Diagnosis

Necrotizing enterocolitis

Etiology

Cause [zy6][w72]

1. The exact etiology remains unknown

2. Probably multifactorial

   • Prematurity / low birth weight --> gastrointestinal tract immaturity

   • Ischemia and/or reperfusion injury

   • Formula feeding --> Intestinal dysbiosis (abnormal flora)

     • Normal intestinal milieu is enhanced by oligofructose from human milk

3. Prenatal factors associates with NEC

   • Genetic predisposition

   • Chorioamnionitis

   • Intrauterine growth restriction

   • Placenta abruption

   • Preeclampsia

   • Prenatal/perinatal asphyxia

   • Prenatal antibiotics

   • Cesarean section

   • Lack of prenatal steroids

   • Prolonged rupture of membranes

4. Postnatal factors associates with NEC

   • Hypoxia

   • Congenital hearth disease

   • Anemia

   • Decreased intestinal perfusion

   • Patent ductus arteriosus

   • Blood transfusions

   • Medications: antibiotics, indomethacin, H2-blocker

Pathophysiology [zy6]

1. Bacterial invasion into the intestinal wall

2. Proinflammatory intracellular cascades --> Cellular damage/death

3. Necrosis of the colon and intestine

4. Intestinal perforation:

   • Peritonitis

   • Sepsis

   • Death

Complication [zy6]

• Short bowel syndrome (intestinal failure): nutritional deficiencies

• Prolonged total parenteral nutrition --> liver failure

• Postoperative adhesions, stricture and obstruction

• Defects in growth and development

• Multi-organ failure

• Death (mortality rate from 10% up to 50%)

Epidemiology

Incidence per 100.000 [mdm][4sa][kza][riv][7fk][6zv]

Approach

• Blood test: white blood cell count, CRP, hematocrit, platelet count, Na+, K+, and Cl-

• Blood culture

• Blood gas

• Abdominal x-ray: The single most important test

• Abdominal CT

• Abdominal ultrasound

• Paracentesis

• Biopsy

1. Bell's stage 1 (suspected disease): [9wm]

   • Mild systemic disease: apnea, lethargy, bradycardia, fever

   • Mild intestinal signs: abdominal distention, bloody stools

   • Nonspecific or normal radiological signs

2. Bell's stage 2 (definite disease):

   • Mild to moderate systemic signs

   • Additional intestinal signs: absent bowel sounds, abdominal tenderness

   • Specific radiologic signs: pneumatosis intestinalis or portal venous gas

   • Laboratory changes: metabolic acidosis, thrombocytopenia

3. Bell's stage 3 (advanced disease):

   • Severe systemic illness: hypotension, shock

   • Additional intestinal signs: abdominal distention, peritonitis

   • Severe radiologic signs: pneumoperitoneum

   • Additional laboratory changes: acidosis, disseminated intravascular coagulation

Treatment

1. Prevention: breast milk and probiotics [w72][ywg]

2. Standard resuscitation: [zy6]

   • Airway: Reduced consciousness --> Endotracheal intubation

   • Breathing: Respiratory failure --> Mechanical ventilation

   • Circulation: Hypotension --> Fluid resuscitation

3. Supportive care: bowel rest, gastric decompression

   • Stop enteral feedings

   • Nasogastric decompression with intermittent suction

   • Parenteral nutrition

   • Correct electrolyte abnormalities

   • Antibiotics iv: ampicillin, gentamicin, and clindamycin or metronidazole

   • ICU: Inotropic and ventilator support

4. Surgery: worsening condition or bowel perforation

   • Pneumoperitoneum

   • Gas in the portal vein

   • Erythema in the abdominal wall

Differential diagnoses

Aortic coarctation, Appendicitis, Gastroenteritis, Gastrointestinal perforation, Gastroschisis, Hirschsprung's Disease, Infectious colitis, Intestinal atresia, Intestinal malrotation, Intussusception, Meconium ileus, Meningitis, Pneumonia, Pyloric stenosis, Sepsis, Testicular torsion, Tracheoesophageal malformation, Urinary tract infection, Volvulus