Which stage of NEC is characterized by pneumoperitoneum?

In the context of necrotizing enterocolitis (NEC), the presence of pneumoperitoneum indicates a perforation of the intestine, which is a severe complication commonly associated with advanced stages of the disease. Pneumoperitoneum refers to the presence of air in the peritoneal cavity, usually due to a ruptured bowel.

Stage 3 of NEC represents the most severe manifestations of the condition. Particularly, Stage 3b is characterized by the presence of both clinical and radiological signs of perforation, including pneumoperitoneum, alongside systemic deterioration of the patient. This stage represents a critical condition requiring immediate surgical intervention, as it indicates a significant risk of sepsis and other life-threatening complications due to bowel perforation.

In contrast, the earlier stages (Stage 1 and Stage 2) of NEC do not typically involve perforation and are more focused on inflammatory changes and gas in the bowel without the presence of free air in the abdominal cavity. Thus, the presence of pneumoperitoneum is a decisive factor that classifies the condition as Stage 3b.