Review Question - QID 212806

This patient is displaying signs of necrotizing enterocolitis (e.g., fever, acute change in feeding, diarrhea, and abdominal distention), which commonly occurs in premature infants (< 31 weeks) who are formula fed. Findings include gas within the walls of the small or large intestine on radiograph, or pneumatosis intestinalis.

Necrotizing enterocolitis is one of the most common gastrointestinal emergencies in newborns and is especially common in premature, formula-fed infants with low birth weights. It is characterized by ischemic necrosis of the intestinal mucosa, which subsequently leads to severe inflammation, invasion of enteric gas-forming organisms, and dissection of gas into the bowel wall and portal venous system. Most patients are generally healthy, feeding well, and growing prior to developing the condition. The most common presentation is a sudden change in feeding tolerance; other signs include abdominal distention, tenderness, vomiting, diarrhea, hematochezia, respiratory distress, temperature instability, and rarely, septic shock. Diagnosis is often made clinically along with radiographic findings. Management includes both medical (e.g., hydration, bowel rest, antibiotics, and gastric decompression) and surgical options.

Illustration A is an abdominal radiograph demonstrating the presence of gas within the bowel walls (arrow).

Incorrect Answers:
Answer 1: Absence of ganglion cells on rectal biopsy is seen in Hirschsprung disease, which often presents with failure to pass meconium, abdominal distention, and bilious vomiting. This patient had “a normal stool pattern previously.”

Answer 2: Double bubble sign on abdominal radiograph can be seen in cases of duodenal atresia or annular pancreas. Patients often present with bilious vomiting and abdominal distention. This patient’s presentation is more suggestive of necrotizing enterocolitis.

Answer 3: High levels of cow’s milk IgE can be found in patients with milk protein allergy, which presents with abdominal distention and increased stooling that can be bloody. However, this is extremely rare in preterm infants and rarely occurs before six weeks of age.

Answer 5: Positive blood cultures for group B streptococcus (GBS) will be seen in sepsis secondary to GBS. Patients will have unstable vital signs (as seen in this patient); however, this patient’s gastrointestinal symptoms are more in line with that of necrotizing enterocolitis.

Bullet Summary:
Pneumatosis intestinalis, or the presence of gas within the bowel wall, is a characteristic radiographic finding of necrotizing enterocolitis.