Makindo Medical Notes

⚠️ Necrotising Enterocolitis (NEC) affects ~5% of infants with birth weights <1,500g. It often presents with abdominal distension, bloody stools, bile-stained vomiting, and the classic radiological finding of pneumatosis intestinalis.

🍼 About

• NEC is a life-threatening gastrointestinal emergency, almost exclusively affecting premature neonates.
• It can lead to bowel perforation, peritonitis, septic shock, and death.
• Mortality remains high (20–30%), especially with advanced disease.

⚡ Aetiology & Pathophysiology

• Immature intestinal mucosa + impaired barrier function.
• Combination of ischaemia–reperfusion injury, bacterial invasion, and an exaggerated inflammatory response.
• Inflammatory mediators (PAF, TNF, cytokines) → necrosis of intestinal wall.

📌 Risk Factors

• Prematurity & very low birth weight (VLBW).
• Formula feeding ❌ (breastfeeding protective).
• Congenital heart disease (↓ mesenteric perfusion).
• Polycythaemia, PDA, or use of umbilical arterial catheters near mesenteric arteries.
• Medications: Indomethacin, steroids (with indomethacin).
• Maternal factors: Cocaine exposure, perinatal hypoxia.

🩺 Clinical Presentation

• Feeding intolerance or bilious vomiting 💚.
• Abdominal distension, tenderness, wall oedema, or palpable mass.
• Blood-stained stools 💩.
• Absent bowel sounds, shock, apnoea, bradycardia in severe disease.
• Signs of perforation → rigid abdomen, peritonitis, rapid collapse.

🔬 Investigations

• Bloods: ↑ WCC/CRP, ↑ lactate, thrombocytopenia, coagulopathy (DIC).
• U&E: AKI, hyponatraemia.
• Blood gas: Metabolic acidosis (classic).
• AXR: Pneumatosis intestinalis (gas in bowel wall), portal venous gas, free air (if perforation).

📊 Staging – Bell’s Criteria

Stage	Clinical Features	Investigations
Stage I (Suspected)	Feeding intolerance, abdominal distension, occult/visible blood in stool, apnoea, bradycardia	AXR: non-specific, mild distension
Stage II (Definite)	Absent bowel sounds, tenderness, systemic illness	Pneumatosis intestinalis or portal venous gas, metabolic acidosis, thrombocytopenia
Stage III (Advanced)	Severe illness, peritonitis, shock, DIC	Pneumoperitoneum = perforation

🛠️ Management

• Resuscitation: ABC, fluids, correct acidosis, oxygen/ventilation if needed. Morphine for pain.
• Medical (first-line in suspected/early cases):
  • Nil by mouth (NBM) 🚫🍼
  • IV fluids & TPN
  • Broad-spectrum IV antibiotics
  • NG tube for decompression
• Surgical:
  • Consult urgently if pneumoperitoneum, peritonitis, or clinical deterioration.
  • Options: bowel resection ± stoma, or peritoneal drain in VLBW infants.
• Special situations: Avoid indomethacin in PDA with NEC. Consider PDA closure surgically.

⚠️ Complications

• Sepsis & peritonitis → multiorgan failure.
• Intestinal strictures (esp. colon).
• Short bowel syndrome → prolonged TPN dependence.

📚 References

• UCSF Manual – Necrotising Enterocolitis

Cases — Necrotising Enterocolitis (NEC) 👶🩺

• Case 1 — Preterm Baby with Distended Abdomen 🌡️: A 28-week preterm infant, day 10 of life, develops abdominal distension, bilious gastric aspirates, and bloody stools. Exam: tender abdomen, reduced bowel sounds. Abdominal X-ray: pneumatosis intestinalis. Diagnosis: NEC in very preterm infant. Management: Stop enteral feeds (NPO), NG decompression, IV antibiotics, supportive fluids; surgical review if perforation.
• Case 2 — Term Baby with Congenital Heart Disease 💔: A 3-day-old term neonate with hypoplastic left heart syndrome develops abdominal distension and fresh blood per rectum after formula feeding. CXR: portal venous gas. Diagnosis: NEC in term infant, precipitated by poor gut perfusion (CHD). Management: Supportive (IV fluids, antibiotics, NPO), optimise cardiac status, surgical team involvement if perforation/peritonitis suspected.
• Case 3 — Complicated NEC with Perforation ⚠️: A 2-week-old preterm neonate suddenly deteriorates with apnoea, abdominal wall erythema, and shock. Abdominal X-ray: free intraperitoneal air. Diagnosis: NEC complicated by intestinal perforation and peritonitis. Management: Emergency surgical intervention (laparotomy ± resection), broad-spectrum antibiotics, intensive care support.

Teaching Commentary 🧠

NEC = acute intestinal necrosis, mainly in preterm neonates. - Risk factors: prematurity, formula feeding, hypoxic/ischaemic events, congenital heart disease. - Clinical features: feeding intolerance, abdominal distension, bloody stools, sepsis. - Key radiology: pneumatosis intestinalis (air in bowel wall), portal venous gas, free air (perforation). - Management: Stop feeds, NG decompression, broad-spectrum antibiotics, fluid resuscitation, surgical referral if perforation/necrosis. ⚠️ Mortality is high; survivors may develop short bowel syndrome or strictures.