Pediatric surgery in the neonatal period. Major surgical emergency

1. NECROTIZING
ENTEROCOLITIS
(NEC)
PRESENTER: DR. SHILULI MATE
FACILITATOR: DR. PHILLIPE

2. OUTLINE
• Definition
• Epidemiology
• Risk factors & etiology
• Pathogenesis
• Clinical presentation
• Investigation
• Management
• Prognosis

3. DEFINITION
• Death & necrosis of intestinal tissue
• Characterized by variable damage to the intestinal tract,
ranging from mucosal injury to full-thickness necrosis &
perforation
• Typically occurs in the 2nd - 3rd week of life in premature &
formula-fed infants. Occurs early in term infants (1-3days)

4. EPIDIMIOLOGY
• Most common GI medical/surgical emergency in
newborns
• Incidence is 3/1000 live births,
– 3/100 live birth in LBW
• 90% are premature
• Male: Female 1:1
• Blacks ˃ Whites

5. RISK FACTORS
• Prematurity ˂ 34 weeks
• LBW ˂ 1500g (approx. 10% )
• Term infant with pre-existing illness
• Enteral feeding of premature infants
– Hypertonic formula/enteral meds
– Breast milk protective compared to formula
NB : Rate of feeding & timing of initiation of feeds don’t change
rates of NEC

6. ETIOLOGY
• Exact cause not known
• Multifactorial: ischemia &/or reperfusion injury, exercabated by activation
of pro-inflammatory intracellular cascades
• Premature have immature bowels, weakened by low oxygen or blood flow
• Early feeding causes more stress to the lumen allowing bacteria that are
normally found in the intestine invade & damage the mucosa

7. Etiology cont.…
• The damage can affect a small segment of the
intestine or progress to affect a larger portion
• Common enteric pathogens: E. coli, Klebsiella, C.
perfiringes, S. epidermidis & rotavirus

8. PATHOGENESIS
• Multiple risk factors predispose to getting NEC
• An insult to the intestinal lumen initiates the
process
• Progression is due to stasis, vascular factors &
bacterial overgrowth
• May resolve or may progress to perforation

10. CLINICAL PRESENTATION
• History: Maternal risk factors – infections, PET, DM, drug abuse…
• Initial symptoms:
– Vomiting & diarrhea
– Delayed gastric emptying
– Feeding intolerance
– High gastric residuals
– Abdominal distension
– Frank occult blood in stools

11. Physical examination
• GI signs:
– Erythema of the abdominal wall
– Increased abdominal girth
– Visible intestinal loops
– Abdominal distention
– Change in stool patterns
– Hematocheza
– Palpable abdominal mass
– Reduced bowel sounds

12. PE cont.…

13. Systemic signs:
• Advanced disease will present with signs & symptoms
of:
– Respiratory failure - apnea
– Decreased peripheral perfusion
– Circulatory collapse - bradycardia
– Consumptive coagulopathy – bleeding diathesis
– Lethargy
– Temperature instability

14. DIFFERENTIAL DIAGNOSIS
• Intestinal malrotation
• Intestinal volvulus
• Bacterial meningitis
• Neonatal sepsis
• Ompahlitis
• Prematurity
• Volvulus
• UTI
• Apnea of prematurity

15. INVESTIGATIONS
• CBC: ↑WBC, ↓ANC ↓RBC, ↓PLT,
• Blood culture: Isolate the causative organisms
• Serum electrolytes: ↓Na,
• Stool: Occult blood
• ABG: ↓serum bicarbonate (˂20mEq/l), lactic
acidosis

16. Abdominal Imaging
• Mainstay diagnostic is plain abdominal x-ray
• Plain abdominal x-ray features for NEC:
– Pneumatosis intestinalis (gas cyst in the bowel wall) –
pathognomic of NEC
– Dilated loops of bowel
– Portal air – poor prognostic sign
– Free air (if perforated) – lat. decubitus view

17. Abdominal x-ray

18. Abdominal ultrasound
• Good for bedside demonstration of ascites
• May show portal air more clearly than KUB

19. Modified Bells Staging for NEC

20. MANAGEMENT
• Initial course of treatment entails
– Nil per oral – stop all enteral feeds
– Decompression – NGT
– Initiate broad-spectrum antibiotics (ampicillin,
aminoglycoside, or 3rd generation cephalosporin &
clindamycin or metronidazole
– IVF
• The definitive treatment approach will depend
on the stage:

21. Treatment cont..
Stage IA & 1B:
• NPO
• Antibiotics for 3/7
• IVF, including TPN
Stage IIA & IIB:
• NPO & TPN
• IVF resuscitation for RS & CVS support
• Antibiotics for 2/52
• Surgical consult

22. Treatment cont.…
Stage IIIA &B III:
• NPO & TPO for 2/52
• IVF resuscitation
• Inotropes
• Ventilatory support
Stage IIIB:
• Surgery - indicated for perforation &/or peritonitis

23. Treatment cont…
• Surgery involves:
– Resection of necrotic tissue
– Colostomy/ileostomy performed
– Anastomosis of bowel segments done after
infection is eradicated

24. COMPLICATIONS
• Intestinal perforation
• Intestinal strictures
• Peritonitis
• Sepsis
• Malabsorption

25. Prognosis
• Depends on severity of the illness
• Death rate approximates 25%
• Early aggressive treatment improves the outcome
• Most infants recover fully & never have feeding
problems
• Few cases can resulting bowel narrowing and scarring
causing further obstruction/blockage

26. References
1. Williams, N. S., Bulstrode, C. J., &
O'Connell, P. R. (2008). Bailey & Love's
short practice of surgery. Crc Press.
2. Medscape
3. Slideshare