Clinical Chemistry and the Pediatric Patient

Question 1

All of the following represent normal physiology of the newborn except
a. Weight of 2.4 kg
b. Immature liver function and inability to eliminate excess bilirubin
c. Closure of the ductus arteriosus and a shift of blood flow through the
heart
d. 4 to 6 months for the infant’s body weight to double

Answer 1

a. Weight of 2.4 kg

Question 2

Which of the following choices is false concerning blood obtained by heel
stick (capillary) and venipuncture (venous)?
a. The chemical composition of the sera derived from each is identical.
b. The capillary specimen is likely contaminated with interstitial fluid and
tissue debris.
c. Venous blood contains higher bilirubin and calcium concentrations.
d. Capillary blood contains less concentrated proteins due to mixing with
interstitial fluid.

Answer 2

a. The chemical composition of the sera derived from each is identical.

Question 3

Under normal conditions, what is the maximum amount of blood that should
be drawn from a 30-kg child during a single blood draw?
a. 60 mL
b. 80 mL
c. 40 mL
d. 20 mL

Answer 3

a. 60 mL

Question 4

When choosing a chemistry analyzer for a pediatric laboratory, it is necessary
to
a. Incorporate total laboratory automation
b. Be able to analyze from small volumes
c. Have a rapid turnaround time
d. Ensure a minimum specimen dead volume

Answer 4

b. Be able to analyze from small volumes

Question 5

Which of the following is true regarding POCT?
a. Results are generally available more rapidly than with traditional
laboratory tests.
b. POCT is usually less expensive than traditional laboratory
measurements.
c. The device cannot be linked to the hospital information system.
d. Quality control samples are not needed.

Answer 5

a. Results are generally available more rapidly than with traditional
laboratory tests.

Question 6

Which of the following conditions are related to acidosis in the newborn?
a. Anoxia and trauma during delivery
b. Respiratory distress syndrome
c. Hyperammonemia caused by liver disease
d. Hyperventilation

Answer 6

a. Anoxia and trauma during delivery

Question 7

Which of the following are characteristics of renal development and function
during the neonatal period?
a. Control the rate of salt and water loss and retention
b. GFR about 50% of the rate seen in older children
c. Completely developed by 24 weeks of gestation
d. Have a maximum solute concentrating power of approximately 30% of
an adult kidney

Answer 7

a. Control the rate of salt and water loss and retention

Question 8

Which of the following statements about the neonatal thyroid system is true?
a. Secondary hypothyroidism is usually diagnosed by measuring a low
TSH level.
b. Thyroid hormones (T4 and T3) are less than 50% bound to thyroidbinding globulins.
c. CH is a very rare and untreatable disorder.
d. A low measured TSH level may be due to a global pituitary gland
dysfunction (panhypopituitarism).

Answer 8

a. Secondary hypothyroidism is usually diagnosed by measuring a low
TSH level.

Question 9

. Cystic fibrosis
a. Is diagnosed by the measurement of elevated chloride concentration in
sweat following iontophoresis
b. Is a very uncommon genetic disease
c. Is caused by only a single type of mutation in the CF transmembrane
regulator (CFTR) gene
d. Is characterized by thin, watery mucous secretions in the lungs and
pancreatic ducts

Answer 9

a. Is diagnosed by the measurement of elevated chloride concentration in
sweat following iontophoresis