A 37-yr-old female patient is hospitalized with acute kidney injury (AKI). Which information will be most useful to the nurse in evaluating improvement in kidney function?

A. Urine volume: Monitoring urine output provides a rough estimate of kidney function and fluid balance. However, urine volume alone may be misleading in AKI, as patients can have non-oliguric AKI with normal or high urine output despite poor filtration, making it insufficient to evaluate true improvement in kidney function. B. Blood urea nitrogen (BUN) level: BUN reflects nitrogenous waste accumulation and can indicate impaired renal function. However, it is influenced by factors such as dehydration, high-protein diet, and catabolism, limiting its reliability as the sole marker of kidney recovery. C. Glomerular filtration rate (GFR): GFR directly measures the kidneys’ ability to filter blood and excrete waste. An increasing GFR indicates improving renal function, making it the most accurate and useful parameter to assess recovery from AKI. Trends in GFR provide a comprehensive picture of kidney performance beyond urine output or single lab values. D. Potassium level: Hyperkalemia is a common complication of AKI, reflecting impaired excretion. While potassium monitoring is critical for patient safety, changes in potassium alone do not reliably indicate overall improvement in kidney function, as levels can be influenced by medications, diet, and cellular shifts