NEONATAL CONDITIONS
Necrotising Enterocolitis
A practical guide for SCN clinical staff · Inflammatory bowel necrosis of the preterm gut - a neonatal surgical emergency
GUT
EMERGENCY
The vulnerable preterm gut
An immature barrier (leaky tight junctions, thin mucus), immature motility and digestion, and a hyper-reactive innate immune system with high enterocyte TLR4 expression.
Abnormal colonisation
Antibiotics, formula and the NICU environment skew the gut microbiome toward low-diversity, pathogenic gram-negatives (dysbiosis) instead of the protective flora that breast milk and skin-to-skin promote.
Feeding plus ischaemia
Enteral substrate feeds those bacteria, while an ischaemic or hypoxic hit (PDA steal, growth restriction with abnormal Dopplers, hypotension) reduces mucosal perfusion. The two factors interact.
Barrier breakdown & inflammation
Bacteria translocate across the injured mucosa; TLR4 signalling triggers a disproportionate inflammatory response with reduced mucosal blood flow, amplifying the injury rather than containing it.
Pneumatosis & necrosis
Gas-forming organisms produce hydrogen that tracks within the bowel wall (pneumatosis intestinalis) and into the portal veins, while ischaemic-inflammatory injury progresses to full-thickness coagulative necrosis.
Perforation & collapse
Transmural necrosis leads to perforation and peritonitis, and the systemic inflammatory response drives septic shock, DIC and multi-organ failure.
CLINICAL FINDINGS
- Feeding intolerance, increasing gastric residuals, bilious aspirates or vomiting
- Abdominal distension, tenderness, visible loops or discolouration
- Bloody stools
- Systemic: apnoea, bradycardia, lethargy, temperature instability, shock
- Signs of perforation: abdominal rigidity, abdominal wall erythema
INVESTIGATIONS
- Abdominal X-ray (supine + lateral): pneumatosis intestinalis, portal venous gas, fixed dilated loops, free air
- FBC (neutropenia, thrombocytopenia), CRP, blood gas (acidosis), lactate
- Blood culture and coagulation
- Electrolytes - watch for hyponatraemia and metabolic acidosis
- Serial abdominal X-rays to track progression
COMPLICATIONS & RED FLAGS
- Perforation (free air) is a surgical emergency
- Septic shock, DIC and multi-organ failure
- Later strictures, and short bowel syndrome after resection
- Rapid deterioration - keep a low threshold to escalate
- Pneumatosis or portal venous gas confirms NEC - act, do not wait
Abdominal X-ray
The abdominal X-ray is key: pneumatosis intestinalis (intramural gas), portal venous gas, persistently dilated or fixed loops, and free air (Rigler sign, football sign) indicating perforation. A lateral decubitus or cross-table lateral film helps detect free air.
MANAGEMENT
Rest the gut, decompress, give antibiotics and resuscitate; escalate to surgery for perforation or deterioration. Breast milk and standardised feeding are the best prevention.
Medical (Bell I-II)
- Stop enteral feeds; nil by mouth with a large gastric tube on free drainage
- IV fluids/TPN; correct acidosis, electrolytes and perfusion
- Broad-spectrum antibiotics (cover gram-negatives and anaerobes) per local policy, usually 7-10 days
- Serial examinations, X-rays and bloods; provide analgesia
Surgical (Bell III)
- Surgical referral for perforation, deterioration, or a fixed loop/mass
- Options: peritoneal drain, or laparotomy with resection +/- stoma
- Aggressive resuscitation, ventilation and inotropes as needed
- Correct coagulopathy with platelets and blood products
Supportive & prevention
- Promote breast milk and a standardised, cautious feeding regimen
- Probiotics per unit policy
- Monitor for strictures and short bowel during recovery
- Arrange long-term nutrition and growth follow-up
- Watch for early signs - feeding intolerance, bilious or large aspirates, distension, bloody stools, apnoea - and escalate promptly.
- If NEC is suspected: stop feeds, place a large gastric tube on free drainage, and prepare for IV access, bloods and an abdominal X-ray.
- Measure and document abdominal girth, aspirates and stools; handle the tender abdomen gently.
- Prioritise breast milk, follow the unit feeding regimen, and support an anxious family.
Which X-ray findings confirm NEC, and which mandate surgery?
How do breast milk and a standardised feeding regimen reduce NEC risk?
When do you escalate from medical to surgical management?
What are the long-term gastrointestinal consequences for survivors?
Take-home message: NEC is an inflammatory necrosis of the preterm gut, usually in the 2nd-3rd week, presenting with feeding intolerance, distension and bloody stools. Pneumatosis intestinalis on X-ray confirms it; free air means perforation and surgery. Management is nil by mouth, gastric decompression, antibiotics and supportive care, with breast milk and standardised feeding the best prevention.
For educational purposes only. Always align management to current ANZCOR/NRP guidelines and your local SCN/NICU or NETS protocols.