Which of the following does the nurse understand are the cardinal features of acute kidney injury?

Rationale: A. Decreased glomerular filtration is a key underlying mechanism in acute kidney injury (AKI) but alone is not considered a cardinal feature. It contributes to the manifestations but is more of a pathophysiologic change rather than a defining clinical feature. B. Increase in urine output is incorrect because AKI typically causes oliguria (decreased urine output), although some patients may develop non-oliguric AKI. Increased urine output is not a primary hallmark. C. Uremia and fatigue are common symptoms of AKI but are consequences of impaired kidney function rather than the cardinal features that define AKI. D. Azotemia and oliguria are correct because azotemia (elevated blood urea nitrogen and creatinine) and oliguria (reduced urine output, usually <0.5 mL/kg/hr) are the primary clinical and laboratory features that define acute kidney injury. These indicators are used to diagnose and stage AKI and guide management.