Summary

Necrotising Enterocolitis (NEC) is the most common and devastating gastrointestinal emergency in the neonatal intensive care unit. It involves ischemic necrosis of the intestinal mucosa, which can progress to full-thickness perforation, peritonitis, and systemic sepsis. It is primarily a disease of premature infants, characterized by a triad of intestinal ischemia, bacterial colonization, and enteral feeding substrate (formula).

Key Facts

• Definition: Acute inflammatory necrosis of the bowel intestine.
• Demographics: 90% occur in VLBW (<1500g) infants. Incidence is inversely proportional to gestational age.
• Timing: Classic onset is Day 10-14 of life (once full feeds are established). "NEC is a disease of the growing feeder".
• Major Protective Factor: Breast Milk. (Risk is 6-10x higher in formula-fed infants).
• Mortality: 20-30% overall. 50% if surgery is required.
• Long Term: 25% of survivors develop intestinal strictures or Short Bowel Syndrome.

Clinical Pearls

The "Fixed Loop": In early NEC, the gut stops moving (ileus). If you see the exact same loop of gas-filled bowel in the exact same position on X-rays taken 6 hours apart, that bowel is ischemic.

"Red Currant Jelly" Stool: Bloody stool is a late sign. The earliest sign is often just "feed intolerance" or a subtle increase in apneas. By the time the abdomen is black, it is too late.

The Platelet Drop: A sudden drop in platelets (Thrombocytopenia) < 100 in a preterm infant is NEC until proven otherwise. The necrotic gut creates a consumptive coagulopathy (DIC).

Why This Matters Clinically

NEC is unpredictable and catastrophic. A baby can go from "full feeds" to "dead bowel" in 12 hours. Prevention (Breast milk, probiotics, standardized feeding protocols) is the only effective strategy, as treatment is purely supportive or mutilating surgery.

The Modified Bell's Staging Criteria is the gold standard for diagnosis.

Early Signs (Subtle)

• Feed Intolerance: Aspirates >30% of feed volume. Bilious (green) aspirates.
• Apnea/Bradycardia: Often the first sign of sepsis.
• Sugar Instability: Suddenly needs more glucose or becomes hyperglycemic (stress).

Late Signs (Surgical)

• Abdominal Distension: Shiny, tight skin.
• Discolouration: Bluish/Grey hue around umbilicus (Cullen's sign equivalent) or flank redness (Cellulitis of wall).
• Tenderness: Baby flinches/cries on palpation.
• Palpable Mass: An inflammatory phlegmon (matted bowel).

Nursing Care Plan: The "NEC Watch"

What the bedside nurse does (Acute Phase).

Stem Cell Therapy

• Mesenchymal Stem Cells (MSCs): Derived from umbilical cord tissue.
• Mechanism: Potent anti-inflammatory. In animal models, they migrate to the injured gut and prevent necrosis. Phase 1 human trials are underway.

Artificial Womb (Biobag)

• Concept: Keeping extremely preterm fetuses (22-24 weeks) in a fluid-filled environment (no air breathing, no gut feeding needed yet).
• Benefit: Would essentially eliminate NEC by allowing gut maturation before enteral feeding starts.

Amniotic Fluid Administration

• Practice: Giving small amounts of sterile amniotic fluid (Simulated Amniotic Fluid) into the stomach.
• Theory: The fetus swallows amniotic fluid which contains Growth Factors (EGF/G-CSF). Preterms miss out on this.

1. Breast Milk is King

• Contains IgA (coats gut), Lactoferrin (kills bacteria), HMOs (feeds good bacteria), EGF (heals lining).
• Donor Milk: If mother's own milk unavailable, pasteurized donor milk is safer than formula (though less effective than raw maternal milk).

2. Standardized Feeding Protocols

• Slow advancement (15-20ml/kg/day) vs Fast advancement.
• Evidence: Actually, "Slow feeds" probably increase NEC risk because it keeps baby on TPN longer. Protocol compliance is more important than speed.

3. Probiotics

• Evidence: Cochrane reviews consistently show Probiotics (Bifidobacterium/Lactobacillus) reduce NEC risk by 50% in VLBW infants.
• Adoption: Variable. Safety concerns about "probiotic sepsis" (rare).

Probiotic Strains: The Evidence Base

• Lactobacillus rhamnosus GG (LGG): Most studied. Safe.
• Bifidobacterium infantis: Specifically evolved to digest Human Milk Oligosaccharides (HMOs).
• Saccharomyces boulardii: A yeast. Less commonly used in neonates due to fungemia risk.
• Protocol: Start with first feed. Continue until 34 weeks CGA.

4. Antenatal Optimization

Prevention starts before birth.

• Antenatal Steroids: Betamethasone given to mother 24h before delivery matures the fetal gut enzymes as well as the lungs. Reduces NEC risk by 50%.
• Magnesium Sulfate: Neuroprotection also stabilizes hemodynamic flow to the gut.
• Delayed Cord Clamping: Provides extra iron and volume, preventing early anemia/hypoxia.

5. The Fortifier Debate

Does Bovine Fortifier cause NEC?

• Problem: Preterm breast milk lacks enough protein/calcium for growth. We must fortify.
• Risk: Traditional Human Milk Fortifier (HMF) is made from cow's milk. Some studies suggest a slight increase in NEC risk compared to Human-derived HMF (Prolacta).
• Consensus: The growth failure risk from not fortifying outweighs the small theoretical NEC risk. We continue to use HMF, but wait until 100ml/kg feeds are tolerated.

Q: Can I restart breastfeeding? A: Yes! Once the gut heals (usually 10-14 days), breast milk is the best medicine. We start tiny "trophic" feeds (1ml) to teach the gut to work again.

Q: Will my baby need a bag (stoma)? A: If surgery is needed, yes. It is usually temporary. We join the bowel back together outcomes (reversal) when the baby is bigger (2kg+).

Q: What is "Ghost Bowel"? A: Sometimes on X-ray, the bowel looks completely pale/featureless because it has no blood flow. It is a sign of necrosis.