Necrotizing Enterocolitis“From ghoulies to ghosties andlong leggety beasties & thingsthat go bump in the night, goodlord deliver us”Bugs, Drugs and Things that goBump in the NightOld Cornish Prayer“Caring for premature infant withNEC is like riding a mile-high rollercoaster without brakes. All you cando is hang on for the ride and watchout for the bumps.” Epidemiology Pathophysiology Diagnosis Management Prevention RA Polin 2005The Case BeginsBaby “M” was a 1150 male infant (27 wkgestation), born to a 26 year old woman.Mrs. “M” admitted to recreational use ofcocaine. Three days prior to delivery shewas given indomethacin because of pretermlabor.The case continued The baby was delivered by emergencycesarean section because of late decelerations.Apgar scores were 1 & 3 & baby “M” requiredendotracheal intubation.
The case continuedThe case continuedBecause of worsening respiratory distress, anumbilical arterial line was placed at L4. A CBCobtained from the UA was remarkable for a Hct 71%. On day one of life, the infant was placedon TPN. The case continuedThe case continuedWithin 72 hours, feedings were begun. Thebaby was advanced to full feedings over 3 days.On day 4 of life, a murmur was heard and anechocardiogram and chest x-ray were obtained.Total fluid intake at that time was 185 ml/kg day. The case continuedThe case continuedOn day 10 of life, he needed NaHCO3because of a mild metabolic acidosis. Gastricaspirates increased in volume and were bloodtinged. A CBC was remarkable for leukopeniaand thrombocytopenia. On day 11, he becamedistended & developed erythema of theabdominal wall.
Epidemiology of NEC Affects 6-8% of VLBW infants Widely varying incidence between centersIncidence inversely related to degree ofprematurity No seasonal or sex predilection (? racial effect)Age at diagnosis is inversely related togestational age and degree of prematurity Gestational age*Age at onset 30 weeks20.2 days31-33 weeks13.8 days 34 weeks5.4 daysFull term1-3 daysVulnerable intestine Bacterial ColonizationIntestinal ischemia“Diving seal reflex”Formula feeding*Stoll et al J Ped. 96: 447, 1980Martin CouneyPathophysiology of NECBreast feedingHypertonic tesImmunoglobulinGrowth factorsPAF acetylhydrolaseFormula feedingBacterial ColonizationBacterial Replication( substrate)H2 gas ProductionPneumatosisMucosal invasion(endotoxin)Cytokine productionPAFTNF/cytokinecascadeSepsis/shock/SIRS
Diagnosis of NECHigh index of suspicion based on history andphysical findings Early appearances are subtle and easily confusedwith neonatal sepsis. Diagnosis and Staging of NECEarly gastrointestinal findings may be non-specificPoor motilityBlood in stool Vomiting Diarrhea – Apnea (pause in breathing)– Bradycardia (slowing of heart rate)– lethargy– temperature instabilityDiagnosis and Staging of NECGuardingDistension Feeding intolerance Classification of NECLater signs reflect progression of illness.Abdominal tendernessAbdominal wall erythema Peritonitis AscitesPalpable massHypotension Bleeding disorders Acidosis Stage 1: suspect NEC - signs of sepsis, feedingintolerance bright red blood per rectumStage 2: Proven NEC- all of the above, pneumatosis, portal vein gas metabolic acidosis ascitesStage 3: Advanced NEC- all of the above, clinicalinstability, definite ascites pneumoperitoneumHow Do You Make the Diagnosis?Think of the diagnosis!Serial physical examination Laboratory testing Abdominal x-rays NecrotizingEnterocolitisPneumatosis intestinalis
NecrotizingEnterocolitisPortal vein gasNecrotizing EnterocolitisStatic loopsNecrotizing eum“football” signPneumoperitoneumWhat is the Medical Treatment? Necrotizing EnterocolitisPneumoperitoneum/scrotumStop the feedingsParenteral antibioticsNasogastric decompressionParenteral nutritionFluid resuscitation
Firm Indications for SurgicalInterventionPerforated viscus Abdominal mass Fixed, dilated loop Positive paracentesis Necrotizing EnterocolitisIntestinal gangrene and perforationWhat is the outcome? Infants treated medically survival is 95% Infants requiring surgery survival is 70-75%What is the outcome?Surgical NEC (but not medical NEC) was an independent riskfactor for the combined outcome of neuro-developmentalimpairment (blindness, deafness, PDI/MDI 70 or CP)!Hintz SR & the NICHD network Pediatrics 115: 696, 2005ConclusionHow Can NEC be Prevented?Prematurity is the single greatest risk factorfor NEC & avoidance of premature birth is thebest way to prevent NEC Breast feeding Antenatal steroids Cautious advancement of feedings (perhaps) Cohorting during epidemics ProbioticsThe role of feeding in the pathogenesis ofNEC is uncertain, but it seems prudent to usebreast milk (when available) and advancefeedings slowly and cautiously
RA Polin 2005 “Caring for premature infant with NEC is like riding a mile-high roller coaster without brakes. All you can do is hang on for the ride and watch out for the bumps.” Epidemiology Pathophysiology Diagnosis Management Prevention The Case Begins Baby