life-threatening cardiac arrhythmias. Electrolyte management must be guided by laboratory values. B. Prepare for hemodialysis to manage fluid and electrolyte imbalances: The failure stage of AKI is characterized by severe reduction in glomerular filtration rate, oliguria or anuria, and accumulation of toxins, electrolytes, and fluid. Hemodialysis provides rapid removal of excess potassium, urea, and fluid, which is critical to preventing complications such as pulmonary edema, hyperkalemia-induced arrhythmias, and severe acidosis. C. Begin fluid restriction to prevent overload: Fluid restriction may be indicated, especially in oliguric or anuric patients, but it is not sufficient as the primary intervention in the failure stage. Restricting fluid alone does not correct severe electrolyte disturbances or remove accumulated toxins. It is supportive, whereas renal replacement therapy addresses the derangements. D. Encourage oral intake and high protein to support kidney function: High-protein intake may worsen azotemia in AKI because protein metabolism generates nitrogenous waste that the failing kidneys cannot excrete efficiently. Oral intake is encouraged only if not contraindicated, but promoting protein-heavy intake is not a priority in the failure stage.