necrotizing enterocolitis

1. NECROTIZING
ENTEROCOLITIS
 Dr. Devendra Nargawe

2. • Necrotizing enterocolitis is the most
common serious surgical emergency in
NICU.
• NEC occurs in 2- 5 % of all NICU admission
and 5-10% of VLBW infants.

3. ETIOLOGY
• It is probably multifactorial . There are several
associated factors including:
• Prematurity
• Rapid advances in feeding of ELBW infants.
• Asphyxia
• PDA
• Umbilical artery cath. Tip at or above the mesenteric
artery.
• Indomethacin / ibuprofen
• Aminophylline
• Polycythemia
• Hypothermia

4. PATHOGENESIS
Perinatal
hypoxia
Umbilical vessel
catheterization
Vasospasm
thrombo- embolic
phenomena
Bacterial invasion
Toxins
(neuraminidase)
Hypovolemia
(shock)
Preterm baby
Diving reflex
(mesenteric
vasospasm)
Reduced
intestinal
perfusion
Ischemic mucosal injury
Direct mucosal damage
Low cardiac
output
Hypothermia
Blood loss
Septicemia
Exchange
transfusion
Type and amount
of feeds
Hyperosmolar
feeds
Intestinal stasis

5. CLINICAL FINDINGS
• Feeding residuals ( coffee ground aspirates)
• Abdominal distension
• Constipation
• Blood in the stool
• Erythema of abdominal wall ( when peritonitis is present)
• Lethargy or other non-specific signs of infection
* Data from PGIMER shows that the peak age for NEC in
preterm infants is from end of the 1st week of life to the 2nd
week

6. STAGING
• A staging devised by Bell and letter modified by Walsh
AND Kleighman is useful for therapeutic decisions .
Stage Systemic
sign
Intestinal signs Radiologica
l signs
Rx
Ia suspected
NEC
Temp.
instability,
apnea,
bradycardia
, lethargy
Elevated pre
lavage residual,
mild abdominal
distension ,
emesis , guaiac
positive stool
Normal or
intestinal
dilatation,
mild ileus
NBM,
antibiotics
for 3 days
Ib suspected
NEC
--do-- Bright red blood
from rectum
Do Do

7. Stage Systemic sign Intestinal
signs
Radiological
signs
Rx
II a definite
NEC ,
mildly ill
Temperature
instability,
apnea,
bradycardia,
lethargy
Absent bowel
sounds ,
abdominal
tenderness
Intestinal
dilatation,
ileus,
pneumatosis
intestinalis(
small gas
bubble in
bowel loops)
NBM ,
antibiotics
for 7-10
days
II b definite
NEC
moderately
ill
Do plus mild
metabolic
acidosis
Do plus
definite
abdominal
tenderness
+/-
abdominal
cellulitis or
right lower
quadrant
mass
Same as II a
plus portal
vein gas +/-
ascites
NBM,
antibiotic
for 14 days ,
NaHCO3
for acidosis

8. Plain abdominal x-ray on the left showed pneumatosis intestinalis (large arrow), a specific
characteristic finding in necrotizing enterocolitis (NEC). X ray on the right is a follow-up
film which showed free air indicating the perforation of the bowel (small arrow)

9. Stage Systemic
sign
Intestinal
signs
Radiological
signs
Rx
III a advanced
NEC severely
ill , bowel
intact
Same as II b
plus
hypotension,
bradycardia,
apnea,
combined
respiratory and
metabolic
acidosis, DIC,
neutropenia
Same as
above plus
signs of
generalized
peritonitis,
marked
tenderness
and distension
of abdomen
Same as IIB plus
definite ascites
Same plus
more fluid
abd.
Paracentesis
Inotropic
agents,
ventilation
III b advanced
NEC severely
ill , bowel
perforated
Same as III a Same as III a Same as II b plus
pneumoperitonium
Same +
abdominal
surgery

12. LABORATORY FINDINGS
• Thrombocytopenia
• Hyponatremia
• Metabolic acidosis
• Evidence of DIC
• overt or occult blood in the stool
• Urine should be examined for hyphae and budding
yeast to rule out systemic candidiasis.
• Blood and stool culture are mandatory

13. DIFFERENTIAL DIAGNOSIS
• infectious enterocolitis – diarrhea with blood in stool
• Candidemia –may mimic early features of NEC
• Sepsis and pneumonia may cause ileus without NEC.
• Gut immaturity
• Congenital intestinal obstruction
• Spontaneous intestinal obstruction
• Intussusception
• Dysentery
• Campylobacter diarrhea

14. APPROACH TO CASE OF SUSPECTED NEC
Suspected NEC
NBM, continuous gastric aspiration, antibiotics, complete work up
for sepsis, platelet count, stool for occult blood, ABG, electrolytes,
AXR, remove umbilical cath.
Stage 3 disease
Yes
Pediatric Sx opinion and
abdominal paracentesis
Perforation
Flank discharge
No
improvement
in next 48h
Laparotomy
No
Continue supportive
care in all stages

15. MANAGEMENT
• General considerations
• Avoid or minimize factors which may contribute to bowel
ischemia.
• Maintain a high level of suspicion , when advancing
feedings in very low birth weights baby.

16. MEDICAL MANAGEMENT
• Stop enteral feeds and oral medications
• Duration of NBM
• Stage 1 : 3 days
• Stage 2 : 7-10 days
• Stage 2b & 3 : 14 days
Keep the GIT decompressed using 8 -10 F NGT. Replace the
aspirate with N/2 saline with KCL every 8 hours.
• IV fluids
• Give normal maintenance for stage I and II
• In stage III , more than 200ml/kg/day may be required
due to 3rd space losses.

17. OTHER MEASURES
• Maintain adequate tissue perfusion using
symapathomimetic agents. (dopamine 5-8
microgram/kg/min)
• Give plasma or blood transfusion as required
• Inj. Vit. K if bleeding or if not given in last 1 week
• Correct metabolic acidosis
• Start antibiotics as per culture report
• Duration of therapy
• Stage I : 3 days (depending on culture)
• Stage II : 7 to 10 days
• Stage III : 14 days

18. MONITORING
• Aggressive monitoring forms a corner stone for successful
outcome
1. Clinical
• Abdominal girth
• Gastric aspirate – quantity and nature 1-2 hourly
• CRT, BP, RR, HR, and PaO2
2. Radiological
• Initially 8 hourly x-ray abdomen during the first 48 to 72 hours,
thereafter once daily.
3. Laboratory
• Hematocrit and blood glucose 8 hourly
• Serum Na+/ K+ : 12 hourly
• Platelet count and neutrophil count once initially and then 48
hrs. later
• ABG 12 hourly during the initial 48 to 72 hours

19. SURGICAL MANAGEMENT
• Indications
• GI perforation
• Full thickness necrosis
• Peritonitis

20. • Features which suggestive perforation/ full thickness
necrosis are:
• Pneumoperitonium
• Positive abdominal paracentesis
• Portal venous gas on plain x-ray
• Abdominal wall erythema / induration
• Fixed loop on serial radiographs
• Supportive evidence:
• Abdominal tenderness
• Thrombocytopenia ( <1,00,000/ cu. Mm)
• Clinical deterioration
• Severe GI hemorrhage

21. COMPLICATIONS
• Short term
• Irreversible shock
• Extensive bowel infraction
• secondary infection ( usually with enteric organism or
staph. )
• Long term
• Intestinal stricture and bowel obstruction
• Short bowel syndrome ( after bowel resection)

22. PROGNOSIS
• It depends upon
• Severity of illness
• Amount of bowel removed
• Associated complications

23. PREVENTION
• Delay enteral feeding in stressed preterm infants who
have suffered hypoxic ischemic episodes.
• Avoid rapid increases in the volume of feeds
• Treat polycythemia aggressively.
• Do not feed preterm with PDA
• Stop feeds with bilious aspirate or continuous large
gastric aspirates
• Do not feed during dopamine infusion
• Prophylactic probiotics reduce severe NEC by 66%. 1
sachet 12 hourly for 21 days for all neonates weighing
<1250 gm at birth .

24. RE FE RE NCE
• Care Of Newborn – Meherban Singh
• PGI NICU HANDBOOK OF PROTOCOLS; 4th edition 2010
• Handbook of Neonatology ; Dr Hemant Jain
• Manual of newborn care ; 7th edi. John p. cloherty