Necrotizing Enterocolitis (NEC)

Question 1

Definition

Answer 1

Syndrome of acute intestinal necrosis of unknown cause usually affects sick prematures with high mortality rate.

Question 2

Risk factors

Answer 2

1. Prematurity
   o The most important risk factor
   o NEC affects 10% of infants < 1500 gm

2. Intestinal ischaemia due to
o Perinatal asphyxia
o Patent ductus arteriosus and indomethacin 
o . Polycythaemia
o Umbilical catheterization

3. Feeding
   o delay feeding
   o Non breast feeding with hyperosmolar formula
   o Aggressive enteral feeding in prematures

Question 3

Pathogenesis

Answer 3

🌷Sloughing and necrosis of the intestinal mucosa especially at terminal ileum and proximal colon

🌷Superadded infection (Klebsiella, E-coli, Clostridia, & Viruses) → Gas formation within the bowel wall → extensive bowel necrosis and Septicemia p perforation & peritonitis

🌼Platelet activating factor, tumor necrosis factor and cytokines may play role

Question 4

Clinical picture

Answer 4

🌺Presentation is usually within 1 st 2 weeks of life A.
🌼. Nonspecific Systemic signs: any combination of the following
Apnea Lethargy Decreased peripheral perfusion Shock (in advanced stages) Cardiovascular collapse Bleeding diathesis (consumption coagulopathy)

🌻Abdominal manifestations
😱Feeding intolerance Delayed gastric emptying Abdominal distention Abdominal tenderness Ileus/decreased bowel sounds Abdominal wall erythema (advanced stages) y Hematochezia

Question 5

Investigations /A. Radiological X-ray

Answer 5

1. X-ray abdomen
   y View: Antero posterior and lateral
   y Should be done and repeated every 8 hours in the first 2 days
   y Findings
   🌝 Pneumatosis-intestinalis (gas in the intestinal wall)
   🌝 Pneumo-peritoneum (gas under the diaphragm) if perforation occurred
   🌝 Intrahepatic portal venous gas

Question 6

Abdominal ultrasound

Answer 6

o Sensitive for pneumatosis-intestinalis but require skilled sonographer
o Doppler of the splanchnic arteries can distinguish very early NEC from benign feeding intolerance in a mildly symptomatic baby

Question 7

Laboratory findings

Answer 7

• Triad of thrombocytopenia, hyponatremia and metabolic acidosis.
• Stool examination for occult blood (Gauiac test).
• Sepsis workup: CBC, CRP and Culture of blood, stool, and CSF

Question 8

Sequalae of NEC

Answer 8

y GI sequelae include strictures, enteric fistulas, short bowel syndrome, malabsorption and chronic diarrhea
y Survivors of NEC have significantly impaired motor and cognitive outcomes

Question 9

Prevention

Answer 9

🌻 Induction of prenatal GI maturation with prenatal corticosteroids
🌻 Standardized enteral feeding guidelines (Avoid aggressive feeding in preterm)
🌻 Exclusive use of human milk.

🌻 Avoidance of acid blockade
🌻 Minimization of empiric antibiotic exposure.

Question 10

Treatment

Answer 10

🌻Admit➡️ To NICU for full monitoring and supportive care

🌻Stop➡️Enteral feedings for 7-14 days according to severity

🌻Start➡️
o GIT rest and nasogastric decompression
o Intravenous fluids / Total Parenteral Nutrition (TPN)
o Broad-spectrum antibiotics for 10-14 days
o Typical combination include:

🌻Support
For respiratory failure (oxygen therapy, ventilation)
For cardiovascular failure(fluid resuscitation, pressors)

🌻Consult
o Pediatric surgeon at the earliest suspicion of developing NEC