Most common gastrointestinal medical and/or surgical emergency occurring in neonates

Etiology o Remains unknowno Ischemia and/or reperfusion injury may play a roleo Cluster cases and outbreaks in nurseries imply an infectious etiology

A single causative organism has not been foundo Translocation of intestinal flora across compromised mucosa may play a role

Incidence and age at onset o More common in premature infants

But can also be seen in term babieso Inversely related to birth weight and gestational ageo Term infants develop NEC earlier after birth than preemies

Average age of onset occurs within first week of life Affected term neonates are usually systemically ill with other

conditions such as birth asphyxia, respiratory distress or congenital heart disease

o Premature babies are at risk for several weeks after birtho Babies who are breastfed have a lower incidence of NEC than formula-fed

babies Clinical findings

o Initial symptoms may be subtle and can include the following Feeding intolerance Delayed gastric emptying Abdominal distention and/or tenderness Ileus/decreased bowel sounds

Imaging findings o Acute disease most commonly affects the terminal ileumo Plain film of the abdomen remains method in which disease is diagnosed most

ofteno Findings include

Dilated loops of bowel Thickened bowel walls

Fixed and dilated loop that persists is especially worrisome Absence of bowel gas Pneumatosis intestinalis

Pathognomonic of NEC in newborn o Linear radiolucency parallels bowel lumen within bowel

wallo Represents air that has entered from the lumen

Red arrows point to linear bands of radiolucency which parallel the wall of thebowel indicating the presence of pneumatosis intestinalis in necrotizing enterocolitisFor a the same photo without the arrows, click here

Abdominal free air Ominous         

o Usually requires emergency surgical intervention May require a left lateral decubitus view to be seen

Portal venous gas Originally thought to be ominous but is now considered less so Appears as linear branching areas of decreased density over periphery of the

liver o Represents air in portal venous system

Ascites Late finding Develops after perforation when peritonitis is present

Complications o Occur in about 75% of all patients survive

Of those who survive, 50% develop a long-term complicationo Two most common complications are intestinal stricture and short-gut

syndromeo Intestinal strictures

Can develop in infants with or without a preceding perforation

Incidence is 25-33% Strictures most commonly involve the left side of the colon Diagnosed with barium enema

o Short-gut syndrome Malabsorption syndrome resulting from removal of excessive or

critical portions of small Neonatal gut will grow this growth may take as long as 2 years to

occur Mortality

o Mortality rate ranges from 10-44% in infants weighing less than 1500 g