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Renal Functional Development in

Children

Victoria F. Norwood; Craig A. Peters

Questions

1.A 2-month-old infant born at 32 weeks gestation is expected to have:

a.completed nephrogenesis but immature renal functional abilities.

b.incomplete nephrogenesis and immature renal functional abilities.

c.completed both nephrogenesis and renal functional maturation.

d.functionally mature nephrons but ongoing formation of additional nephrons.

e.no increased risk of chronic kidney disease (CKD) compared to an infant born at 38 weeks gestation.

2.A 2-week-old boy with bilateral moderate hydronephrosis who was born at 30 weeks gestation is found to have a serum creatinine of 0.7 mg/dL. This would suggest:

a.significant renal dysfunction, possibly due to posterior urethral valves.

b.maternal renal function.

c.moderate renal dysfunction unrelated to his hydronephrosis.

d.normal renal function without evidence of obstruction.

e.likely hemolyzed specimen with inaccurate creatinine level.

3.A 4-year-old boy presents with swelling and decreased urine output. He has had eyelid edema on awakening for the past week. His blood pressure is 90/50 mm Hg, and he has marked eyelid edema, distended abdomen, and pitting edema of the legs and feet. Urinalysis showed a specific gravity of 1.030, pH 5, 3 + protein, and trace of blood. Serum studies show a sodium level of 131 mEq/L, blood urea nitrogen value of 30 mg/dL, creatinine level of 0.3 mg/dL, and albumin level of 1.6 g/dL. The appropriate next step in management is:

a.quantitation of urinary protein excretion, renal ultrasound, and lipid panel.

b.initiation of oral prednisone.

c.workup for occult malignancy.

d.quantitation of urinary protein excretion, renal ultrasound, lipid panel, and initiation of prednisone therapy.

e.quantitative protein excretion, lipid panel, and prednisone therapy.

4.A 6-year-old, healthy girl undergoes a routine physical examination. Urinalysis reveals a specific gravity of 1.020, pH 6, trace protein, and moderate amount of blood on dipstick testing. The microscopic test shows 5 to 6 red blood cells per high-powered field. An inappropriate next step is:

a.renal ultrasonography.

b.random urine calcium and creatinine determinations.

c.clean-catch urine culture.

d.an empirical 10-day course of antibiotics.

e.a repeat urinalysis in 2 weeks.

5.A urinalysis in an 8-year-old boy shows a specific gravity of 1.030, pH 5, trace protein, and moderate amount of blood. He has a normal physical examination, including blood pressure of 96/56 mm Hg. On further history he was hospitalized 2 months ago with poststreptococcal glomerulonephritis. The most appropriate course of action is:

a.cystoscopy.

b.renal ultrasonography.

c.a course of antibiotics after obtaining a urine culture.

d.to reassure his family and obtain records from the outside institution.

e.computed tomography (CT).

6.A 6-year-old boy is seen in the emergency department with the new onset of left-sided flank pain, gross hematuria, and vomiting. His blood pressure is 120/70 mm Hg, and the physical examination reveals right costovertebral angle tenderness. The urinalysis shows brown urine with a specific gravity of 1.030, pH 7, large amount of blood, and 2 + protein. The next step in diagnostic evaluation should NOT include:

a.high-resolution CT of abdomen/pelvis without contrast.

b.microscopic examination of the urine.

c.cystoscopy.

d.renal ultrasonography.

e.serum electrolyte determination.

7.An 8-year-old is seen in the emergency room with 24 hours of severe left flank pain and nausea. Urinalysis shows a specific gravity of 1.024, pH of 6.3, and a serum creatinine of 0.4 mg/dl. He is afebrile and has had no surgery. The most appropriate next step is:

a.no further imaging is needed.

b.double-J ureteral stent placement.

c.hospital admission and 4 days of antibiotics.

d.abdominal ultrasound.

e.CT urogram with and without contrast.

8.A 9-year-old girl presents after passing a 3-mm stone. On analysis, the stone is composed 100% of calcium oxalate. The next step is to:

a.start a thiazide diuretic.

b.obtain a 24-hour urine collection to test for calcium, creatinine, oxalate, and citrate.

c.start potassium citrate.

d.restrict dietary calcium.

e.restrict dietary oxalate.

9.A 6-year-old boy is seen in the emergency department with new onset of headache and gross hematuria. He has no dysuria or fever but has vomited three times. He had a sore throat the week before, but it has resolved. His blood pressure is 140/90 mm Hg, and physical examination reveals a heart murmur. The urinalysis shows brown urine with a specific gravity of 1.030, pH 7, large amount of blood, and 2 + protein. The next step in the diagnostic evaluation should include all of the following EXCEPT:

a.CT of the abdomen and pelvis.

b.comprehensive metabolic panel.

c.C3 determination.

d.antistreptolysin O titer.

e.microscopic examination of the urine.

.A 3-year-old boy is seen in the emergency department with a respiratory problem and gross hematuria. He has no dysuria or abdominal pain but has fever, rhinorrhea, and cough. His blood pressure is 120/70 mm Hg, and physical examination shows rhinorrhea, mild pharyngeal erythema, and no peripheral edema or abdominal tenderness. The urinalysis shows brown urine with a specific gravity of 1.030, pH 7, large amount of blood, and 2 + protein. (His mother also has had hematuria in the past, and his maternal uncle is deaf and on hemodialysis.) The next step in diagnostic evaluation includes all of

the following EXCEPT:

a.renal biopsy.

b.antistreptolysin O titer and C3.

c.comprehensive metabolic panel.

d.microscopic examination of the urine.

e.CT of the abdomen and pelvis.

.A 16-year-old boy with end-stage renal disease is managed with peritoneal dialysis (PD). He develops abdominal pain, vomiting, and a fever of 100.9° F. The next step in management is to:

a.obtain blood and urine cultures.

b.start broad-spectrum antibiotics.

c.collect a specimen of dialysate for white blood cell count and culture.

d.change to hemodialysis.

e.administer intraperitoneal antibiotics.

.During an evaluation for ongoing malaise and poor appetite, which followed initiation of treatment for otitis media four earlier, an 8-year-old boy is found to have a blood urea nitrogen level of 40 mg/dL and a creatinine of 1.4 mg/dL. His urinary sodium level is 13 mEq/L, fractional excretion of sodium (FENa) is

0.8%, and urinary osmolality is 410 mOsm/Kg. The most likely cause of his renal insufficiency is:

a.posterior urethral valves.

b.dehydration

c.interstitial nephritis.

d.hemolytic uremic syndrome.

e.previously unknown bilateral ureteropelvic junction obstruction.

.A 9-year-old boy is found during routine examination to have a blood pressure of 120/90 mm Hg. The child was calm, and a properly sized blood pressure cuff was used for the measurement. The best next step in management is to:

a.repeat the measurement next week in the office.

b.obtain a fasting lipid profile.

c.perform renal ultrasonography.

d.obtain peripheral vein renin levels.

e.perform ambulatory blood pressure monitoring (ABPM).

.An otherwise healthy 14-year-old boy is found to have 2 + protein on a urinalysis obtained as part of a sports physical for football. The most appropriate initial step in the evaluation should be:

a. referral to the first available pediatric urologist or nephrologist.