The nurse is aware that the following laboratory values support a diagnosis of pyelonephritis?
Correct Answer: C
Rationale: Pyelonephritis is a bacterial infection of the kidney. One of the key indicators of pyelonephritis is the presence of pyuria, which refers to white blood cells in the urine. White blood cells in the urine suggest inflammation and infection in the urinary tract, particularly in the kidneys. Therefore, the presence of pyuria supports a diagnosis of pyelonephritis. Myoglobinuria (choice A) is the presence of myoglobin in the urine and is associated with muscle breakdown, not specifically with pyelonephritis. Ketonuria (choice B) refers to the presence of ketones in the urine and may be seen in conditions such as diabetic ketoacidosis. A low white blood cell count (choice D) is not typically associated with pyelonephritis, as an infection would generally result in an elevated white blood cell count in response to the infection.