Necrotizing enterocolitis (NEC) is a life-threatening emergency of the gastrointestinal tract in the newborn period. The most common gastrointestinal condition in premature neonates. It is characterized by inflammation, ischemia, and permeability of the neonatal bowel wall to bacteria. It is potentially life-threatening with significant associated morbidity. The disease is characterized by various degrees of mucosal or transmural necrosis of the intestine.

1. NECROTIZING ENTEROCOLITIS
IN NEONATES
Dr Samson Ojedokun
MB;BS Ogbomoso Nigeria

2. Outline
• Introduction
• Epidemiology
• Pathogenesis
• Clinical presentation
• Investigations
• Treatment
• Differential diagnosis
• Prognosis
• Complications
• Preventions
• Conclusion

3. Introduction
• Necrotizing enterocolitis (NEC) is a life-threatening emergency of the
gastrointestinal tract in the newborn period.
• The most common gastrointestinal condition in premature neonates.
• It is characterized by inflammation, ischemia, and permeability of the
neonatal bowel wall to bacteria.
• It is potentially life-threatening with significant associated morbidity.
• The disease is characterized by various degrees of mucosal or
transmural necrosis of the intestine.

4. Epidemiology
• Globally, incidence varies between 0.3 to 2.4 infants per 1000 live
births.
• Nearly 70% of these cases occur in premature infants
• Mortality ranges from 10% to 50% and almost 100% in the most
severe cases, involving perforation, peritonitis, and sepsis
• Both incidence and case fatality rates increase with decreasing birth
weight and gestational age

5. • A systematic review of 27 cohort studies reported that 39,965
developed NEC of 574,692; a global prevalence of 7%
• It ranges between 2.50% and 4.53% in China
• It affects 5-12% reported in Canada
• In Egypt 9.7-16.4% neonates were diagnosed with NEC
• In Nigeria NEC contributes 11.8% to neonatal death

6. Risk factors

7. Diagram showing predisposing factors for NEC

8. Pathogenesis
• The disease is characterized by various degrees of mucosal or
transmural necrosis of the intestine.
• The cause of NEC remains unclear but is most likely multifactorial.
• Clustering of cases suggests a primary role for an infectious agent.
• Various bacterial and viral agents, including Escherichia coli,
Klebsiella, Clostridium perfringens, Staphylococcus epidermidis,
astrovirus, norovirus, and rotavirus, have been recovered from
cultures.
• Nonetheless, in most situations, a pathogen is not identified.

11. Presentation
• The onset of NEC is usually in the 2nd or 3rd week of life but can be
as late as 3 months in VLBW infants. Age of onset is inversely related
to gestational age.
• Compared with a preterm infant, a term baby with NEC presents at a
younger age, with a reported median age of onset that ranges from 1-
3 days of life in the immediate postnatal period
• Infants with NEC have a variety of signs and symptoms and may have
an insidious or sudden catastrophic onset.

12. GIT
• diarrhea,
• feeding intolerance
• Delayed gastric emptying
• abdominal distention
• frank or occult blood in
stools.
• abdominal tenderness
• abdominal wall erythema
• palpable bowel loops.
Systemic
• apnea
• bradycardia
• lethargy
• labile body
temperature
• hypoglycemia
• rapid cardiovascular
and hemodynamic
collapse
• shock

13. • Bloody stools are seen in 25% of patients.
• Other examination findings may include visible intestinal loops,
decreased bowel sounds, respiratory failure, circulatory collapse,
cyanosis and unresponsiveness
• The spectrum of illness is broad, ranging from mild disease to severe
illness with bowel perforation, peritonitis, systemic inflammatory
response syndrome, shock, and death.

14. Investigations
• Plain abdominal radiographs
• Abdominal ultrasound
• Laboratory assays

15. Plain Abdominal X-ray findings include:
• Dilated bowel loops (often asymmetrical in distribution)
• Loss of the normal polygonal gas shape
• Bowel wall edema with thumbprinting
• Pneumatosis intestinalis (pathognomonic)
• Pneumoperitoneum-football sign (severe disease)
• Air on both sides of the bowel (Rigler sign)
• Visible free gas

16. Radiographs showing pneumatosis intestinalis

17. Radiographs showing Football sign

18. Ultrasound features
• bowel wall thickening
• alteration of the vascular state
• hypervascular (viable but engorged in early stage)
• hypovascular (infarcted in a later stage)
• intramural gas manifesting as hyperechoic foci within the bowel wall
• free fluid, especially with echogenic debris, suggesting perforation
• Portal venous gas (severe disease)

19. Laboratory investigations
• WBC – Moderate to profound neutropenia (absolute neutrophil count
< 1500/μL) strongly suggests established sepsis
• Hematocrit and hemoglobin – Blood loss from hematochezia and/or a
developing consumptive coagulopathy can manifest as an acute
decrease in hematocrit; an elevated hemoglobin level and hematocrit
may mark hemoconcentration due to notable accumulation of
extravascular fluid
• Platelet count – Thrombocytopenia may be present

20. • Blood culture is usually negative
• Hyponatremia – An acute decrease in serum sodium (< 130 mEq/dL)
is alarming
• Low serum bicarbonate (< 20) may be seen in babies with poor tissue
perfusion, sepsis, and bowel necrosis
• Arterial blood gas levels may indicate needs for respiratory support
and can provide information on the acid-base status
• Stool occult blood test is also essential

21. Staging of NEC
• The Bell system is the staging system most commonly used to
describe necrotizing enterocolitis (NEC).

23. Treatment
Supportive care
• Cessation of feeding
• Nasogastric decompression
• Administration of intravenous fluids
• Total parenteral or intravenous nutrition
• Systemic antibiotics (with broad coverage such as ampicillin,
cefotaxime, gentamicin, or metronidazole, or vancomycin) should be
started immediately.

24. • If present, umbilical catheters should be removed
• Ventilation should be assisted in the presence of apnea or if
abdominal distention contributes to hypoxia and hypercapnia.
• correction of hematologic, metabolic, and electrolyte abnormalities.
• Gown and glove isolation and grouping of infants at similar increased
risks into cohorts separate from other infants to contain an epidemic.

25. Surgical care
• Failure of medical management
• Perforation on abdominal x-ray (pneumoperitoneum)
• A single fixed bowel loop on radiographs, abdominal wall erythema,
and a palpable mass are relative indications for exploratory
laparotomy.

26. Differential diagnosis
• Specific infections (systemic or intestinal),
• Gastrointestinal obstruction
• Intestinal Volvulus
• Isolated intestinal perforation

27. Prognosis
• Depends on the severity at the time of diagnosis and initiation of
treatment.
• Medical management fails in approximately 20-40% of patients with
pneumatosis intestinalis at diagnosis; of these, 10-30% die.
• Postoperative complications include wound infection, dehiscence,
and stomal problems (prolapse, necrosis).
• In advanced NEC with full-thickness destruction of the intestinal wall
which leads to perforation and peritonitis, mortality approaches
100%.

28. Complications
• Intestinal strictures
• Short bowel syndrome (malabsorption, growth failure, malnutrition),
• Intestinal failure
• Nutritional deficiencies
• Associated defects in growth and development
• Complications related to central venous catheters (sepsis, thrombosis), and
cholestatic jaundice.
• Prolonged total parenteral nutrition, which may lead to liver failure
• Postoperative adhesions and scarring may lead to stricture and obstruction

29. Prevention
• Health education
• Early presentation
• Proactive treatment
• Prevention of complications
• Rehabilitation

30. Conclusion
• Necrotizing enterocolitis is a devastating inflammatory disorder found
mostly in preterm neonates and associated with high morbidity and
mortality rates.
• Despite incremental advances in understanding of the clinical
presentation and pathophysiology of NEC, universal prevention of this
disease continues to elude clinicians even in the twenty-first century.
• A high index of suspicion is required for early diagnosis to prevent its
rapid progressive nature and enhance good outcomes

31. References
• Akhil Maheshwari and Waldemar A. Carlo, Nelson Textbook of Pediatrics 20th
Edition pg 869-871
• Alsaied, A., Islam, N., & Thalib, L. (2020). Global incidence of Necrotizing
Enterocolitis: A systematic review and Meta-analysis. BMC Pediatrics, 20(1), 1–15.
• Ugwu RO, Okoro PE. Pattern, outcome and challenges of neonatal surgical cases
in a tertiary teaching hospital. African Journal of Paediatric Surgery.
2013;10(3):226.
• Bell, D., & Weerakkody, Y. (2009). Necrotising enterocolitis. Radiopaedia.Org.
https://doi.org/10.53347/RID-7658
• Derbew Bahir, W., Girma, F., Dagnew, A. B., Derbew, W., & Girma, F. (2021).
Determinants of necrotizing enterocolitis among neonates in referral hospitals of
East and West Gojjam zones Northwest, Ethiopia, 2020.
• Lopes, R. B., Moreira, M. E. L., & Hermeto, F. (2023). Necrotizing Enterocolitis.
Perinatology: Evidence-Based Best Practices in Perinatal Medicine, 1215–1228.
• Necrotizing Enterocolitis Workup: Approach Considerations, Abdominal
Radiography. https://emedicine.medscape.com/article

32. Thank You