Final answer:
Hyperkalemia is the finding that should be identified as a manifestation of chronic glomerulonephritis due to the kidneys' reduced ability to excrete potassium.
Step-by-step explanation:
A nurse caring for a patient with chronic glomerulonephritis and oliguria should identify hyperkalemia as a manifestation of chronic glomerulonephritis. This is because in the presence of kidney dysfunction, such as chronic glomerulonephritis, the kidneys are less capable of excreting potassium, leading to increased levels of potassium in the blood. Other common issues associated with kidney malfunction include abnormal fluid levels, acidosis, and over time, anemia can develop due to a decrease in renal production of erythropoietin. However, hyperkalemia is one of the primary findings associated with the reduced function of the kidneys seen in chronic glomerulonephritis.