What complication is a CKD patient at highest risk for?

• A. Hypernatremia
• B. Hypokalemia
• C. Hyperkalemia
• D. Hypophosphatemia

Answer: (C)

In CKD, the kidneys lose their ability to excrete potassium effectively. As kidney function declines (lower GFR), potassium clearance drops, so serum potassium tends to rise. Metabolic acidosis, common in CKD, also causes potassium to shift from cells into the blood, raising levels further. Medications often used in CKD, such as ACE inhibitors, ARBs, and potassium-sparing diuretics, can worsen this by reducing potassium excretion or increasing intake. This combination makes hyperkalemia the most likely complication. Hypernatremia is less tied to CKD itself and more to water balance, hypokalemia would require loss of potassium (less typical unless specific diuretics or GI losses are present), and CKD typically leads to hyperphosphatemia rather than hypophosphatemia.