Necrotizing enterocolitis is the death of intestinal tissue. It most often affects premature or sick babies.

1. Necrotizing enterocolitis
Alan Mathew Skaria
TSMU

2. Overview
Necrotizing enterocolitis is the necrosis(death) of intestinal tissue. It
primarily affects premature infants or sick newborns.
"Necrotizing" means the death of
tissue, "entero" refers to the small
intestine, "colo" to the large intestine,
and "itis" means inflammation.

3. Necrotizing Enterocolitis
• One of the most serious GI diseases of neonates,
especially preterm infants.
• NEC involves infection and inflammation that causes
destruction of the bowel (intestine) or part of the bowel
• Intestinal necrosis that can involve all layers of the bowel.
• Most commonly involves the ileum and colon but can
occur anywhere.

4. Epidemiology
• Most common GI emergency in newborns
• Incidence 3 per 1000 live births
• Incidence is 30 per 1000 live births for low birth weight
neonates
• 90% are premature
• Incidence is 7% in newborns <1500 g
• Race: blacks > non-Hispanic whites

5. Risk Factors
• Prematurity (<34 weeks)
• Low birth weight (<1500g)
– Occurs in 2-10% of neonates <1500g
• Enteral feeding of premature infants
– Hypertonic formula/enteral meds
– Breast milk protective compared to formula
– Rate of feeds and timing of initiation of feeds don’t
change rates of NEC
• Term infant with pre-existing illness

6. Causes:
• The exact cause of NEC is unknown
• These premature infants have immature bowels, weakened
by too little oxygen or blood flow. So when feedings are
started, the added stress of food moving through the intestine
allows bacteria normally found in the intestine to invade and
damage the wall of the intestinal tissues. The damage may
affect only a short segment of the intestine or can progress
quickly to involve a much larger portion.

7. Pathogenesis:
• A combination of risk factors predispose pts to NEC
• An insult begins the process
• Progression is due to stasis, bacterial overgrowth,
vascular factors
• May resolve, or may progress to perforation
intenstine with gas bubbles in the intestinal wall and portions of the intestine
that is frankly necrotic

8. CIRCULATORY INSTABILITY
PRIMARY INFECTIOUS AGENTS
Hypoxic-ischemic event
Bacteria, Bacterial toxin, Virus, Polycythemia
Fungus
MUCOSAL INJURY
INFLAMMATORY MEDIATORS
Inflammatory cells ENTERAL FEEDINGS
(macrophage) Platelet activating Hypertonic formula or
factor (PAF) Tumor necrosis medication Malabsorption,
factor (TNF) Leukotriene C4, gaseous distention H2 gas
Interleukin 1; 6 production, Endotoxin

9. Symptoms
*Abdominal distention
*Blood in the stool
*Diarrhea
*Feeding intolerance
*Lethargy
*Temperature instability
*Vomiting

10. Physiologic signs Physical signs
• Temperature • Feeding intolerance
instability • Increased gastric residuals
• Apnea • Abdominal distention
• Episodes of • Occult blood/ Hematochezia
Bradycardias & • Peritonitis
Desaturation
• Discoloration of abdominal
• Lethargy
wall
• Acidosis • Abdominal mass
• Thrombocytopenia

11. Severe Abdominal Distension

12. Tests & diagnosis
*Abdominal x-ray
*Stool for occult blood test
*Elevated white blood cell count in a CBC
*Thrombocytopenia (low platelet count)
*Lactic acidosis

13. Radiographic presentation
• X-ray
– Pneumatosis(gas cysts in the bowel wall)
– Dilated loops of bowel
– Portal air
– Free air (if perforated)
• Lateral decub is particularly helpful
• Ultrasound
– Good for bedside demonstration of ascites
– May show portal air more clearly than KUB

14. Radiographic Signs

15. Alimentary tract of infant showing intestinal necrosis, pneumatosis intestinalis, and perforation
site (arrow).

16. Modified Bell Staging for NEC
Stage & Systemic Signs Abdominal Signs Radiographic Signs
Severity
Stage Ia Temp changes, apnea, Distension, gastric Normal, or intestinal
Suspected NEC bradycardia, lethargy retention, emesis, heme dilation
positive stool Mild ileus
Stage Ib Same as Ia Ia + grossly bloody Same as Ia
Suspected NEC stool
Stage IIa Same as Ia Ib + absent bowel Intestinal dilation,
Definite Mild NEC sounds +/- abdominal ileus, pneumatosis
tenderness intestinalis
Stage IIb Ia + mild metabolic IIa + definite IIa + ascites
Definite Moderate NEC acidosis, tenderness, +/- abd
thrombocytopenia cellulitis, RLQ mass
Stage IIIa IIb, but more severe, + IIb + peritonitis, Same as IIb
Advanced, Severe NEC combined respiratory & marked distension and
Bowel Intact metabolic acidosis, tenderness
neutropenia, & DIC
Stage IIIb Same as IIb Same as IIIa IIIa +
Advanced Severe NEC pneumoperitoneum
Bowel Perforated
Adapted from sources showing Bell Staging

17. Prevention
• Encourage breast feeding
– Breast fed babies have lower incidence than formula fed
• No evidence shows that late initiation of enteral
feeding or slow rate of feeding makes any difference
• Maintain high level of suspicion
– Feeding babies with NEC worsens the disease

18. Treatment
•In an infant suspected of having necrotizing enterocolitis,
feedings are stopped and gas is relieved from the bowel by
inserting a small tube into the stomach.
•Intravenous fluid replaces formula or breast milk.
•Antibiotic therapy is started.
•The infant's condition is monitored with abdominal x-rays,
blood tests, and blood gases.
•Surgery will be needed if there is a hole in the intestines or
peritonitis (inflammation of the abdominal wall).
•The dead bowel tissue is removed and a colostomy or
ileostomy is performed.
•The bowel is then reconnected several weeks or months
later when the infection and inflammation have healed.

19. Complications
*Intestinal perforation
*Intestinal stricture
*Peritonitis
*Sepsis

20. Prognosis
•Depends on the severity of the illness
•Necrotizing enterocolitis is a serious disease with a death rate
approaching 25%. Early, aggressive treatment helps improve the
outcome.
•Most infants who develop NEC recover fully and do not have further
feeding problems.
•In some cases, scarring and narrowing of the bowel may occur and
can cause future intestinal obstruction or blockage.
•Another residual problem may be malabsorption (the inability of the
bowel to absorb nutrients normally). This is more common in children
who required surgery for NEC and had part of their intestine removed.

21. THANK YOU!!!!