PEDS Flashcards
Necrotizing Enterocolitis
Acquired neonatal disorder that causes serious intestinal injury Combination of vascular, mucosal, and metabolic insults Unknown cause
What is the most common GI emergency in preterm infants?
Necrotizing enterocolitis
Sequence of necrotizing enterocolitis
Initial ischemic / toxic mucosal damage Loss of mucosal integrity Availability of suitable substrate (enteral feedings) Bacterial proliferation Invasion of damaged mucosa by gas-producing organisms Intramural bowel gas Transmural necrosis or gangrene Intestinal perforation Peritonitis
Most commonly involved areas of necrotizing enterocolitis
Terminal ileum Proximal colon
Appearance of necrotizing enterocolitis (gross and microscopic)
Gross: irregularly dilated with hemorrhagic or ischemic areas of frank necrosis Microscopic: mucosal edema, hemorrhage, ulceration
Risk factors for necrotizing enterocolitis
Prematurity is the primary risk factor -Immature GI system -Immature immune response -Impaired circulatory dynamics
How is breast milk protective against NEC?
IgA Macrophages, lymphocytes Complement components Lysozyme, lactoferrin Acetylhydrolase
GI and systemic signs of NEC
GI: feeding intolerance, abdominal distension, abdominal tenderness, emesis, occult/gross blood in stool, abdominal mass, erythema of abdominal wall Systemic: lethargy, apnea/respiratory distress, temperature instability, hypotension, acidosis, glucose instability, DIC, positive blood cultures
Timeline for NEC presentation
The closer to full term the child is, the more acute the onset will be (full term = 3 days;
Sudden onset NEC
Full term or preterm infants Acute catastrophic deterioration Respiratory decompensation Shock/acidosis Marked abdominal distension Positive blood culture
Insidious onset NEC
Usually preterm Evolves during 1-2 days Feeding intolerance Change in stool pattern Intermittent abdominal distension Occult blood in stools
Dx of NEC
Abdominal x-rays Supportive of NEC: abnormal gas patterns, ileus, fixed sentinel loop of bowel, areas suspicious for pneumatosis intestinalis Confirmatory of NEC: intramural bowel gas (pneumatosis intestinalis), intrahepatic portal venous gas
Pneumatosis Intestinalis
Hydrogen gas within the bowel wall -Linear streaking pattern (“hallmark” of NEC) -Bubbly pattern
Portal venous gas
Extension of pneumatic intestinalis into portal venous circulation -Linear branching lucencies overlying the liver and extending to the periphery -Associated with severe disease and high mortality
Pneumoperitoneum
Free air in the peritoneal cavity secondary to perforation -Falciform ligament may be outlined (“football” sign) SURGICAL EMERGENCY
Stage I: suspected NEC
Systemic: nonspecific– apnea, bradycardia, lethargy, temp instability Intestinal: feeding intolerance, gastric residual, guiac + stool Radiologic: normal or nonspecific
Stage II-A: Mid NEC
Systemic: similar to stage I Intestinal: abdominal distension, no BS, +/- tenderness, gross blood in stool Radiographic: ileus w/ dilated loops w/ focal pneumatosis intestinalis
Stage II-B: Moderate NEC
Systemic: Stage I plus mild acidosis and thrombocytopenia Intestinal: Increased distension, abdominal wall edema, tenderness, +/- palpable mass Radiographic: extensive pneumatosis and early ascites, +/- portal venous gas
Stage III-A: Advanced NEC
Systemic: resp/metabolic acidosis, assisted vent– apnea, decreased BP and urine output, neutropenia, coagulopathy Intestinal: increased edema, erythema, or discoloration, induration of abdominal wall Radiographic: prominent ascites, paucity of bowel gas, persistent sentinel loop
Stage III-B: Advanced NEC
Systemic: Generalized edema, decreased vital signs/lab values, shock, DIC Intestinal: tense, discolored abdomen with ascites Radiographic: absent bowel gas, intraperitoneal free air
BASIC NEC Protocol
NPO; TPN NG tube for decompression Close monitoring of VS and head circumference Abx– ampicillin/gentamicin Monitor for GI bleed Monitor I&O Remove K from IV fluids if hyperkalemic or anuric Labs: CBC, CMP, ABGs (every 6-8 hours) -Check for sepsis X-rays (every 6-8 hours)
When to get surgical consult
Suspected or proven NEC
Indications for surgery in NEC
Portal venous gas; pneumoperitoneum Clinical deterioration Positive paracentesis Fixed intestinal loop on serial x-rays (over 24 hours) Erythema of abdominal wall (peritonitis)
NEC complications
Feeding difficulties FTT Malabsorption Strictures (most common) Fistulas Hepatic dysfunction secondary to long term TPN Long term sequelae from neuro or renal damage IF bowel resected: short gut syndrome, nutritional deficiencies, obstruction (Adhesions), long term morbidity with ostomies
