Necrotizing Entercolitis .(NEC)2023.pptx

Necrotizing Entercolitis (NEC)2023.pptx

1. Necrotizing Enterocolitis (NEC) Mekuria Kassa (RN, MSc, Assit , Prof)

2. Definition Necrotizing Enterocolitis (NEC) is an acquired neonatal disorder representing an end expression of serious intestinal injury after the contribution of vascular, mucosal, and metabolic insults to a relatively immature gut.

3. Incidence NEC is predominantly a disorder of preterm infants, with an incidence of 6-10% in infants weighing <1500 gm. The incidence increases with decreasing gestational age. 70-90% of cases occur in high-risk, low birth weight infants, whereas 10-25% occur in full term newborns. Infants with NEC represent 2-5% of neonatal intensive care unit (NICU) admissions.

4. Risk factors • Prematurity . The lower the gestational age the greater the risk of the NEC, because of the immaturity of the circulatory, gastrointestinal, and immune systems. • Asphyxia and acute cardiopulmonary collapse, as they lead to low cardiac output and diminished intestinal perfusion. • Enteral feeding : NEC is rare in unfed infants. About 90-95% of infants with NEC received at least one enteral feeding. o Enteral feeding provides a substrate for proliferation of enteric pathogens. o Hyperosmolar formula may cause direct damage to intestinal mucosa. o Lack of the immuno-protective factors in commercially prepared formula .

5. Risk factor N.B. Breast-feeding significantly lowers the risk of NEC. • Polycythymia • Exchange transfusion. • Large feeding volumes and rapid advancement of enteral feedings. • Enteric pathogenic organisms comprising bacterial and viral pathogens. These include E.coli, Klebsiella, salmonella, rotaviruses, and enteroviruses.

6. Clinical Presentation • Onset time : The onset of NEC varies; in very low birth weight (VLBW) infants, NEC onset follows initiation of enteral feedings and is usually diagnosed between 14-20 days of life. In full-term infants, the age of onset is usually during the first week of life

7. C/P Non-specific signs such as labile temperature, bradycardia, apnea, or other signs of sepsis. • Abdominal distention ( the most frequent early sign noted in 70% of cases) • Ileus(IO). • Gastric and/or bilious aspirate .(2/3 of cases) • Bloody stool. • Peritonitis and signs of intestinal perforation. • Hypotension and shock . • NEC has been classified into stages to include systemic, intestinal, and radiographic findings

8. Laboratory studies • Complete blood count (CBC) with differential WBC count.( may be normal, more frequent either elevated with shift to the left or low) • Blood culture. • Stool screening for occult blood. • Arterial blood gases : metabolic or combined acidosis, or hypoxia may be seen. • Serum electrolytes : hypo or hyper natermia and hyper kalemia are common.

9. Radiological studies • Abdominal X-ray in flat , lateral decubitus, and erect positions.

10. Management Basic management of NEC • Nothing by mouth/NPO to allow gastrointestinal rest. • Insert gastric tube to keep the bowel decompressed. • Remove the umbilical catheter if present. • Antibiotics : Start ampicillin and gentamicin or cefotaxime IV. Add anaerobic coverage (clindamycin or metronidazole). • Monitor for gastrointestinal bleeding .( check all gastric aspirates and stool for blood )

11. mgt • Monitor closely vital signs , abdominal circumference, and laboratory and radiological studies. • Strict monitoring of fluid intake and output ,try to maintain urine output of 1-3 ml/kg/hr. • Septic workup .

12. Management of each specific stage Stage Systemic sign Intestinal sign Radiological sign Treatment IA Suspected NEC Temperature instability, apnea, bradycarida , and lethargy Residuals, mild abdominal distension, and heme-positive stool Normal or intestinal dilation NPO and antibiotics for 3 days pending cultures IB Suspected NEC Same as above Bright blood from rectum Same as above Same as above IIA Definite NEC Mildy ill Same as above Same as above, plus diminished bowel sounds, and with or without abdominal tenderness Intestinal dilatation, ileus, and pneumatosis intestinalis NPO and antibiotics for 7-10 days of examinations IIB Definite NEC Moderately ill Same as above, plus mild metabolic acidosis Same as above, plus definite abdominal tenderness, and with or without abdominal cellulitis or lower quadrant mass Same as above, with or without portal vein gas, and with or without ascites NPO, antibiotics for 14 days, and correction for acidosis IIIA Advanced NEC Severely ill, bowel intact Same as above, plus hypotension, severe apnea, combined respiratory and metabolic acidosis, DIC, neutropenia, and anuria Same as above, plus signs of generalized peritonitis, marked tenderness, distention of abdomen, and abdominal wall erythema Same as above Same as above, plus adequate fluid, FFP, inotropic drips, and intubation. Surgical intervention if fails to improve within 48 hours IIIB Advanced NEC very ill with bowel perforation Same as above Same as above Same as above, plus pneumoperitoneum Same as above, plus surgical intervention