Differential Diagnosis for a 10-hour-old Boy with Bilious Emesis
The clinical presentation of this neonate, including bilious emesis, failure to pass meconium, physical examination findings suggestive of a genetic syndrome, and the abdominal radiograph showing massive gastric distension with an absence of distal bowel gas, guides the differential diagnosis.
Single Most Likely Diagnosis
- Duodenal Atresia: This condition is strongly suggested by the presence of bilious emesis, failure to pass meconium, and the abdominal radiograph showing a "double bubble" sign (massive gastric distension with no gas in the small bowel), which is characteristic of duodenal atresia. The physical examination findings are also consistent with Down syndrome, which is associated with an increased risk of duodenal atresia.
Other Likely Diagnoses
- Jejunoileal Atresia: Similar to duodenal atresia, jejunoileal atresia can cause bilious vomiting and intestinal obstruction. However, the pattern of gas distribution on the abdominal radiograph might differ, typically showing multiple air-filled loops of bowel.
- Hirschsprung's Disease: Although it primarily presents with constipation, in severe cases, it can cause intestinal obstruction leading to bilious vomiting. The absence of meconium passage supports this diagnosis.
- Congenital Heart Disease: The presence of a loud holosystolic murmur suggests congenital heart disease, which can be associated with genetic syndromes and may contribute to the clinical presentation, although it's not directly causing the gastrointestinal symptoms.
Do Not Miss Diagnoses
- Volvolus: A life-threatening condition that requires immediate surgical intervention. Although less likely given the radiographic findings, it's crucial to consider due to its high mortality if missed.
- Intestinal Malrotation with Midgut Volvulus: This condition can present with bilious vomiting and requires urgent diagnosis and treatment to prevent intestinal ischemia and necrosis.
- Necrotizing Enterocolitis: Although more common in premature infants, it can occur in term infants and is a medical emergency.
Rare Diagnoses
- Congenital Diaphragmatic Hernia: Can cause intestinal obstruction and respiratory distress due to herniation of abdominal contents into the thoracic cavity.
- Abdominal Wall Defects (Gastroschisis or Omphalocele): These conditions involve defects in the abdominal wall through which intestinal contents can herniate, potentially causing obstruction and other complications.
- Meconium Ileus: Associated with cystic fibrosis, it presents with intestinal obstruction due to inspissated meconium in the terminal ileum.