• NEC (Necrotizing enterocolitis) is the most common life-threatening GIS disease in the neonatal period. Usually the event is in the terminal ileum, ileocecal region, and right colon.
Etiology
• Prematurity (most common)
• Disruption of intestinal blood flow
- Asphyxia and hypoxic ischemic injury
- Umbilical vein or artery catheterization
- PDA
- Polycythemia
- Hypotensive states.
• Enteral nutrition (excessive and rapid volume increase), early feeding with hyperosmolar formula.
• Bacterial colonization: The microorganisms most commonly isolated in necrotizing enterocolitis; E.coli, K. pneumonia, S. epidermidis, Clostridium perfringens and some viruses (Astrovirus, Norovirus, Enterovirus, Koronavirus, Rotavirus).
• Down syndrome, congenital heart diseases, Hirschsprung's disease, asphyxia and rotavirus increase the risk of NEC.
Clinical findings
• Symptoms usually begin between the 3rd and 10th days.
• The earliest findings in NEC are nonspecific lethargy and body temperature imbalance or abdominal distention and gastric retention in the gastrointestinal tract. In the late period, crepitation due to gas in the intestinal wall can be taken. Enlarged bowel loops can be seen or felt by palpation. Sometimes the mass is palpable, the abdomen is tender, there may be ascites, edema in the abdominal wall. There may also be a blood sugar imbalance. Shock, perforation, and peritonitis indicate advanced stages.
Pathological changes in necrotizing enterocolitis are usually in the terminal ileum, ileocecal region, and proximal colon.
Radiological findings
• The earliest radiological finding is enlarged bowel loops and distension. Air-fluid level is detected in a small number of cases.
• The presence of intramural gas (pneumatosis intestinalis) is typical. Gas bubbles can also be seen in the liver on ultrasonography.
• Gas in the portal vein (pyopneumophlebitis) indicates a poor prognosis.
Lab
• The most common laboratory findings; metabolic acidosis, anemia, thrombocytopenia, leukopenia, electrolyte disorders, occult blood and reductant positivity in stool, disseminated intravascular coagulation in severe cases.
NEC Clinical manifestations and evaluation
Early
- Increased gastric residue, abdominal distension
Suspicion of NEC (Necrotizing enterocolitis) (minimal
evaluation):
Complete blood count and peripheral smear
Abdominal film, repeat if necessary
Platelet count
Look for blood and reducing substance in the stool
- Positive occult blood in stool
Suspicion of severe NEC (Necrotizing enterocolitis):
Complete blood count and peripheral smear
Abdominal film at least every 8 hours
Platelet count 1-2 times a day
- Hematemesis
If platelets are low, check PT and PTT.
Check arterial blood gas 1-2 times a day to detect acidosis.
- Lethargy (septic appearance), hyperthermia, apnea etc.
electrolytes
Late
- Abdominal tenderness or erythema
Documented NEC (Necrotizing enterocolitis):
Complete blood count and peripheral smear
Abdominal X-ray every 6 hours during acute illness
- Gross gastrointestinal bleeding
Platelet count twice daily and PT if low, PTT
Check arterial blood gas 1-2 times a day to detect acidosis.
- Shock with septic appearance
electrolytes
Treatment
I. Resting the bowel
2. Treatment of infection
3. Keeping the baby alive until the intestine heals.
Other main principles of treatment are: discontinuation of oral intake, nasogastric decompression, monitoring of vital signs and abdominal circumference, removal of umbilical catheters, broad-spectrum antibiotic therapy, gastrointestinal bleeding monitoring, monitoring of intake and withdrawal. For this purpose, total parenteral nutrition (TPN) is applied for 7-10 days.
Absolute surgical indication; It is a perforation finding on abdominal X-ray.
Relative surgical indications; Delay in healing with medical treatment, single fixed intestinal loop on X-ray, erythema and induration in the abdominal wall or palpable mass in the abdomen.
Peritoneal drainage can be applied instead of open laparotomy in newborns who are unstable, have poor general condition and are not suitable for surgical intervention.
Protection
• Breast milk is protective. Minimal enteral nutrition is extremely important. There are studies showing that probiotics are beneficial. Gastric acid secretion-reducing agents and unnecessary long-term empirical antibiotic use should be avoided.
