GI/Bili Flashcards
What is Liley curve
measures amniotic fluid concentration of bilirubin by means of spectrophotometry.
What is the most common condition requiring surgery in infancy
pyloric stenosis
Associated with T21
Possible cause of breastmilk jaundice
- Mutations in the UGT1A1 gene
- High levels of beta-glucuronidase.
consider other non-hemolytic causes of prolonged hyperbilirubinemia, need not investigate for them unless jaundice does not resolve by 12 weeks of age
Factors that worsen normal physiologic jaundice (5)
- prematurity
- sequestered blood
- delayed establishment of feedings
- maternal meds
- DDC
Duration of breastmilk jaundice
normalize over 4-12 weeks
can reach 20-30 mg/dl by 2 weeks
Causes of pathologic jaundice
Onset before 24 hrs, inc >0.5 mg/dl/hr (>5mg/dl/day), Jaundice > 8 day for term 14 days preterm, DB >1mg/dl
- Increased production
* hemolytic
* enzyme def- G6PD, PK
* membrane defect - decreased clearance: gilbert
- impaired conjugation: crigler-najjar
- increased enterohepatic circulation:breastmilk and breastfeeding jaundice
Long term consequences of kernicterus
- extrapyramidal (choreoathetosis)
- Sensorineural hearing loss
- gaze palsies
- dental dysplasia
greatest risk with rapid rate of increase
Phototherapy depends on (4)
- spectrum of light- blue (460-490 nm)
- irridiation- 30uW/cm2
- surface exposed
- distance of infant from light- 12-16 in/30-40 cm
It significantly increases surface area of the small intestine
Villi and microvilli
covered by columnar epithelial cells at tips- absorbtive cells, crypts- secretory
Part of the bowel that mainly absorbs calcium and iron
Duodenum
- 80-100% absorb calcium via active transport
- Also initiates digestion
- production of GI hormones
Parts of the bowel that absorbs calcium
- Duodenum via active transport
- Jejunum via concentration gradient
What are the location of nutrient absorption in the bowel
Specialized function of the distal ileum
Absorption of:
1. Vit B12 (needs intrinsic factor)
2. Zinc
3. Bile acid
Bile salts: not reabsorbed can cause diarrhea and impair Na and H2O
what GI hormone cause delayed in gastric emptying
glucagon peptide I and petide YY
stimulated by lipids in the ileum
longer transit time, nutrient absorption in small intestine
Function of the ileocecal valve
- regulates fluids, electrolytes, nutrient
- Prevents reflux of colonic material incl bacteria
Greatest absorption of water and sodium in the GI tract
Colon
tightest intrercellular junction and slowest transt time
morbidities/ complication of short bowel syndrome
- catheter related blood stream infection- E coli and enterococci
- Cholestasis
- Growth failure
- Small bowel bacterial overgrowth (SBBO)
CLABSI- d/t leaky gut mucosal barrier
Strategies to reverse cholestasis
- lipid reduction (1mg/kg 1-3/wk)
- lipid modification (SMOF/omegaven)
- advancement enteral feeds
Lipid supplement cannot be stopped d/t risk essential FA def
Antibiotic therapy for SBBO
Metronidazole
Ciprofloxacin
Red flags for cholestasis (3)
- jaundice >2 weeks
- hepatomegaly
- pale stools/diarrhea
Obtain fractionated bilirubin
Identifiable causes of cholestasis
- from most common
1. biliary atresia
2. genetic/metabolic: A1AT, alagille synd, CF
3. Idiopathic/transient neonatal cholestasis
4. PNAC
Direct bilirubin level assoc with cholestasis
- first 5 days: >0.3-0.4 mg/dl
- 10% of TB
Differential for GGT >150 U/L
- Biliary atresia
- choledochal cyst
- A1AT def
- CF
Differential for GGT <125 U/L
- PFIC (progressive familial intrahepatic cholestasis I, II)
- Inborn errors of bile acid synthesis
- panhypopit
Ideal timing for kasia procedure
Done before 30-45 days
chances for post-op bile flow, avoid/delay liver transplant
Evaluation for cholestasis
Most frequent indication for pediatric liver transplant
Biliary Atresia
- AR d/o associated with cholestasis
- Have hepatocyte retention of polymers mutant Z protein
- risk for early emphysema
A1AT deficiency
- AD d/o associated with cholestasis
- Mutation with Jagged1 gene
- Clinical features:
* bile duct paucity
* cong heart dis (right sided)
* dysmorphic facies- triangular face, broad forehead, deep set eyes, sm pointed chin
* ocular post embryotoxon
* butterfly vertebrae
* renal anomalies
Alagille syndrome
What is the hallmark of clinical surgical abdominal emergencies
Bilious emesis
What is the most common site of gastric perforation
Greater curvature
Abd XR: pneumoperitoneum, NG in the pelvis
Sx Acute abdomen, lethargy, apnea, RDS, bloody output from NG
Mx: Exlap, gastrostomy
It is due to lack of recanalization of duodenum
Duodenal atresia
- normally happens 8-10 weeks GA
- Dx: Abd XR: double bubble (distended stomach and prox duodenum); +/- bilious output
- Mx: gastric decompression, TPN, ECHO
- Repair not an emergency
It is the most severe complicaion of intestinal malrotation
Midgut volvulus
- Incidence highest first 2 months
- Sx: feeding intolerance and bilious emesis, bloody stools, late abd distension
- pathophysiology: obstruction and vascular compromise
What is the normal location of:
a. duodenojejunal junction
b. ilocecal valve
a. Left upper quadrant
b. right lower quadrant
In malrotaton: duodenojejunal: midabdomen, ileocecal valve: RUQ
Gold standard Dx for malrotation/ volvulus
UGI
(corkscrew sign)
Ultrasound: whirlpool sign by superior mesenteric vessels
What are the steps of the Ladd procedure
- Devolvulizing the midgut
- Adhesiolysis- separate duodenaljejunal junc and ileocecal
- Verticalizing the duodenum
- Performing appendectomy
- Replacement of the small bowel on the right hemi-abdomen and the colon on the left hemi-abdomen
done when no sigificant ischemia
What is pathology in small bowel atresia
Vascular occlusion
* can involve mesentery based on extent
True or false:
Passage of meconium rules out small bowel atresia
False
* Its commonly seen symptom failure to pass meconium
Factor associated with inc M&M prematurity, other malformation, multiple atresia (can lead to short bowel)
What is the common site for spontaneous perforation (SIP)
terminal ileum
Dx: Abd XR pneumoperitoneum w/o NEC
No reason, no vascular compromise
More common in males
risk factor: perinatal use and postnatal indomethacin, preeclampsia
Goal mgt of SIP
for <1kg: Percutaneous drain at bedside to:
1. release pressure- eliminate hypoperfusion
2. outlet spilled intestinal content
For >1kg: Laparotomy (Primary closure vs temp ostomy)
Long term consequence: enterocutaneous fistula, stricture
True or false: NEC exclusively occurs in preterm infants
False
* 5% of preterm<30 wks
* 10% of term (from hypoperfusion- CHD, sepsis)
findings: intestinal ischemia leading to damage to intestinal mucosa, bacterial invasion, sepsis
- poor mucin production overpermeability of intercellular junction
- risk factors: H2 blockers, nonhuman milk, hyperosomolar meds/formula
NEC staging and mgt
What are the parameters to determine need for exploration (SIP/NEC)
- worsening acidosis
- inc need cario-resp support
- worsening coagulopathy
- inc erythema/ bluish discoloration
Rationale: ischemic (not necrotic) intestinal tissue keeps the patient in a vicious circle
Signs of esophageal atresia
early postnatal period:
* difficult feeding
* excessive oral secretions
* cyanosis/ apnea during feeds
Prefer Dx test: flexible esophagoscopy/ bronchoscopy
UGIS after surgical repair- leak and stricture
Ultrasound finding for hypertrophic pyloric stenosis
Thickness: 3mm
Length: 15 mm
What are the functions of the GI tract
What is the GI cellular origin and function
function at maturity
Endoderm: digestion and absorption
Mesoderm: muscle
Ectoderm: enteric nervous system-Auerbach plexus is between muscle layers, Meissner plexus adjacent mucosal layer.
What are the sections of the GI tract embryologically
common sources of blood supply, innervation, and lymphatic drainage with those derived from the same precursor
Foregut: celiac artery
Midgut: superior mesentery artery
Hindgut: inferior mesentery artery
What are the ultrasound findings of biliary atresia
- sclerosed bile ducts
- absence of a gallbladder
- “triangular cord” sign
Findings in chylous ascites
- milky fluid
- elevated triglyceride
- cell count with lymphocyte predominance
- low glucose.
Predictors of outcome of CDH
1.Degree of pulmonary hypoplasia
* Lung to head ratio (<0.6)
* Observed vs expected total lung volume
2. Pulmonary hypertension
3. involvement of the liver
4. Prematurity
Delivery room mgt of CDH
- place a NGT soon after delivery for decompression of the stomach and intestines
- prompt intubation for respiratory distress
Goals in vent setting: PIP<25, preductal sats >70%
What are the fetal predictors of outcome of CDH
- Associated anomalies
- Extent of lung hypoplasia
- Position of the liver- liver up worst prognosis, highly predictive of ECMO
LHR and survival
* >1.35- 100%
* 1.35-0.6 - 61%
* <0.6- no survival
observe/expectrd LHR
<25% severe, survival 10%liver up, 25% liver down
<15 with liver up 100 mortality
long term complications of CDH
- sev pulm hypoplasia
- pulm htn
- chronic lung disease
- neuro cog delay
- hearing loss- can be late
- chest wall deformity
- scoliosis
- poor growth
- hernia reoccurence
What is the most common primary hepatic malignancy in childhood
Hepatoblastoma
- usually isolated, but may be associated with Beckwith-Wiedemann syndrome, isolated hemihyperplasia, familial adenomatous polyposis coli, or trisomies.
- Treatment with initial surgical resection versus neoadjuvant chemotherapy is determined by risk stratification based on extent, location, and histology.
What is the serum marker for hepatoblastoma
Serum α1-fetoprotein (AFP)
can be a useful marker for response to treatment
useful marker for response to treatment
How does phototherapy work for hyperbilirubinemia
- structural/geometric isomerization- Lumirubin- irreversible excreted via bile and urine (major contributor to the lowering of total serum bilirubin)
- Photo isomerization- reversible (hydrophilic, reduce the exposure of the brain to the toxic, lipid-soluble configuration).
- Photo oxidation
