RNC-NIC Congenital Anomalies 3

Question 1

A neonate with Trisomy 21 (Down syndrome) is found to have bilious vomiting on day 1 of life. Which diagnosis must be excluded first?

Accepted Answer

Duodenal atresia

Answer

Duodenal atresia occurs in approximately 30% of neonates with Down syndrome and presents with bilious vomiting and a 'double-bubble' sign on X-ray.

Question 2

Which finding on abdominal X-ray is pathognomonic for duodenal atresia?

Accepted Answer

Double-bubble sign with absent distal bowel gas

Answer

The double-bubble sign represents air in the stomach and proximal duodenum with no distal gas, confirming complete duodenal obstruction.

Question 3

A neonate with Hirschsprung disease undergoes a rectal biopsy. Which histologic finding confirms the diagnosis?

Accepted Answer

Absence of ganglion cells in the myenteric and submucosal plexuses

Answer

Hirschsprung disease is defined by the absence of ganglion cells (aganglionosis) in the myenteric and submucosal plexuses of the affected bowel segment.

Question 4

A 3-day-old neonate presents with failure to pass meconium, abdominal distension, and bilious vomiting. Rectal examination produces an explosive release of stool and gas. This finding MOST suggests:

Accepted Answer

Hirschsprung disease

Answer

Explosive release of stool after rectal examination is a classic clinical sign of Hirschsprung disease, indicating the aganglionic segment relaxes with stimulus.

Question 5

Which condition is MOST commonly associated with meconium ileus at birth?

Accepted Answer

Cystic fibrosis

Answer

Approximately 90% of neonates with meconium ileus have cystic fibrosis, caused by thick, inspissated meconium blocking the terminal ileum.

(RNC-NIC) Registered Nurse Certified in Neonatal Intensive Care Practice Test

(RNC-NIC) Registered Nurse Certified in Neonatal Intensive Care Practice Test

RNC-NIC Congenital Anomalies 3