11-23-2007, 08:58 AM
A 5-month-old male infant has a urine output of less than 0.1 mL/kg/hr shortly after undergoing
major surgery. On examination, he has generalized edema. His blood pressure is 94/48 mm
Hg, pulse is 140/min, and respirations are 20/min. His blood urea nitrogen is 38 mg/dL, and
serum creatinine is 1.4 mg/dL. Initial urinalysis shows a specific gravity of 1.018 and 2+
protein. Microscopic examination of the urine sample reveals 1 WBC per high-power field
(HPF), 18 RBCs per HPF, and 5 granular casts per HPF. His fractional excretion of sodium is
3.2 %. Which of the following is the most appropriate next step in diagnosis?
A. CT of the abdomen and pelvis
B. Cystourethrography
C. Intravenous pyelography
D. Renal biopsy
E. Renal ultrasonography
major surgery. On examination, he has generalized edema. His blood pressure is 94/48 mm
Hg, pulse is 140/min, and respirations are 20/min. His blood urea nitrogen is 38 mg/dL, and
serum creatinine is 1.4 mg/dL. Initial urinalysis shows a specific gravity of 1.018 and 2+
protein. Microscopic examination of the urine sample reveals 1 WBC per high-power field
(HPF), 18 RBCs per HPF, and 5 granular casts per HPF. His fractional excretion of sodium is
3.2 %. Which of the following is the most appropriate next step in diagnosis?
A. CT of the abdomen and pelvis
B. Cystourethrography
C. Intravenous pyelography
D. Renal biopsy
E. Renal ultrasonography