What is the diagnosis and treatment for Necrotizing Enterocolitis (NEC)?

From the Guidelines

Necrotizing enterocolitis (NEC) should be diagnosed and treated promptly with immediate cessation of enteral feeds, gastric decompression, broad-spectrum antibiotics, and supportive care, with surgical intervention as needed, and prevention strategies including probiotics, such as combinations of Lactobacillus spp and Bifidobacterium spp, should be considered in high-risk preterm infants, as supported by moderate- to high-quality evidence 1. The diagnosis of NEC typically involves a combination of clinical and radiographic findings, including abdominal distension, feeding intolerance, bloody stools, and systemic signs like lethargy and temperature instability, as well as abdominal X-rays showing pneumatosis intestinalis or portal venous gas. Management of NEC includes:

• Immediate cessation of enteral feeds
• Gastric decompression via nasogastric tube
• Broad-spectrum antibiotics, such as ampicillin, gentamicin, and metronidazole, for 7-14 days
• Fluid resuscitation and supportive care
• Surgical intervention in cases with intestinal perforation or clinical deterioration despite medical management Prevention strategies for NEC include:
• Preferential use of human milk
• Standardized feeding protocols with slow advancement
• Probiotics in high-risk infants, such as combinations of Lactobacillus spp and Bifidobacterium spp, which have been shown to reduce the risk of NEC and all-cause mortality in preterm infants 1
• Avoiding hyperosmolar formulas and medications Additionally, arginine supplementation may be considered for prevention of NEC in preterm infants, as it has been shown to decrease the incidence of NEC in a randomized controlled trial 2. The pathophysiology of NEC involves intestinal immaturity, abnormal bacterial colonization, and an exaggerated inflammatory response leading to mucosal injury and potential perforation, highlighting the importance of early recognition and prompt treatment to improve outcomes in this condition, which carries significant mortality and long-term morbidity including short bowel syndrome and neurodevelopmental delays.

From the Research

Diagnosis of Necrotizing Enterocolitis (NEC)

• NEC is an inflammatory disease of the gastrointestinal tract characterized by ischemic necrosis of the intestinal mucosa, mostly affecting premature neonates 3.
• The disease occurs when mucosal injury in the preterm intestine results in translocation of luminal bacteria across the epithelial barrier, triggering an exaggerated and damaging local inflammatory response 4.

Treatment of NEC

• Management of NEC includes medical care and surgical approaches, with supportive care and empirical antibiotic therapy recommended to avoid any disease progression 3.
• Medical management of NEC is largely supportive and likely does not modify the etiopathogenesis of this disease 4.
• Antenatal steroids, human milk feedings, adoption of standardized feeding regimens, and probiotics hold promise for prevention of NEC 4.
• The most common approach taken for surgical management is bowel resection with enterostomy formation, but other approaches such as peritoneal lavage, primary anastomosis of bowel, and high diverting jejunostomy or "clip and drop technique" can be used 5.

Antibiotic Regimens for NEC

• No antimicrobial regimen has been shown to be superior to ampicillin and gentamicin in decreasing mortality and preventing clinical deterioration in NEC 3.
• The use of additional antibiotics providing anaerobic coverage, typically metronidazole, or use of other broad-spectrum regimens as first-line empiric therapy is not supported by the very limited current evidence 3.
• There is a high degree of variability in the antibiotic regimen for the treatment of NEC, even within a single NICU, with no regimen appearing superior over another 6.
• An abbreviated course of post-operative antibiotics may be safe 6.

Surgical Indications and Complications

• The only absolute indication for surgery is an intra-abdominal perforation, but there are several relative indications for surgery based on clinical, biochemical, and radiological parameters 5.
• Surgical complications of NEC include stoma-related morbidity, anastomotic leak/stricture, and short-bowel syndrome 5.
• Long-term data on neurodevelopmental outcomes is sparse but the present literature is suggestive of a negative impact in cases of surgically managed NEC 5.