the presence of prerenal azotemia is a probable indicator for hospitalization for cap. which of the following is an initial laboratory result that would alert a nurse to this condition? serum creatinine of 1.2 mg/dl. glomerular filtration rate (gfr) of 100 ml/min. blood urea nitrogen (bun)-to-creatinine ratio (bun:cr) >20. bun of 18 mg/dl.