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 or >20% of TB
- 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
photoherapy work by structural isomerization- irreversible
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