Necrotizing enterocolitis: Year of the Zebra 2024

Necrotizing enterocolitis, or NEC for short, is a rare life-threatening condition that involves inflammation and necrosis, or tissue death, of the intestines.

This can lead to perforation of the intestinal wall and severe infection. NEC usually occurs within the first 2 weeks of life and mostly affects premature babies, especially those with very low birth weights, though it can occur in full-term infants too.

This is because their immune system and gut barrier are not fully mature, making it easier for harmful bacteria to invade the intestinal wall.

Among premature babies, those fed with formula rather than breast milk seem to be at higher risk. This is likely due to the protective effect of breast milk in the intestines, as it contains a more natural balance of sugars that promote the growth of beneficial bacteria in the baby’s gut, as well as antibodies and other anti-inflammatory compounds that prevent harmful microbes from adhering to the intestinal lining.

Early symptoms of NEC include feeding intolerance, where the baby has difficulty digesting formula or breast milk, and abdominal bloating or swelling.

Infants may also present vomiting, sometimes containing bile, along with diarrhea and bloody stools. As the condition progresses, the baby's abdomen may become tender, red, or shiny.

In cases of intestinal perforation, crepitus—or a crackling sound—may be heard when lightly pushing on the abdomen due to free air in the abdomen.

Infants may also show signs of infection, such as fever, breathing problems, low blood pressure, and poor circulation. Despite advancements in care, NEC continues to have a high mortality rate, especially in extremely premature infants, meaning those born before 28 weeks’ gestation.

Infants who survive usually face many long-term complications including short bowel syndrome, intestinal strictures, and neurodevelopmental delays.

NEC is usually diagnosed clinically, based on history and physical exam findings. Diagnosis is supported by laboratory tests to look for signs of infection and X-ray imaging of the abdomen.

Common findings on X-ray include dilated loops of intestine and gas within the intestinal wall. If intestinal perforation has occurred, it's also possible to see free air within the abdominal cavity that has escaped from the intestines.

Although X-rays can support the diagnosis, they are not required to confirm it since characteristic X-ray findings are not always visible.

Treatment of NEC should be started as soon as the diagnosis is suspected. It's important to promote intestine rest by stopping oral feeding and emptying the stomach using an orogastric or nasogastric tube.

Intravenous fluids are administered to provide hydration and nutrients during the period of no feeding, and antibiotics are given to treat the infection.

In mild cases, there may be a good response to these treatments and no further interventions are needed. In severe cases though, infants may deteriorate quickly and require evaluation by a surgical team.

The surgical team may perform an exploratory laparotomy to assess the entire intestine for tissue death or perforation and remove the dead tissue if needed.

In such cases, a stoma—or an opening in the abdomen—may be created to divert stool, allowing the remaining intestine to heal.

Following surgery, infants may require ongoing nutritional support and monitoring for potential complications. Alright, as a quick recap...

Necrotizing enterocolitis is a rare life-threatening condition primarily seen in premature infants, where portions of the intestines undergo necrosis, or tissue death.

Symptoms may include abdominal swelling, vomiting, diarrhea, feeding intolerance, and bloody stools. It's diagnosed through a combination of history, physical examination, imaging tests, and laboratory tests.

Treatment may involve antibiotics, gastric decompression, supportive management, and surgery to remove the damaged intestine.