May 17 is NEC Awareness Day!

I will never forget one of my long-term primary patients from years ago—a preterm, growth-restricted baby boy. He was progressing steadily in the NICU until, seemingly overnight, everything changed. He was diagnosed with Stage III necrotizing enterocolitis (NEC) and underwent bowel resection, leading to short bowel syndrome (SBS). He needed a Broviac central line and was dependent on cyclic parenteral nutrition (PN) for growth.

Despite these challenges, he remained the sweetest soul, and his parents were resilient and devoted. They sent me Christmas cards for years after his discharge. Against the odds, he continued to grow and thrive, embodying both the devastation and hope wrapped in an NEC diagnosis.

This experience taught me that behind every NEC statistic is a child and family whose lives are forever altered. The month of May is NEC Awareness Month, and I'm reminded of why our vigilance and advocacy around this disease are so crucial.

⚠️ Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease that primarily affects our most vulnerable patients. The disease involves acute inflammation, bacterial invasion, and necrosis of the intestinal wall.

While most commonly seen in premature infants, particularly those born at less than 32 weeks gestation or with birth weights under 1500 grams, NEC also occurs in term neonates with predisposing conditions such as congenital heart disease or perinatal asphyxia.

NEC is not a singular disease but rather a spectrum of acquired intestinal injuries. This spectrum includes:

• Classic NEC: The most common form, typically seen in preterm infants after the initiation of enteral feeds

• Cardiac-induced NEC: Related to mesenteric hypoperfusion in infants with congenital heart disease

• Atypical or transfusion-associated NEC: Often occurring within 48-72 hours of packed red blood cell transfusion

• Term infant NEC: Usually associated with specific risk factors such as hypoxic-ischemic injury or polycythemia

Understanding these subtypes is essential for tailoring prevention strategies and treatment approaches to individual patients.

🌪️The Perfect Storm: Pathophysiology of NEC

NEC's pathophysiology is multifactorial, representing a "perfect storm" of conditions that converge in the vulnerable preterm gut. The key contributing factors include:

1. Prematurity and Intestinal Immaturity

The preterm infant's intestinal tract is characterized by:

• Reduced barrier function with increased permeability

• Immature tight junctions between enterocytes

• Underdeveloped mucosal protective mechanisms

• Insufficient production of protective antimicrobial peptides

• Immature peristaltic patterns that prolong bacterial exposure

These factors create an environment where the intestinal barrier is easily breached, allowing bacterial translocation and triggering the inflammatory cascade.

2. Microbial Dysbiosis

The preterm infant's gut microbiome differs significantly from that of term infants:

• Delayed colonization with beneficial bacteria

• Dominance of potentially pathogenic species

• Reduced microbial diversity

• Higher concentrations of Proteobacteria (including Enterobacteriaceae)

• Lower concentrations of Bifidobacteria and Lactobacilli

This dysbiosis is exacerbated by common NICU interventions such as antibiotic exposure, delayed feeding, and limited exposure to maternal microbiota.

3. Enteral Feeding Considerations

Feeding practices significantly impact NEC risk:

• Breast milk reduces the risk of NEC risk 6-10 fold compared to formula feeding

• Rapid advancement of feeds may overwhelm the immature gut

• Hyperosmolar formulas and medications may damage intestinal mucosa

Human milk is protective through multiple mechanisms:

• Immunoglobulins (particularly secretory IgA)

• Lactoferrin with antimicrobial properties

• Human milk oligosaccharides (HMOs) that promote beneficial bacteria

• Growth factors that enhance intestinal maturation

• Anti-inflammatory cytokines that modulate immune response

4. Immune Dysregulation

The preterm infant's immune system is characterized by:

• Exaggerated pro-inflammatory responses

• Ineffective regulation of inflammatory cascades

• Overproduction of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8)

• Increased toll-like receptor 4 (TLR4) expression, which recognizes bacterial lipopolysaccharide

• Reduced production of anti-inflammatory mediators

This immune dysregulation creates a hyperinflammatory environment that contributes to tissue damage.

5. Impaired Intestinal Perfusion

Circulatory factors that contribute to NEC include:

• Hypoxic-ischemic events that compromise intestinal blood flow

• Hypotension requiring vasopressor support

• Ductal steal phenomenon in infants with patent ductus arteriosus

• Reduced microvascular density in the preterm intestine

• Impaired autoregulation of mesenteric blood flow

Together, these factors result in a cycle of intestinal injury, inflammation, and progressive tissue damage that characterizes NEC.

(Hackham & Sodhi, 2018)

🚨The Clinical Presentation: Recognizing NEC Early

Early recognition of NEC is critical for timely intervention. The clinical presentation typically includes a constellation of gastrointestinal and systemic signs.

Gastrointestinal Signs

• Abdominal distention: Often one of the earliest signs, with progressive worsening

• Bloody stools: Ranging from occult blood to grossly bloody diarrhea

• Abdominal wall discoloration: Erythema or a bluish discoloration suggesting possible perforation

• Palpable bowel loops: Indicating dilated, thickened intestinal segments

• Decreased or absent bowel sounds: Suggesting ileus

Systemic Signs

• Lethargy, apnea, bradycardia: Reflecting systemic involvement

• Temperature instability: Often manifesting as hypothermia

• Hypotension and poor perfusion: Indicating septic shock in advanced cases

• Metabolic acidosis: Resulting from poor perfusion and anaerobic metabolism

• Thrombocytopenia: A common hematologic finding that may precede other signs

• Neutropenia or leukocytosis: Reflecting the inflammatory response

Radiologic Findings

Abdominal radiographs remain the cornerstone of NEC diagnosis:

• Pneumatosis intestinalis: The radiographic hallmark of NEC, representing gas within the intestinal wall

• Portal venous gas: Indicating more severe disease with bacterial translocation

• Fixed, dilated intestinal loops: Suggesting areas of affected bowel

• Pneumoperitoneum: Representing intestinal perforation, a surgical emergency

Early stages of NEC may show only nonspecific findings such as dilated bowel loops or a gasless abdomen, highlighting the importance of serial examinations and radiographs in suspected cases.

📊Staging Systems: Guiding Management Decisions

The modified Bell's staging criteria remain widely used to classify NEC severity and guide management:

Stage I: Suspected NEC

• Mild systemic illness

• Nonspecific gastrointestinal signs

• Normal or nonspecific radiographic findings

• Managed with antibiotics and bowel rest

Stage II: Definite NEC

• Moderate systemic illness

• Definite gastrointestinal signs

• Pneumatosis intestinalis or portal venous gas on imaging

• Managed with antibiotics, bowel rest, and supportive care

Stage III: Advanced NEC

• Severe systemic illness with cardiovascular and respiratory compromise

• Marked gastrointestinal signs with peritonitis

• Pneumoperitoneum or other signs of perforation

• Requires surgical intervention

Other classification systems incorporate laboratory values, such as thrombocytopenia and neutropenia, which are associated with poorer outcomes and may help identify infants requiring more aggressive intervention.

(Soni et al, 2020)

Arrow 1 shows the branching tree of the portal venous gas. Arrow 2 shows the crescents of pneumatosis. Arrow 3 shows widespread soap bubbling

🍼Prevention: The Best Treatment

Prevention remains the cornerstone of NEC management. Evidence-based strategies include:

Human Milk as Medicine

• Mother's own milk (MOM) is optimal, with a dose-dependent reduction in NEC risk

• Donor human milk (DHM) is preferable to formula when MOM is unavailable

• Human milk-derived fortifiers may offer advantages over bovine-derived products

• Human milk oligosaccharides (HMOs) promote a healthy microbiome and enhance gut maturation

• Colostrum oral care (aka Oral Immune Therapy) provides local immune benefits even before enteral feeding is initiated

Standardized Feeding Protocols

• Evidence-based advancement guidelines reduce practice variation

• Slow advancement rates (15-20 mL/kg/day) may be safer for extremely preterm infants

• Trophic feeding protocols that maintain gut stimulation shortly after birth

• Careful monitoring parameters for signs of feeding intolerance

• Standardized responses to feeding intolerance that avoid unnecessary withholding of feeds

Microbiome Protection Strategies

• Avoiding unnecessary antibiotics preserves microbial diversity

• Limiting duration of empiric antibiotics when cultures remain negative

• Early skin-to-skin care promotes healthy microbial colonization

• Avoiding H2 blockers and proton pump inhibitors that alter gut pH and microbial composition

• Human milk feeding practices that support a healthy microbiome

Antibiotic Stewardship

• Discontinuing antibiotics at 36-48-hours when cultures are negative

• Narrowing antibiotic coverage based on culture results

• Avoiding broad-spectrum antibiotics when narrower options are appropriate

• Regular antibiotic timeout discussions among the healthcare team

• Tracking antibiotic usage rates to identify opportunities for improvement

Probiotic Supplementation

• Meta-analyses support probiotic efficacy in reducing NEC incidence

• Multi-strain preparations may be more effective than single strains

• Bifidobacterium and Lactobacillus species are most commonly studied

• Safety considerations include risk of translocation sepsis in extremely preterm infants

• There is currently no probiotic approved by the FDA to prevent NEC in preterm infants in the United States

Other Promising Approaches

• Lactoferrin supplementation shows potential for NEC prevention

• Pentoxifylline may modulate inflammatory responses

• Stem cell therapies are being investigated for intestinal repair

• Amniotic fluid components may promote intestinal development

• Toll-like receptor modulators could prevent excessive inflammation

👩🏻‍⚕️When Prevention Fails: Treatment Approaches

Despite prevention efforts, NEC still occurs. Treatment approaches include:

Medical Management

• Bowel rest: Withholding enteral feeds while maintaining nutrition via parenteral routes

• Broad-spectrum antibiotics: Typically covering gram-negative, gram-positive, and anaerobic organisms

• Gastric decompression: Reducing intestinal distention and bacterial proliferation

• Fluid resuscitation and cardiovascular support: Maintaining adequate tissue perfusion

• Correction of coagulopathy and thrombocytopenia: Reducing bleeding risk

• Serial abdominal examinations and radiographs: Monitoring disease progression

Surgical Intervention

Approximately 30-50% of infants with NEC require surgical management. Indications include:

• Pneumoperitoneum: Indicating intestinal perforation

• Clinical deterioration despite maximal medical therapy

• Abdominal wall erythema or discoloration

Surgical approaches include:

• Primary peritoneal drainage: Often used as a temporizing measure in extremely preterm infants

• Laparotomy with resection: Removing necrotic bowel segments

• Creation of ostomies: Diverting intestinal contents

Long-term Outcomes and Complications

NEC survivors face significant short and long-term challenges:

Gastrointestinal Complications

• Short bowel syndrome (SBS): Resulting from extensive intestinal resection

• Intestinal strictures: Occurring in up to 35% of medically managed cases

• Malabsorption and failure to thrive: Due to reduced absorptive surface area

• Recurrent feeding intolerance: Requiring modified feeding approaches

• Cholestatic liver disease: Associated with prolonged parenteral nutrition

Neurodevelopmental Outcomes

NEC survivors, particularly those requiring surgery, have higher rates of:

• Cerebral palsy

• Cognitive impairment

• Hearing and visual impairments

• Language delays

• Behavioral challenges

These neurodevelopmental impacts may be related to inflammatory mediators affecting the developing brain, prolonged hospitalization, nutritional deficits, and associated comorbidities.

Family Impact

The impact of NEC extends beyond the infant to affect the entire family:

• Prolonged hospitalization disrupting parent-infant bonding

• Financial strain from medical expenses and lost work time

• Emotional trauma associated with critical illness

• Medically complex children with long-term complications

• Increased parental stress and anxiety

Supporting NEC Survivors: The Long Road Ahead

Care for NEC survivors requires a multidisciplinary approach:

Nutritional Support

• Specialized feeding approaches for children with short bowel syndrome

• Monitoring for micronutrient deficiencies

• Growth tracking with adjusted expectations

• Transitioning from parenteral to enteral nutrition

• Managing oral aversion and feeding difficulties

Developmental Follow-up

• Early intervention services

• Regular developmental assessments

• Specialized therapies (physical, occupational, speech)

• Educational support and advocacy

• Family support resources

Building Resilience

Despite the challenges, many NEC survivors demonstrate remarkable resilience. Supporting this resilience involves:

• Celebrating small victories

• Building support networks

• Connecting with other NEC families

• Focusing on capabilities rather than limitations

• Advocating for needed services and resources

NEC Awareness and Advocacy: Making a Difference

May 17th is designated as NEC Awareness Day, providing an opportunity to:

• Educate healthcare providers about prevention strategies

• Raise public awareness about this devastating disease

• Support research initiatives seeking better prevention and treatment

• Connect families affected by NEC with resources and support

• Advocate for policies that support human milk feeding and optimal NICU care

Organizations like the NEC Society bring together researchers, clinicians, and families to advance prevention, treatment, and support for those affected by NEC.

NEC remains one of the most challenging diseases in neonatal care, but there is reason for hope. Advances in understanding the pathophysiology, improving prevention strategies, and developing targeted therapies offer promise for reducing the burden of this disease.

As NICU nurses, our vigilance in identifying early signs, our advocacy for evidence-based prevention practices, and our compassionate care for affected infants and families make a profound difference. Every baby spared from NEC represents a family saved from trauma and a life preserved from potential long-term complications.

During NEC Awareness Month, let us commit to continued progress toward a future where NEC no longer devastates our most fragile patients.

Resources for Families and Professionals

• NEC Society

• Short Bowel Syndrome Foundation

• Human Milk Banking Association of North America

Let's work together to create a world without NEC.

Wishing you the best

Amanda

References

Keefe G, Jaksic T, Neu J. Necrotizing Enterocolitis and Short Bowel Syndrome. In: Martin RJ, et al. Fanaroff and Martin's Neonatal-Perinatal Medicine. 11th ed. 2020

de la Cruz D, Gipson DR. Moving Beyond NEC. In: Martin RJ, et al. Fanaroff and Martin's. 11th ed. 2020

Ortigoza EB. Feeding Intolerance. In: Kliegman R, et al. Nelson Textbook of Pediatrics, 21st ed. 2020

National Association of Neonatal Nurses. Neonatal Parenteral and Enteral Nutrition: A Resource Guide for the Student and Novice Neonatal Nurse Practitioner. 2020

Neu J, Walker WA. Necrotizing enterocolitis. N Engl J Med. 2011;364(3):255–264. doi:10.1056/NEJMra1005408

Sharif S, et al. Probiotics to prevent NEC in very preterm or very low birth weight infants. Cochrane Database Syst Rev. 2020;10:CD005496. doi:10.1002/14651858.CD005496.pub5

Gephart SM, McGrath JM. NEC Zero: A prevention-focused approach. Adv Neonatal Care. 2012;12(1):23–32. doi:10.1097/ANC.0b013e3182425df0

Hackam DJ, Sodhi CP. Toll-like receptor-mediated intestinal inflammatory imbalance in the pathogenesis of necrotizing enterocolitis. Cell Mol Gastroenterol Hepatol. 2018;6(2):229-238.e1. doi:10.1016/j.jcmgh.2018.04.001

Hair AB, et al. Beyond necrotizing enterocolitis prevention: Improving outcomes with an exclusive human milk-based diet. Breastfeed Med. 2016;11(2):70-74. doi:10.1089/bfm.2015.0134

Patel RM, Denning PW. Intestinal microbiome and its relationship with necrotizing enterocolitis. Pediatr Res. 2015;78(3):232-238. doi:10.1038/pr.2015.97

How to use abdominal X-rays in preterm infants suspected of developing necrotising enterocolitis. Archives of Disease in Childhood - Education and Practice 2020;105:50-57.

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