A nurse is reviewing the laboratory test results from a client who has prerenal acute kidney injury (AKI). Which of the following electrolyte imbalances should the nurse expect?

Choice A rationale Hypercalcemia is not a typical finding in prerenal acute kidney injury. In most forms of renal failure, calcium levels tend to be low because the kidneys are unable to activate vitamin D and phosphorus levels rise, which inversely affects calcium. While some specific conditions like malignancy can cause high calcium, it is not the expected finding for a patient with prerenal injury caused by decreased blood flow to the kidneys. Normal calcium levels are 8.5 to 10.5 mg/dL. Choice B rationale Hypokalemia is generally not expected in acute kidney injury. Most patients with kidney injury develop hyperkalemia because the kidneys are the primary route for potassium excretion. When the glomerular filtration rate drops in prerenal AKI, potassium begins to accumulate in the blood, which can lead to dangerous cardiac arrhythmias. Normal potassium levels range from 3.5 to 5.0 mEq/L. Hypokalemia would only occur if there were excessive losses through vomiting, diarrhea, or specific diuretic use during the injury. Choice C rationale Hypophosphatemia is uncommon in acute kidney injury. The kidneys are responsible for excreting phosphorus, so when their function is impaired, phosphorus levels in the blood typically rise, leading to hyperphosphatemia. High phosphorus levels are a common complication that nurses must monitor for and manage in patients with any stage of renal impairment. The normal range for serum phosphorus is 3.0 to 4.5 mg/dL. Therefore, expecting low phosphorus in a patient with prerenal AKI would be incorrect. Choice D rationale Hyponatremia is a common expected finding in prerenal acute kidney injury. In prerenal states, the body often retains water in an attempt to restore circulating volume, which can dilute the serum sodium concentration. Additionally, the impaired ability of the kidneys to manage electrolytes often leads to sodium imbalances. The normal range for serum sodium is 135 to 145 mEq/L. Monitoring for low sodium is essential as it can cause neurological symptoms like confusion, lethargy, or seizures in severe cases.