PEDS

Question 1

Necrotizing Enterocolitis

Answer 1

Acquired neonatal disorder that causes serious intestinal injury Combination of vascular, mucosal, and metabolic insults Unknown cause

Question 2

What is the most common GI emergency in preterm infants?

Answer 2

Necrotizing enterocolitis

Question 3

Sequence of necrotizing enterocolitis

Answer 3

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

Question 4

Most commonly involved areas of necrotizing enterocolitis

Answer 4

Terminal ileum Proximal colon

Question 5

Appearance of necrotizing enterocolitis (gross and microscopic)

Answer 5

Gross: irregularly dilated with hemorrhagic or ischemic areas of frank necrosis Microscopic: mucosal edema, hemorrhage, ulceration

Question 6

Risk factors for necrotizing enterocolitis

Answer 6

Prematurity is the primary risk factor -Immature GI system -Immature immune response -Impaired circulatory dynamics

Question 7

How is breast milk protective against NEC?

Answer 7

IgA Macrophages, lymphocytes Complement components Lysozyme, lactoferrin Acetylhydrolase

Question 8

GI and systemic signs of NEC

Answer 8

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

Question 9

Timeline for NEC presentation

Answer 9

The closer to full term the child is, the more acute the onset will be (full term = 3 days;

Question 10

Sudden onset NEC

Answer 10

Full term or preterm infants Acute catastrophic deterioration Respiratory decompensation Shock/acidosis Marked abdominal distension Positive blood culture

Question 11

Insidious onset NEC

Answer 11

Usually preterm Evolves during 1-2 days Feeding intolerance Change in stool pattern Intermittent abdominal distension Occult blood in stools

Question 12

Dx of NEC

Answer 12

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

Question 13

Pneumatosis Intestinalis

Answer 13

Hydrogen gas within the bowel wall -Linear streaking pattern (“hallmark” of NEC) -Bubbly pattern

Question 14

Portal venous gas

Answer 14

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

Question 15

Pneumoperitoneum

Answer 15

Free air in the peritoneal cavity secondary to perforation -Falciform ligament may be outlined (“football” sign) SURGICAL EMERGENCY

Question 16

Stage I: suspected NEC

Answer 16

Systemic: nonspecific– apnea, bradycardia, lethargy, temp instability Intestinal: feeding intolerance, gastric residual, guiac + stool Radiologic: normal or nonspecific

Question 17

Stage II-A: Mid NEC

Answer 17

Systemic: similar to stage I Intestinal: abdominal distension, no BS, +/- tenderness, gross blood in stool Radiographic: ileus w/ dilated loops w/ focal pneumatosis intestinalis

Question 18

Stage II-B: Moderate NEC

Answer 18

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

Question 19

Stage III-A: Advanced NEC

Answer 19

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

Question 20

Stage III-B: Advanced NEC

Answer 20

Systemic: Generalized edema, decreased vital signs/lab values, shock, DIC Intestinal: tense, discolored abdomen with ascites Radiographic: absent bowel gas, intraperitoneal free air

Question 21

BASIC NEC Protocol

Answer 21

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)

Question 22

When to get surgical consult

Answer 22

Suspected or proven NEC

Question 23

Indications for surgery in NEC

Answer 23

Portal venous gas; pneumoperitoneum Clinical deterioration Positive paracentesis Fixed intestinal loop on serial x-rays (over 24 hours) Erythema of abdominal wall (peritonitis)

Question 24

NEC complications

Answer 24

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

Question 25

What presentation has the best prognosis?

Answer 25

Late onset NEC

Question 26

Malrotation

Answer 26

Incomplete rotation of the intestine during fetal development– genetic mutations Most common: failure of cecum to move in the RLQ

Question 27

Malro with Volvulus: Features

Answer 27

Presents within first few weeks of life BILIOUS VOMITING Acute small bowel obstruction (closed loop) Early: irritability, distended, rigid abdomen, bilious emesis, decreased stool Late: vascular compromise– bloody stools, circulatory collapse Older children: abdominal pain/asymptomatic; incomplete obstruction

Question 28

Dx: Midgut volvulus

Answer 28

Abdominal x-ray: double bubble sign– initial study of choice; diagnostic Other: Upper GI series, Barium enema

Question 29

Tx: midgut volvulus

Answer 29

Surgical emergency

Question 30

How does volvulus twist?

Answer 30

Clockwise –Untwist it counterclockwise “Turn back the hands of time”

Question 31

Volvulus procedure

Answer 31

Untwist (Detorse) the bowel Ladd procedure with appendectomy

Question 32

Omphalocele

Answer 32

congenital defect of the abdominal wall in which the bowel and solid viscera are covered by peritoneum and amniotic membrane and the umbilical cord inserts into the sac -Associated with prematurity and IUGR

Question 33

Omphalocele: associated anomalies

Answer 33

Cardiac Chromosomal: Exstrophy of the cloaca (vesicointestinal fissure) Beckwith-Wiedemann constellation of anomalies (macroglossia, macrosomia, hypoglycemia, visceromegaly, omphalocele) Cantrell’s pentalogy (lower thoracic wall malformations, ectopia cordis, epigastric omphalocele, anterior midline diaphragmatic hernia, cardiac anomalies)

Question 34

Omphalocele: initial management

Answer 34

Monitor vital signs– esp. body temp Blood glucose monitoring Cover to reduce fluid loss (dry dressings or topicals) Avoid pressure on the sac (risk of rupture) Prophylactic broad-spectrum abx

Question 35

Omphalocele: Repair

Answer 35

Primary: resection of omphalocele membrane and closure of fascia Giant: cannot close primarily– treat with topicals 2-3 months, skin will grow, attempt closure of anterior abdominal wall. Requires complex measures to achieve skin closure– use of biosynthetic materials or component separation

Question 36

Gastroschisis

Answer 36

Defect in anterior abdominal wall through which the intestinal contents freely protrude No overlying sac and size of defect is usually

Question 37

Gastroschisis: Tx

Answer 37

Urgent surgical repair -Vigorous fluid resuscitation (evaporative losses) -Possible primary surgical closure at birth (preferred) -Intestinal function does not return for weeks– requires TPN, followed by feeding advancements

Question 38

Gastroschisis: thick, swollen bowel

Answer 38

Cannot reduce primarily Plastic spring-loaded silo placed on bowel and secured beneath fascia or sutured silastic silo Covers bowel, allows for graduated reduction on daily basis as edema decreases Surgical closure occurs within 1-2 weeks