NECROTIZING ENTEROCOLITIS (NEC)Rhonda J. Petty, BSN, RN

East Carolina University College of Nursing, Greenville, North Carolina

Pathophysiology/Risk Factors•*Prematurity: the most consistently identified risk factor!

•Intestinal Ischemia & Inflammation: hypoxia, hypoperfusion, enteral feedings and abnormal colonization of the gut lead to epithelial cell injury and inflammation. Premature infants have an increased inflammatory response which further injures the compromised gut. Secretory IgA, a protective agent against bacteria, is deficient in the premature gut.

•Enteral Feedings: Gastrointestinal immaturity causes decreased motility leading to stasis of enteral feedings and fermentation, overgrowth of bacteria, and gaseous distension which causes pneumatosis, increased intraluminal pressure and decreased blood flow.

•Other Risk Factors associated with NEC: Birth weight <1,500 gm, intrauterine growth restriction, pregnancy-induced hypertension, feedings of infant formula, maternal chorioamnionitis, maternal smoking, systemic antibiotic therapy, hemodynamically significant patent ductus arteriosis, umbilical catheters and- although a causal relationship is not yet known- blood transfusions.

Preventive Strategies•Early/Preferred feedings of breast milk: Breast fed infants are 6-10 times less likely to develop NEC than formula fed infants. Epidermal growth factor, which limits ileal damage from bile acids is found in breast milk and is not present in infant formula.

•Standardized feeding guidelines: written guidelines replace daily feeding orders and contain standard thresholds on how to manage signs of feeding intolerance and criteria for discontinuing feedings. Implementing such guidelines reduces the risk for NEC by up to 87% for infants <2500gms.

•Probiotics: increase gut motility, control inflammatory cytokines and limit the growth of bacteria. Probiotics effectively reduce the incidence and mortality of NEC, however, more studies are necessary to determine a safe and effective approach.

•Ibuprofen vs Indomethacin to treat PDA: a meta-analysis of 15 studies showed the risk of NEC decreases with the use of ibuprofen over indomethacin.

•Maintain awareness of potential risk factors!Nursing Implications• Promote the use of mother’s breast

milk! Nurses play a pivotal role in encouraging mothers to provide breast milk for their infants and providing teaching on bringing in and maintaining their milk supply.

• Implement standardized feeding guidelines and a well-defined approach to feeding intolerance : standardized guidelines promote awareness of the risk factors and early signs of NEC.

• Notify physician or NNP of any systemic or GI signs of NEC such as: apnea, bradycardia, hypothermia, lethargy, poor feeding, vomiting, increasing gastric residuals, bloody or bilious residuals, mild abdominal distension, bloody stools.

• Know the risk factors and always maintain a high index of suspicion for NEC!

Clinical Signs/Bell’s Staging

References

Review of Bell's stages

Clinical findings Radiographic findings Gastrointestinal findings

Stage I

Apnea and bradycardia, temperature instability

Normal gas pattern or mild ileus

Gastric residuals, occult blood in stool, mild abdominal distention

Stage II A

Apnea and bradycardia, temperature instability

Ileus gas pattern with one or more dilated loops and focal pneumatosis

Grossly bloody stools, prominent abdominal distention, absent bowel sounds

Stage II BThrombocytopenia and mild metabolic acidosis

Widespread pneumatosis, ascites, portal-venous gas

Abdominal wall edema with palpable loops and tenderness

Stage III A

Mixed acidosis, oliguria, hypotension, coagulopathy

Prominent bowel loops, worsening ascites, no free air

Worsening wall edema, erythema and induration

Stage III B

Shock, deterioration in laboratory values and vital signs

Pneumoperitoneum

Perforated bowel

(Gordon, et al, 2007).Clark, 2007)

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