Pediatric Examination and Board Review (74 page)

(A) α
₁
-antitrypsin deficiency

(B) biliary atresia

(C) neonatal hepatitis

(D) choledochal cyst

(E) none of the above

8.
If this child had a systolic ejection murmur with a fixed split second heart sound, what additional test(s) would you order?

(A) chest radiograph

(B) echocardiogram

(C) ophthalmology examination

(D) A, B, C

(E) A, B

9.
If this child’s weight was 3.9 kg at presentation, what further evaluation is indicated?

(A) sweat test

(B) thyroid function

(C) serum glucose level

(D) calorie count

(E) all of the above

10.
If this child had been treated with amoxicillin suspension for the past week for otitis media, what additional evaluation is indicated?

(A) serum glucose, lactic acid, uric acid, magnesium, and phosphate levels

(B) serum fructoaldolase level

(C) PT, NH
₃
level

(D) A and C

(E) ultrasound, α
₁
-antitrypsin level, urine reducing substance, urine culture

11.
The patient from question 2 had an additional workup, with the following results:

Urine culture: no growth in 48 hours

Urine reducing substances: negative

α
₁
-antitrypsin level: 198

Ultrasound: normal liver echogenicity, no biliary dilation and no masses

This patient’s diagnosis is likely to be

(A) neonatal hepatitis

(B) biliary atresia

(C) congenitally acquired hepatitis B

(D) TORCH infection

(E) undetermined; there is not enough information to make a diagnosis

12.
Which test is best used to distinguish biliary atresia from neonatal hepatitis?

(A) hepatobiliary scintigraphy

(B) liver biopsy

(C) endoscopic retrograde cholangiopancreatography (ERCP)

(D) abdominal computed tomography (CT)

(E) gallbladder ultrasound

13.
It is vital to a patient’s long-term prognosis for the diagnosis of biliary atresia to be made before

(A) 1 month of age

(B) 2 months of age

(C) 6 months of age

(D) 12 months of age

(E) the age the diagnosis is made is not important

14.
If this patient is diagnosed with biliary atresia, the next step is

(A) repeat liver biopsy in 3 months

(B) biliary stent

(C) cholecystostomy

(D) Kasai procedure

(E) liver transplantation

15.
If this patient is diagnosed with neonatal hepatitis, the next step is

(A) start fat-soluble vitamins

(B) start ganciclovir

(C) start ursodiol

(D) A and C

(E) B and C

16.
Standard medical treatment for cholestasis includes

(A) ursodiol treatment

(B) vitamin A, D, E, and K supplementation, nutritional support, ursodiol treatment, and treatment for pruritus

(C) vitamin K supplementation and nutritional support

(D) A and C

(E) none of the above

17.
If a patient with cholestatic liver disease was 4 days old instead of 4 weeks old, the likely diagnosis would be

(A) biliary atresia

(B) viral infection

(C) bacterial infection

(D) ornithine transcarbamylase deficiency

(E) B and C

18.
Suppose the patient in question 17 had a platelet count of 23,000, a PT of 20 seconds (INR 4), low fibrinogen, and an elevated d-dimer concentration. Furthermore, the patient has a palpable spleen and no palpable liver. Further evaluation would include

(A) bacterial cultures, viral cultures, abdominal magnetic resonance imaging (MRI)

(B) bacterial cultures, viral cultures, liver biopsy

(C) bacterial cultures, viral cultures, bone marrow biopsy

(D) viral cultures, abdominal MRI, liver biopsy

(E) blood and urine cultures

ANSWERS

1.
(A)
The most important thing to determine is whether this child has conjugated or unconjugated hyperbilirubinemia. All other diagnostic and therapeutic steps are based on this distinction.

2.
(D)
Although the term
LFTs
(liver function tests) is commonly used, its meaning is often unclear. There are 3 distinct groups of “liver labs.” Serum transaminase (ALT and AST) elevation indicates hepatocellular damage or death (many causes). GGT and alkaline phosphatase are enzymes found in high concentration in the biliary system, and elevations indicate biliary tree disease. Bilirubin, PT, albumin, and NH
₃
are true LFTs and indicators of liver function. These laboratory values indicate cholestatic liver disease secondary to biliary disease with normal liver function.

Congenital hepatitis B causes a carrier state in most infants, and they have normal “liver labs.” In a small percentage of infants, it can cause fulminant hepatic failure. Neither of those scenarios is consistent with the laboratory values.

Each of the other entities can present with elevated GGT and alkaline phosphatase and no elevation in ALT and AST.

3.
(A)
The differential diagnosis of cholestatic liver disease in an otherwise healthy 1-month-old includes

Cholestatic disorders

Biliary atresia

Idiopathic neonatal hepatitis

Choledochal cyst

Alagille syndrome

Persistent familial intrahepatic cholestasis (PFIC)

Metabolic disorders

α
₁
-antitrypsin deficiency

Galactosemia

Disorders of bile acid synthesis

Other

Urinary tract infection

4.
(C)
Because there is an increased risk of cholangiocarcinoma in cyst remnants, choledochal cysts require complete surgical removal (see
Figure 46-1
).

FIGURE 46-1.
Classification of choledochal cysts. Type I, fusiform or cystic dilations of the extrahepatic biliary tree, is the most common type, making up >50% of the choledochal cysts. Type II, saccular diverticulum of an extrahepatic bile duct. Rare, <5% of choledochal cysts. Type III, bile duct dilatation within the duodenal wall (choledochoceles), makes up about 5% of choledochal cysts. Type IVa and IVb, multiple cysts, make up 5-10% of choledochal cysts. Type IVa affects both extrahepatic, and intrahepatic bile ducts while Type IVb cysts affect the extrahepatic bile ducts only. Type V, intrahepatic biliary cysts, is very rare and makes up 1% of choledochal cysts. (Reproduced, with permission, from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill; 2010: Fig. 32-22.)

5.
(C)
Vomiting and cataracts in a cholestatic 1-month-old is galactosemia until proven otherwise. The treatment is elimination of exposure to galactose (in the lactose of breast milk and cow’s milk formula).

6.
(B)
In patients with galactosemia, continued exposure to galactose causes inhibition of leukocyte bactericidal activity. This puts them at increased risk for
E coli
sepsis.

7.
(A)
The diagnosis of α
₁
-antitrypsin deficiency is possible because this is inherited in an autosomal codominant fashion. There are 3 predominant alleles: M, S, and Z. The M allele produces normal levels of α
₁
-antitrypsin. The S allele gives moderately low levels, and Z is associated with very low levels. The patient with ZZ is likely to have α
₁
-antitrypsin deficiency liver disease. Patients with SZ are at an increased risk for developing lung disease. Patients with at least 1 M allele are unlikely to have clinical disease.

8.
(D)
The murmur described is consistent with pulmonic stenosis. In infants with pulmonic stenosis and cholestatic liver disease, your index of suspicion for Alagille syndrome must be high. Other features include characteristic facies (this can be difficult to distinguish in an infant), pulmonic stenosis (echocardiogram), butterfly vertebrae (chest x-ray), and posterior embryotoxon (ophthalmologic examination).

9.
(E)
Clearly, this child has failure to thrive (FTT) and cholestasis. The differential diagnosis includes cystic fibrosis and hypopituitarism. Even in the face of pathology (conjugated hyperbilirubinemia) one must consider malnutrition contributing to the FTT. All of the tests listed would be indicated (see
Figure 46-2
).

FIGURE 46-2.
Failure to thrive. This infant has not been able to maintain a normal growth pattern and appears cachectic. (Reproduced, with permission, from Knoop KJ, Stack LB, Storrow AS, et al. Atlas of Emergency Medicine, 3rd ed. New York: McGraw-Hill; 2010:446. Photo contributor: Kevin J. Knoop, MD, MS.)