Which sign indicates Acute Kidney Injury (AKI)?

Acute Kidney Injury (AKI) is characterized by a rapid decrease in kidney function, which is commonly reflected in changes in serum creatinine levels. An increased serum creatinine level is a key indicator of impaired kidney function and corresponds to a reduced ability of the kidneys to filter waste products from the blood effectively.

In AKI, serum creatinine levels can rise sharply and quickly, often serving as an important diagnostic marker for clinicians to identify the severity of kidney impairment. Monitoring serum creatinine is crucial in the management of AKI, as it helps guide treatment decisions and assess the recovery of kidney function over time.

In contrast, increased urine output is generally associated with other conditions, not AKI, where urine output typically decreases due to decreased kidney function. Decreased serum creatinine would indicate improved kidney function, which is not consistent with AKI. Additionally, increased physical activity does not directly relate to kidney function assessment and would not be a sign of AKI.

Thus, observing an increased serum creatinine level is a fundamental sign of acute kidney injury that necessitates further evaluation and management.