NCC content Flashcards
(94 cards)
1
Q
When does the primordial gut form?
A
during the 4th week of gestation
2
Q
What 3 parts make up the primordial gut?
A
- foregut
- midgut
- hindgut
3
Q
What does the foregut become?
A
- *the cranial part**
- oral cavity, pharynx, tongue, tonsils, salivary glands
- upper and lower respiratory system
- esophagus
- stomach
- duodenum
- liver and biliary apparatus, gallbladder, pancreas, spleen
4
Q
What circulation supplies the foregut?
A
-celiac artery
5
Q
What does the midgut become?
A
- small intestine
- ascending colon and large portion of transverse colon
- cecum
- appendix
6
Q
What circulation supplies the midgut?
A
superior mesenteric artery
7
Q
Describe the physiologic umbilical herniation of the midgut.
A
- During the 6th week: rotation 90 degrees counterclockwise, goes around axis of superior mesenteric artery
- Returns to abdomen by week 10: small intestine goes back in first and occupies central region; large intestine rotates 180 degrees counterclockwise and occupies the rest of the abdomen
8
Q
What does the hindgut become?
A
- distal third of the transverse colon
- descending colon
- sigmoid colon
- rectum and upper part of anal canal
- epithelium of the urinary bladder
- urethra
9
Q
What circulation supplies the hindgut?
A
inferior mesenteric artery
10
Q
How is age of presentation of NEC related to gestational age at birth?
A
inversely
FT will present more quickly, PT 3 weeks or so
11
Q
Pathogenesis of NEC for PRETERM
A
precise pathogenesis remains unknown
MULTIFACTORIAL
-intestinal immaturity (digestion, absorption, motility)
-abnormal microbial colonization
-immature intestinal epithelial barrier (preterm babies have wider junctions that allow bacteria to penetrate gut)
-feedings (aggressive feedings, formula feedings)
-inflammatory process
12
Q
Pathogenesis for NEC for TERM
A
precise pathogenesis remains unknown
-hypoxia-ischemia (acute primary ischemic injury to bowel)
aka kids with cyanotic heart disease, low apgars, chorio, exchange transfusion for hyperbili
13
Q
GI symptoms of NEC
A
- abdominal distention in 70% (compromises GI blood flow)
- feeding intolerance
- emesis (bilious or not)
- bloody stools
- abdominal wall erythema or bluish discoloration
14
Q
Systemic symptoms of NEC mimicking sepsis
A
- apnea/bradycardia
- poor perfusion
- lethargy
15
Q
What is diagnostic for NEC?
A
pneumatosis or portal venous gas
16
Q
What lab abnormality if characteristic for NEC?
A
hyponatremia
17
Q
What is pneumatosis?
A
intramural air
-accumulation of hydrogen gas in the bowel wall from fermentation of carbohydrates by gas-producing organisms
18
Q
What X-rays should I get for NEC?
A
- left lateral decub (really helps with determining pneumoperitoneum) aka liver side up
- A/P
19
Q
Radiographic findings for NEC
A
- ileus
- pneumatosis
- dilated loops
- thickened bowel wall
- pneumoperitoneum
- portal venous gas
20
Q
What is the football sign?
A
appearance of the falciform ligament that should not usually be visible?
21
Q
What is the staging system for NEC called?
A
Bell Staging Criteria
22
Q
What is Stage I of Bell Criteria?
A
-Suspected NEC (temp instability, a/b, gastric residuals, mild abd. distention, bloody stool, normal or mild ileus on X-ray)
23
Q
What is Stage II of Bell Criteria?
A
-Definite NEC (radiographic evidence that NEC is present)
24
Q
Compare Stage IIA and Stage IIB of Bell Criteria.
A
- Stage IIA: mild NEC (prominent abd. distention, absent BS, grossly blood stools, ileus or dilated bowel loops with focal pneumatosis on X-ray)
- Stage IIB: moderate NEC (mild acidosis, thrombocytopenia, abd. wall edema, tenderness, extensive pneumatosis, possible portal venous gas, early ascites on X-ray)
25
What radiographic sign is required for Stage IIIB of Bell Criteria?
pneumoperitoneum (free air)
26
Compare Stage IIIA and Stage IIIB of Bell Criteria.
-Stage IIIA: advanced NEC (resp & metabolic acidosis, mechanical ventilation, hypotension, oliguria, DIC, worsening wall edema & erythema with induration, prominent ascites with persistent bowel loop but no free air on X-ray)
Stage IIIB: advanced NEC (vital sign & lab evidence of deterioration, shock, evidence of perf. and pneumoperitoneum on X-ray)
27
Medical management for NEC
- NPO
- decompression (to help maximize blood flow to intestines by decreasing dilatation)
- blood culture and abx (anaerobic coverage with free air)
- serial abdominal X-rays, especially in first 24 hrs
28
Surgical management for NEC
- peritoneal drainage (many eventually require surgery anyway and there is no way to assess necrosis; more likely to form strictures)
- exploratory lap (may be better with intestinal necrosis)
29
Absolute indication for surgery with NEC
- pneumoperitoneum
- clinical deterioration despite medical treatment
- abdominal mass with persistent intestinal obstruction or sepsis
- development of intestinal stricture
30
Spontaneous ileal perforation vs. NEC
SIP: focal perforation not associated with infection and inflammation; presents early in life, most commonly occurs in terminal ileum
NEC: perforation presents at 3 week mark or so and associated with all the bad things
31
Risk factors for SIP
- postnatal steroids
- indocin
- vasopressor use
32
Pathogenesis/Presentation of SIP
- intestinal mucosa is robust and viable, no inflammation
- submucosa thins, smooth muscle starts to have necrosis which leads to fragility, and a hole develops
- these babies are fine one day and suddenly sick the next; lack of infectious symptoms
33
Diagnosis of SIP
pneumoperitoneum on xray
34
Pathogenesis of umbilical hernia
- protrusion of tissue or visor through the umbilical fascial ring
- ring fails to close completely
35
Incidence of umbilical hernia
- more commonly associated with preterm infants and LBW infants
- associated with trisomy 21, congenital hypothyroidism, Beckwith-Wiedemann syndrome
36
Management of umbilical hernia
- diagnosed by physical exam
- majority spontaneously close if defect is small by 3 years of age
- surgery recommended if hernia persists after 4 to 5 years of age
37
Gastroschisis appears on which side of the cord?
right side
38
Etiology of gastroschisis
unknown for the most part, current thinking is there was a vascular accident during embryogenesis
39
What prenatal lab work suggests gastroschisis?
elevated maternal serum alpha-fetoprotein
40
Gastroschisis preoperative management
- avoid bag/mask ventilation
- bowel bag
- right side-lying position
- NPO, decompression
- increase total fluids
- antibiotics
41
Gastroschisis surgical management
- primary closure (preferred)
| - staged closure with prosthetic silo
42
Omphalocele etiology
unknown, but theories:
- incomplete return of bowel into abdomen
- incomplete closure of anterior abdominal wall
43
Omphalocele association with other anoamlies
- 50-70% will have associated anomalies
| - Beckwith-Wiedemann should be considered
44
What prenatal lab suggests omphalocele?
elevated maternal serum alpha-fetoprotein
45
Omphalocele management vs. gastroschisis
- increased IVF, but not as much if sac hasn't ruptured
- screening echo
- chromosomes
46
omphalocele surgical management
- primary closure
| - staged closure
47
Omphalocele postoperative management
-watch LFTs if liver was out; could suggest occlusion of hepatic or portal veins
48
Polyhydramnios is more common with...
proximal obstructions
49
Abdominal distention is more common with...
distal obstructions and TEF (lower type of obstruction)
50
Bilious emesis is more when...
obstruction is distal to the ampulla of Vater
51
Early onset vs. late onset bilious emesis
```
early = higher obstruction
late = lower obstruction
```
52
when should a baby pass meconium by?
94% by 24 hrs of age
| 99.8% by 48 hrs of age
53
Hypertrophic pyloric stenosis
hypertrophy of pylorus resulting in stricture of the outlet from the stomach to the small intestine
54
Pyloric stenosis etiology
unknown, hereditary component
55
pyloric stenosis incidence
- first born more often affected
- 4:1 male to female predominance
- more common amount caucasian infants
56
Pyloric stenosis clinical presentation
- nonbilious vomiting, usually around 2-6 weeks of age that become projectile with time
- signs/symptoms of dehydration, poor weight gain
57
pyloric stenosis diagnostic evaluation
- upper GI or abdominal ultrasound
- "olive-shaped" mass in RUQ below liver
- "string sign" (barium lining elongated pyloric channel)
- "double track" sign (contrast caught between mucosal folds of hypertrophied area)
58
pyloric stenosis postoperative care
- warn parents that emesis can still occur after surgery until function has returned
- NEVER place NG tube and risk perforating surgical site
- feedings start 6 to 8 hrs post-op
59
Duodenal atresia incidence
- most common type of small bowel atresia
- females more commonly affected than males
- high incidence of associated conditions; 30% infants associated with trisomy 21
60
Pathogenesis of duodenal atresia
- congenital obstruction of duodenum, usually distal to ampulla of Vater
- etiology unknown; thought to be from failure of recanalization of the duodenum during 8th week of gestation
- may be atresia, stenosis, web, Ladd's bands wrapping around or annular pancreas wrapping around
61
Duodenal atresia postoperative management
- delayed gastric emptying across reanastomosis site is normal
- the higher the lesion, the more likely there will be a delayed response in function
62
Jejunal and ileal atresia
- failure of the lumen of the bowel to form properly
| - thought to be d/t mesenteric vascular insult with subsequent necrosis and reabsorption of the affected segments
63
Jejunal/ileal atresia incidence
-usually presents as an isolated defect
64
Jejunal and ileal atresia types
- 5 different types
- I and II have normal bowel length, III and IV have shorter length and thus more trouble feeding
- Type IIIB: apple peel or christmas tree - usually a familial form
65
jejunal and ileal atresia on xray
- "triple bubble" in proximal jejunal atresia
| - gas or fluid-filled dilated loops of bowel with scant amounts of gas distal to the obstruction
66
Meconium ileus
mechanical obstruction of the distal lumen d/t meconium
67
Meconium ileus etiology
unknown; theories:
-d/t to hypo secretion of pancreatic enzymes or abnormal viscous secretions from the mucous glands of the small intestine
68
meconium ileus incidence
-majority of cases are associated with cystic fibrosis
69
meconium ileus xray
- may show peritoneal calcifications from earlier perfs
- dilated proximally, microcolon distally, no air in rectum
- "soap bubble" appearance
70
Contrast enema for meconium ileus
can be diagnostic and therapeutic if it's hyperosmolar
71
Meconium ileus management
- if prenatal/postnatal perforation is present or enemas are not effective in evacuating meconium, then surgery is indicated
- repeat enemas increased the risk for intestinal perforations
72
Meconium ileus postoperative management
- need pancreatic enzymes when beginning feeds
- Genetic testing: DNA (80-90% sensitive) or sweat chloride
- pulmonary toilet: CPT, aerosols, humidity
- can develop volvulus, perforation with peritonitis, infection
73
Meconium Plug syndrome
mechanical obstruction of the distal colon/rectum due to thick, inspissated meconium
- lack of good colonic motility
- etiology is unknown; associated with mag therapy, IDM, prematurity, hypothyroidism, hypotonia and sepsis
74
Meconium plug diagnostic evaluation
- xray: dilated loops of bowel and few air fluid levels
- water soluble contrast enema can be diagnostic and therapeutic
- can be difficult to differentiate from Hirschsprung's and meconium ileus
75
Meconium plug management
- enemas
- digital rectal exam
- surgery if nothing is successful in passing meconium
76
Malrotation/volvulus
abnormal rotation and fixation of intestines during 7th to 12th week of gestation
77
Malrotation/volvulus etiology
unknown; occurs when intestines do not rotate and/or the mesentery does not fixate during embryologic development
78
Malrotation/volvulus incidence
-associated with abdominal wall defects, intestinal atresia, imperforate anus, cardiac anomalies, and trisomy 21
79
Malrotation/volvulus incidence
- most cases present during 1st month
- bilious emesis, abd. distention, tenderness, bloody emesis or stools
- signs of shock and sepsis if necrotic
80
Malrotation/volvulus surgical management
- laparotomy (Ladd's procedure)
| - appendectomy commonly done to r/o appendix as the cause of abdominal pain later in life
81
Hirschsprung's disease etiology
| aka congenital megacolon or aganglionic megacolon
-caused by failure of migration of neural crest neuroblasts to the distal portion of the colon
82
Hirschsprung's incidence
- occurs predominantly in white males
- 1/3 will have positive family history
- associated anomalies not common
- increased risk of hearing loss, ocular neuropathies, and decreased peripheral nerve function
83
Hirschsprung's diagnostic evaluation
- x-ray nonspecific
- barium enema: transition zone
- anal manometry
- rectal biopsy: definitive diagnosis
84
Hirschsprung's surgical management
- staged repair: colostomy with later pull-through procedure
| - complete pull-through repair: laparoscopic surgery
85
Hirschsprung's prognosis
- dysmotility of colon: stooling abnormalities-constipation or incontinence
- rectal stenosis
- stricture formation
86
Anorectal malformations
wide spectrum of abnormalities characterized by stenotic or atretic anal canal
87
anorectal malformation etiology
-failure during embryonic development of differentiation of the urogenital sinus and cloaca
88
anorectal malformation incidence
- more common in males
| - associated with GU, vertebral, CV, and esophageal atresia with TEF (THINK VATER/VACTERL)
89
Anorectal malformation: high vs. low lesions
any lesion above pubococcygeal line is high, below is low
90
low anorectal malformation
- rectum has descended below the sphincter muscle complex
| - rarely a fistula
91
high anorectal malformation
- located above the sphincter muscle
| - usually has a fistula
92
anorectal malformation diagnostic evaluation
- xray of sacrum (Wangensteen-Rice technique: inverted lateral radiograph)
- MRI/echo
- VCUG
- perineal and spinal ultrasounds
93
anorectal malformation preoperative management
- serial urinalysis to check for fistula
| - observe closely for enterocolitis or possible perforation
94
urinary incontinence with anorectal malformation
-higher likelihood if the lesion is high
