Diagnostic Criteria for Necrotizing Enterocolitis (NEC)

Necrotizing enterocolitis is among the most common and devastating diseases in neonates. The excessive inflammatory process initiated in the highly immunoreactive intestine in necrotizing enterocolitis extends the effects of the disease systemically, affecting distant organs such as the brain and placing affected infants at substantially increased risk for neurodevelopmental delays.

Diagnostic Criteria for Necrotizing Enterocolitis (NEC)
Suspected necrotizing enterocolitis

• Abdominal distention without radiographic evidence of pneumatosis intestinalis, portal venous gas, or free intraperitoneal air
• Unexpected onset of feeding intolerance

Definitive medical necrotizing enterocolitis

• Abdominal distention with pneumatosis intestinalis, portal venous gas, or both
• Other radiographic signs such as fixed, dilated loops of intestine and ileus patterns are not pathognomonic but should be treated as such

Surgical necrotizing enterocolitis

• Free intraperitoneal air on abdominal radiograph after initial medical signs and symptoms
• Persistent ileus pattern, abdominal distention, and radiographs that show an absence of bowel gas, coupled with deteriorating clinical and laboratory values (e.g., decreasing neutrophil and platelet counts)

Modified Bell´s Staging Criteria for Necrotizing Enterocolitis (NEC)

Stage	Systemic signs	Abdominal signs	Radiographic signs	Treatment
IA Suspected	Temperature instability, apnea, bradycardia, lethargy	Gastric retention, abdominal distention, emesis, heme-positive stool	Normal or intestinal dilation, mild ileus	NPO, antibiotics x 3 days
IB Suspected	Same as above	Grossly bloody stool	Same as above	Same as IA
IIA Definite, mildly ill	Same as above	Same as above, plus absent bowel sounds with or without abdominal tenderness	Intestinal dilation, ileus, pneumatosis intestinalis	NPO, antibiotics x 7 to 10 days
IIB Definite, moderately ill	Same as above, plus mild metabolic acidosis and thrombocytopenia	Same as above, plus absent bowel sounds, definite tenderness, with or without abdominal cellulitis or right lower quadrant mass	Same as IIA, plus ascites	NPO, antibiotics x 14 days
IIIA Advanced, severely ill, intact bowel	Same as IIB, plus hypotension, bradycardia, severe apnea, combined respiratory and metabolic acidosis, DIC, and neutropenia	Same as above, plus signs of peritonitis, marked tenderness, and abdominal distention	Same as IIA, plus ascites	NPO, antibiotics x 14 days, fluid resuscitation, inotropic support, ventilator therapy, paracentesis
IIIB Advanced, severely ill, perforated bowel	Same as IIIA	Same as IIIA	Same as above, plus pneumoperitoneum	Same as IIA, plus surgery

DIC: disseminated intravascular coagulation

NPO: “nil per os” or nothing by mouth