Review Test

1.A 3-week-old uncircumcised male infant presents with a 2-day history of very poor feeding. He now takes only 1 oz of formula every 3 hours, instead of the usual 2–3 oz. The parents state that their son has become increasingly irritable, and they deny fever, vomiting, or other symptoms. You perform a laboratory evaluation to look for evidence of infection. A urinalysis demonstrates 25–50 white blood cells per high-power field. You suspect that the infant has a urinary tract infection (UTI). Which of the following statements regarding UTI in this infant is correct?

A.There would be no significant difference in his risk of UTI had he been circumcised.

B.During infancy, the risk of developing a UTI is the same as that of an infant girl.

C.A clean “bagged” urine sample is adequate for culture in this febrile infant with no obvious source of infection.

D.If diagnosed with a UTI, this infant has an increased risk of having vesicoureteral reflux as compared with an infant without a UTI.

E.This infant should be treated empirically with oral antibiotics on an outpatient basis and reevaluated within 24 hours.

2.A 5-year-old boy is brought to your office by his parents, who noticed that when their son urinated earlier in the day, his urine appeared red. Dysuria, urinary frequency, and fever are absent, and he is well appearing on examination. Which of the following statements regarding this patient’s presentation and subsequent workup is correct?

A.This patient may be diagnosed with microscopic hematuria if there are ≥10 red blood cells (RBCs) per high-power field on a single urine sample.

B.On urinalysis, RBCs that appear as biconcave disks indicate that they originated in the glomerulus, and this suggests that he has glomerulonephritis.

C.Because of his presentation with hematuria at a young age, this patient will likely have persistent microscopic hematuria.

D.This patient’s red-colored urine may have resulted from eating beets the previous day.

E.This patient’s urinary dipstick for blood may be falsely positive if he has recently ingested ascorbic acid (vitamin C).

3.A 4-year-old girl who recently returned from Southeast Asia presents with a history of watery diarrhea, vomiting, and decreased urine output. She is irritable and is crying, although she stops crying when held by her parents. Examination reveals tachycardia with a normal blood pressure, dry mucous membranes, and good peripheral perfusion with normal skin turgor. Which of the following statements regarding rehydration of this child is correct?

A.The goal of the emergency phase of intravenous rehydration is to restore or maintain intravascular volume to ensure perfusion of the vital organs. The type of intravenous fluids administered depends on the serum level of sodium in the blood.

B.Appropriate bolus fluids in the emergency phase of intravenous rehydration should include 20 mL/kg of one half–normal saline solution.

C.If this patient is isonatremic or hypernatremic, her fluid deficits should be replaced over 24 hours, but if she is hyponatremic, her fluid deficits should be replaced over 48 hours.

D.If stool losses continue, these losses should not be replaced until all the deficit fluids are replaced.

E.Oral rehydration therapy may be effective even if this child has a secretory diarrhea.

4.A 5-year-old boy has a 3-day history of headache, “puffiness,” and dark-colored urine. Physical examination reveals hypertension and periorbital and peripheral edema. Urinalysis reveals hematuria with red blood cell casts and 2+ proteinuria. The diagnosis of poststreptococcal glomerulonephritis is suspected pending further evaluation. Which of the

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following statements regarding this patient’s diagnosis is correct?

A.If diagnosed with poststreptococcal glomerulonephritis, this patient would be expected to have mild to moderate impairment of renal function and normal serum complement levels.

B.This patient is likely to have had an infection of the skin or pharynx with a nephritogenic strain of group A β-hemolytic streptococcus 60–90 days before the current presentation.

C.A negative antistreptolysin O titer would rule out the diagnosis of poststreptococcal glomerulonephritis in this patient.

D.Antibiotic treatment with penicillin for streptococcal pharyngitis would have prevented this patient’s glomerulonephritis.

E.If the diagnosis of poststreptococcal glomerulonephritis is confirmed, the prognosis for this patient is excellent; complete recovery usually occurs.

5.A previously healthy 3-year-old girl presents with a 2-week history of progressive facial edema. You suspect nephrotic syndrome. Which of the following statements regarding this patient’s presentation, evaluation, and management is correct?

A.This patient’s nephrotic syndrome is most likely a consequence of a primary glomerular disease, such as IgA nephropathy.

B.This patient’s age of presentation is atypical; the peak age of presentation of nephrotic syndrome is between the ages 5 and 15 years.

C.This patient should undergo renal biopsy to confirm the diagnosis and to establish an appropriate approach to management.

D.If this patient develops a high fever, she should be empirically treated with antibiotics to cover possible pneumococcal peritonitis.

E.Discovery of heavy proteinuria, hypoalbuminemia, and hypocholesterolemia on laboratory testing would confirm the diagnosis.

6.A previously healthy 3-year-old boy presents with lethargy, pallor, and bloody diarrhea. He has had bloody stools for 4 days, and in the past 2 days he has developed fatigue and pale skin. He is drinking less than normal, and his urine output is somewhat decreased. The parents deny any travel or medication use. Physical examination reveals mild hypertension, pale mucous membranes, abdominal tenderness, and a petechial skin rash on the trunk and extremities. Hemolytic uremic syndrome (HUS) is suspected. Which of the following statements regarding the suspected diagnosis is correct?

A.Given the nature of this patient’s symptoms and his young age, he is most likely to have atypical HUS.

B.Parenteral antibiotic treatment with gentamicin is indicated for the treatment of suspected Escherichia coli hemorrhagic colitis.

C.Although he has a petechial rash, his platelet count will be normal.

D.The prognosis is poor; he will likely have a chronic relapsing course, with a high chance of end-stage renal disease.

E.The renal impairment is caused by toxin binding to renal vascular endothelial cells.

7.A 14-year-old Japanese American boy has 3+ protein and 4+ blood with red blood cell casts on a routine screening urinalysis conducted as part of a health maintenance evaluation. Further questioning reveals two prior episodes of “brown-colored urine” concurrent with upper respiratory tract infections during the last 3 years. Which of the following is the most likely diagnosis?

A.Membranous nephropathy

B.Systemic lupus erythematosus nephritis

C.IgA nephropathy

D.Membranoproliferative glomerulonephritis

E.Henoch–Schönlein purpura nephritis

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8.A 3-year-old girl has a 2-day history of fever, irritability, and emesis. Urine culture grows >100,000 colonies/mL of Escherichia coli. She is treated with cephalexin and returns 10 days later for an imaging evaluation to rule out a structural abnormality of the urinary tract. A voiding cystourethrogram reveals grade 2 vesicoureteral reflex (VUR), but her renal ultrasound is normal. Which of the following statements regarding VUR is correct?

A.Inheritance of VUR is most likely to be autosomal recessive.

B.The chance of developing chronic renal insufficiency as a result of VUR is 50%.

C.Referral to a pediatric urologist for ureteral reimplantation is appropriate.

D.The VUR is likely caused by a short submucosal tunnel in which the ureter inserts through the bladder wall.

E.Because this patient has grade 2 VUR, she should be placed on prophylactic antibiotics.

9.A 1-year-old boy has a 2-day history of irritability, decreased oral intake, decreased urine output, occasional watery diarrhea, and tactile fever. On physical examination, he is nontoxic and moderately dehydrated and has a temperature of 38.3°C (101°F). You admit him for intravenous rehydration because of his dehydration. Which of the following statements regarding his maintenance fluid and electrolyte requirements is correct?

A.His maintenance sodium requirement is approximately 1 mEq/kg/day.

B.His maintenance water requirement is 1000 mL/m2/day of body surface area.

C.His fever will result in increased insensible losses, and maintenance fluids should therefore be increased by 5% for every degree of temperature above 38°C.

D.His maintenance fluid calculations need to be adjusted for increased ongoing losses should he develop protracted vomiting or profuse watery diarrhea.

E.Maintenance fluid calculations for this child take into account both sensible and

insensible losses.

10.A 4-day-old male infant has gross hematuria. His parents noticed the bleeding today when

they changed his diaper. Perinatal history is remarkable for a term gestation complicated by gestational diabetes mellitus. Physical examination reveals hypertension and a right-sided

flank mass. In addition, the infant appears very sleepy, and his mucous membranes are dry. Which of the following is the most likely explanation for his hematuria?

A.Maternal systemic lupus erythematosus nephritis

B.Adenovirus infection

C.Sickle cell disease

D.Hypercalciuria

E.Renal vein thrombosis

11.A 6-month-old female infant with a 2-week history of vomiting is brought to your office by her parents. The vomiting occurs three to four times per day, and her parents report she has been very fussy. Review of her growth records reveals very poor growth consistent with failure to thrive. A complete blood count is normal, but an electrolyte panel shows metabolic acidosis. Which of the following laboratory findings would be most consistent with suspected renal tubular acidosis?

A.Hypokalemia

B.Hyperphosphatemia

C.Hyperchloremia

D.Elevated serum anion gap

E.Hypocalcemia

The response options for statements 12–14 are the same. You will be required to select one answer for each statement in the following set.

A.Autosomal dominant

B.Autosomal recessive

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C.Sporadic

D.X-linked

For each patient, select the likely mode of inheritance of the disease.

1.A 6-month-old girl with bilateral abdominal masses and severe hypertension, whose older sister died as a neonate after being diagnosed with oligohydramnios.

2.A 12-year-old boy who has three renal cysts on a renal ultrasound that was performed for the evaluation of microscopic hematuria. The patient’s paternal grandfather died of a stroke at 32 years of age, and the patient’s father has hypertension.

3.A 15-year-old boy who has mild hearing loss, mild hypertension, hematuria, and proteinuria.

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