Final answer:
Oliguria is a clinical manifestation of acute kidney injury characterized by a decrease in urine output.
Step-by-step explanation:
Oliguria is a clinical manifestation of acute kidney injury. Oliguria is defined as an abnormally small amount of urine, often due to shock or kidney damage. It is characterized by a decrease in urine output, usually less than 400 ml per day in adults or less than 1 ml/kg/h in infants and children.