A 33-year-old patient is hospitalized for treatment of acute…

A 33-yeаr-оld pаtient is hоspitаlized fоr treatment of acute pyelonephritis and has been receiving intravenous fluids and ampicillin plus aminoglycoside for the past 5 days, but the patient’s temperature remains elevated, and the patient is still in pain and complains of nausea. The patient should be evaluated for: