Necrotizing Enterocolitis (NEC)

Necrotizing enterocolitis is a severe gastrointestinal disease primarily affecting premature and low birth weight infants.

Necrotizing enterocolitis (also called NEC) causes inflammation of intestinal tissue, which can cause the tissue to die. A hole can form in the intestine, allowing bacteria to leak into the bloodstream.

Necrotizing enterocolitis can be a serious, life-threatening problem. Some babies may require surgery to remove the damaged intestine.

Learn more about necrotizing enterocolitis, including its definition, causes, symptoms, diagnosis, treatment, and potential risks and complications.

What is necrotizing enterocolitis (NEC)?

Necrotizing enterocolitis (NEC) is an inflammatory disease that leads to the death of tissues in the intestines. NEC primarily impacts the small and large intestines. The disease commonly occurs in premature infants, typically within the first few weeks of life. NEC can cause a range of symptoms, from mild feeding intolerance to severe systemic illness, and can lead to significant morbidity and mortality.

Causes of necrotizing enterocolitis

Necrotizing enterocolitis is more common in premature infants. These babies typically have weaker immune systems, making it more difficult for them to fight off infections. Premature infants may also have underdeveloped bowels that are more susceptible to injury and infection. Reduced blood flow to the intestines (called ischemia) can damage the intestinal tissue, leading to necrosis.

Other risk factors

• Infections: Systemic infections can increase the risk of developing NEC.
• Congenital heart disease: Infants with heart defects may have compromised blood flow to the intestines, increasing the risk of NEC.

Symptoms of necrotizing enterocolitis

Necrotizing enterocolitis most often occurs within a few weeks of birth. Symptoms may occur suddenly in babies who are otherwise healthy.

Symptoms may include:

• Feeding intolerance: Difficulty feeding and increased gastric residuals.
• Abdominal distension: Painful swelling or bloating of the abdomen.
• Bloody stools: Presence of blood in the stool, often a sign of intestinal injury.
• Vomiting: Green or yellow bilious vomiting.
• Lethargy: Unusual tiredness and lack of energy.
• Temperature instability: Difficulty maintaining a normal body temperature.
• Apnea and bradycardia: Episodes of stopped breathing and slow heart rate.
• Poor perfusion: Pale, mottled skin indicating poor blood flow.

Diagnosis of necrotizing enterocolitis

To diagnose necrotizing enterocolitis, a health care provider may use tests including:

• Symptom assessment: Detailed inquiry about feeding difficulties, abdominal distension, bloody stools, and systemic symptoms.
• Physical examination: Examination of the abdomen to detect signs of distension, tenderness, and bowel sounds.
• Abdominal X-rays: Imaging to look for signs of NEC, such as pneumatosis intestinalis (air within the intestinal wall), portal venous gas, and free air indicating perforation.
• Blood tests: Complete blood count (CBC), blood cultures, and inflammatory markers (C-reactive protein) to assess for infection and inflammation.
• Stool tests: Testing for blood and bacterial cultures in the stool.
• Ultrasound: Additional imaging to assess bowel perfusion and detect complications like abscesses.

Treatment of necrotizing enterocolitis

Medical management

• NPO (nil per os): Stopping all oral feedings to rest the bowel and prevent further injury.
• Parenteral nutrition: Providing nutrients through an intravenous (IV) line to ensure adequate nutrition and growth while allowing the intestines to heal.
• Antibiotics: Broad-spectrum antibiotics to treat and prevent bacterial infections.
• IV fluids: Administration of fluids to maintain hydration and electrolyte balance.

Supportive care

• Respiratory support: Oxygen therapy or mechanical ventilation if necessary due to respiratory distress.
• Thermoregulation: Maintaining a stable body temperature using incubators or warmers.
• Monitoring: Close monitoring of vital signs, abdominal girth, and overall clinical status.

Surgical treatments

• Exploratory laparotomy: Surgical intervention may be required if there is evidence of intestinal perforation, severe necrosis, or failed medical management.
  • Bowel resection: Removing the necrotic or perforated segments of the intestine.
  • Enterostomy: Creating a temporary stoma (opening) to divert stool and allow the intestines to heal.
• Peritoneal drainage: Less invasive option for critically ill or unstable infants, involving placement of a drain into the abdominal cavity to relieve pressure and remove infected fluid.

Potential risks and complications

Complications of untreated NEC

• Intestinal perforation: Rupture of the bowel leading to peritonitis, a life-threatening infection of the abdominal cavity.
• Sepsis: A severe systemic infection that can lead to septic shock, organ failure, and death.
• Strictures: Narrowing of the intestines due to scar tissue formation, potentially causing bowel obstruction.
• Short bowel syndrome: Resulting from extensive bowel resection, leading to malabsorption and nutritional deficiencies.
• Death: NEC can be fatal, particularly in severe cases or when treatment is delayed.

Necrotizing enterocolitis (NEC) is a severe and potentially life-threatening condition primarily affecting premature and low birth weight infants. Early diagnosis and prompt treatment are crucial for preventing serious complications and improving outcomes. Understanding the causes, symptoms, diagnostic methods, and treatment options is essential for effective management. If you suspect a case of NEC or have concerns about a premature infant’s gastrointestinal health, seeking immediate medical attention and consulting with a neonatal specialist will help develop a comprehensive treatment plan tailored to the infant’s specific needs and circumstances.