Infantools | Nutrition FeaturedImagejpg

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) belongs to acute abdomen events (inflammatory subgroup). It is typical disease of extreme prematurity – incidence is inversely proportional to advancing gestational age (1-5% of newborns admitted to the neonatal intensive care unit). Mortality associated with NEC varies between 20-50%.

Multifactorial basis of NEC makes it difficult to pinpoint single aspect that is responsible for the development of enterocolitis.

Prematurity involves intestinal functionality (digestion, motility, splanchnic circulation regulation, immunity, barrier mechanism) and anatomy. Pathogenic bacterial flora can directly damage the preterm intestinal mucosa (mucositis), initiating inflammatory response with the production of reactive oxygen species, vasoactive agent (hypoperfusion causing ileus) and cytokines. These mechanisms further damage the mucosa and submucosa, bacteria can subsequently translocate to the bloodstream with the end result of septic shock.

Complications of NEC include perforation (pneumoperitoneum) and peritonitis. Depending on the severity of the disease and affected intestinal length, varying portion of intestine (typically small intestine – terminal ileum) may be resected, leading short bowel syndrome.

Differential diagnosis include the following conditions:

  • FIP = feeding intolerance of prematurity
  • VEI = viral enteritis of infancy (can affect also older children)
  • SIP = spontaneous intestinal perforation

Diagnosis

Clinical signs

  • ileus symptomatology (vomiting, bilious aspirates, distended, tender abdomen, risk of perforation and peritonitis)
  • enterorrhagia
  • discoloration of abdomen
  • painfulness
  • septic shock (circulation and ventilation instability, thermal fluctuations, apathy)

Laboratory findings

  • Increased inflammatory markers (C-reactive protein, procalcitonin, interleukin-6)
  • full blood count with leucopenia/leucocytosis, shift to the left
  • blood gas with metabolic lactic acidosis

Imaging

  • X-ray showing dilated intestinal loops with air-fluid levels (ileus)
  • pneumatosis intestinalis (free air within the bowel wall)
  • perforation – pneumoperitoneum (free air) – anterior-posterior projection with “football sign”, sideways projection with accumulation of free air around the liver
  • ultrasound (ileus, free air in vena portae – visible also on native X-ray)

Clinical and radiography features form Bell’s criteria for NEC staging (modified by Walsh and Kliegman) – stage I (suspected NEC), stage II (confirmed NEC), stage III (advanced NEC).

Therapy

Conservative management

  • septic shock treatment (mechanical ventilation, massive volume therapy)
  • total parenteral nutrition
  • antibiotics
  • blood transfusion (erythrocytes, thrombocytes)
  • analgesia

Surgery

  • 30-50% of cases (pneumoperitoneum = surgical emergency)
  • resection of necrotic segments (usually terminal ileum)
  • stoma
  • surgical complication: hypothermia, hypotension/hypovolemia, hemorrhage (liver)
  • consequences of NEC: stenosis (requires additional surgery), short bowel syndrome

Prevention

  • colostrum and maternal milk
  • probiotics (lactobacillus spp., Bifidobacterium spp.) initiated during the first week of life based on the newborn’s status
  • antenatal corticosteroids decrease the incidence of NEC
  • careful fluid restrictions
  • standardized feeding protocol with step-wise enteral feeds advancements based on the risk factors

References

① Rose AT, Patel RM. A critical analysis of risk factors for necrotizing enterocolitis. Semin Fetal Neonatal Med. 2018;23(6):374-379. doi:10.1016/j.siny.2018.07.005

② Kim JH. Role of Abdominal US in Diagnosis of NEC. Clin Perinatol. 2019;46(1):119-127. doi:10.1016/j.clp.2018.10.006

Similar Posts

  • Resuscitation

    Perinatal asphyxia remains one of the most common indications for postnatal resuscitation. The necessary prerequisites for successful resuscitation are properly equipped rooms (delivery suite, neonatal wards with the right and functional equipment; warmed up to the temperature of 26 °C) with properly trained personnel. Ventilation (and circulation dysfunction) are indications to initiate resuscitation…

  • Apnea

    Apneas represent another important group of respiratory/ventilation dysfunctions in newborns (apart from perinatal asphyxia and respiratory distress syndrome). They are generally defined as a cessation of breathing movements and air flow for more than 20 seconds, thus often being accompanied by desaturation and bradycardia. Spontaneous breathing causes water in lungs to be resorbed into blood and…

  • Persistent ductus arteriosus

    Persistent ductus arteriosus (PDA) connects aorta with main pulmonary artery (MPA) (or left pulmonary artery – LPA) and during fetal life serves as important right-left shunt => mixed blood flowing from the pulmonary artery to the descendant aorta and supplying the lower half of the body. PDA prenatally remains open due to low partial pressure…

  • Retinopathy of prematurity

    Retinopathy of prematurity (ROP) is a vasoproliferative disorder (fibrovascular proliferation) of developing retina in preterm infants. It is characterised by disorganized growth of abnormal new blood vessels (=> hemorrhage) and fibrous tissue ( => contracted scar tissue causing retinal detachment). Incidence of ROP is inversely proportional to the gestational age (general ROP screening…

  • Acute abdomen

    Acute abdomen events arise from a number of diseases based on the predominant pathophysiology. They require urgent revision. Basic division of acute abdomen in newborns: congenital gastrointestinal malformations non-inflammatory→ ileus of prematurity (IOP)→ spontaneous intestinal perforation (SIP)→ incarceration of inguinal hernia→ testicular torsion (unilateral orchidectomy) inflammatory→ necrotizing enterocolitis (NEC)→ peritonitis (usually…

  • Congenital anomalies of gastrointestinal tract

    Congenital anomalies of gastrointestinal tract (GIT) can be sometimes detected by the prenatal screening (ultrasound – polyhydramnios, direct visualisation of affected GIT; biochemistry – elevated alpha-fetoprotein in gastroschisis and omphalocele). Postnatal investigations include proper clinical examination (distended abdomen, vomiting with/without bilious aspirates) and imaging techniques (ultrasound, native or contrast radiography). The lower (distal) the obstruction in the…

Leave a Reply

Your email address will not be published. Required fields are marked *

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.