Hepatology Flashcards
What is the defintion of early jaundice?
<24 hours old
What is significant about early jaundice?
It is always pathological
If a neonate presented with early jaundice, what would be your differential diagnoses?
-
Haemolysis
- ABO incompatibility
- Rhesus disease
- Bruising/cephalhaematoma
- Hereditary spherocytosis
- G6PD deficiency
- Congenital infection/Sepsis
- Metabolic - galactosaemia
If you suspected haemolysis as a cause of early jaundice, what investigations would you do?
- Blood grouping
- G6PD assay
- Blood film
- Examination - bruising/cephalohaematoma
- Coombs test
If you suspected sepsis as a cause of early jaundice, what investigations would you do?
- Blood cultures
- Urine dipstick and culture
- TORCH screen
What is the definition of intermediate jaundice?
24hrs – 2 weeks
If a child presented with jaundice after 1 week, what would your differential diagnoses be?
- Physiological jaundice
- Breast milk jaundice
- Sepsis
- Haemolysis
- Polycythaemia
What is physiological jaundice?
Jaundice caused by:
- Low activity of glucuronosyltransferase -> normally converts unconjugated to conjugated bilirubin
- Shorter life span of fetal red blood cells (80 to 90 days)
- Relatively low conversion of bilirubin to urobilinogen by the intestinal flora
Develops after first day of life
How long can phsyiological jaundice last for?
Up to 1 month
What is breast milk jaundice?
Jaundice caused by taking breast milk - Exact reason for prolongation of jaundice in breastfed infants unclear:
- Inhibition of UDP by progesterone metabolite
- Increased enterohepatic circulation
Unconjugated jaundice
What type of bilirubin would you expect to see in physiological jaundice?
Unconjugated bilirubin
What type of bilirubin would you expect to see in breast milk jaundice?
Unconjugated bilirubin
How long can breast milk jaundice last for?
Up to 12 weeks
What is prolonged jaundice?
>2 weeks
How would you assess prolonged jaundice in a child?
- Split bilirubin
- Stool and urine colour
If a neonate presented with jaundice at 3 weeks, and serum bilirubin showed conjugated bilirubin, what would be your differential?
- Bile duct obstruction - biliary atresia, choledochal cyst
- Neonatal hepatitis syndrome - multiple causes
- Intrahepatic biliary hypoplasia - Alagille syndrome
If a neonate developed jaundice at 3 weeks, and the serum bilirubin was unconjugated, what would you differential diagnosis be?
- Prolonged Breast milk jaundice
- Hypothyroidism
- Infection
- Haemolysis
- High GI obstruction
What is biliary atresia?
Congenital fibro-inflammatory disease of bile ducts leading to destruction of extra-hepatic bile ducts
How does biliary atresia present?
- Faltering growth
- Pale urine
- Dark stools
- Hepato-(+/- spleno-)megaly
What is the risk of not treating biliary atresia?
Liver failure - time to treatment determines prognosis
How would you investigate for biliary atresia?
- Split bilirubin - conjugated bilirubin
- Stool colour
- US - contracted/absent gallbladder
- Liver Biopsy
How would you treat biliary atresia?
Kasai portoenterostomy - lopp of the jejunum is anastamosed to the cut surface of the porta hepatis, allowing bile to drain
Best results if performed before 60 days
What are Choledocal cysts?
Cystic dilatations of the extra-hepatic biliary system
How would a child with a choledocal cyst present?
- Abdo pain
- Palpable mass
- Cholangitis/jaundice
- Pale stool/dark urine
How would you investigate a suspected choledocal cyst?
- Split bilirubin
- Stool colour
- US scan
What is Alagille Syndrome?
Autosomal dominant condition, with children with traingular faces, skeletal abnormalities, congenital heart disease (PS), renal tubular disorders and intrahepatic biliary hypoplasia
If you suspected Alagille syndrome, how would you investigate?
Genotyping
What are causes of neonatal hepatitis syndrome?
- Alpha-1-antitrypsin deficiency
- Galactosaemia
- Tyrosinaemia
- Urea cycle defects
- Haemochromatosis
- Glycogen storage disorders
- Hypothyroidism
- Viral hepatitis
What can be a complication of jaundice if left untreated for too long?
Kernicterus
How would you initially approach investigating a child with conjugated hyperbilirubinaemia?
Screen for
- Infection
- Genetic causes - alpha 1 antitrypsin, CF, galactosaemia
- Metabolic causes
Abdominal US Scan
If a child with conjugated hyperbilirubinaemia had a dilated biliary tree, what would be the suspected diagnosis?
Choledocal cyst
If a child with conjugated hyperbilirubinaemia had a normal biliary tree on US scan, what would be the next step of investigation?
TBIDA radionuclide scan - determines excretion of bile from the tree - whether the bile duct is patent or not
What is kernicterus?
Encephalopathy resulting from deposition of unconjugated bilirubin in the basal ganglia and brainstem nuclei. Happens when unconjugated bilirubin exceeds albumin binding capacity
Why can unconjugated bilirubin cross the blood-brain barrier?
It is fat soluble
In acute kernicterus, how will the child change at first?
- Decreased alertness
- Hypotonia
- Poor feeding
In acute kernicterus, how can the child change in the first intial phase of lethargy, poor feeding and hypotonia?
- Irritable
- Hypertonia of extensor muscles
- Retrocolis - head drawn back
- Opisthotonus - arched back
- Seizures
- Coma
What can develop in the context of chronic kernicterus?
Choreoathetoid CP - due to basal ganglia damage
- Hypotonia, hyperreflexia, delayed acquisition of motor milestones
- Extrapyramidal – athetosis, chorea, upper limbs > lower limbs
- High frequency hearing loss
- Upward gaze
What is haemolytic disease of the newborn/ABO incompatibility?
Maternal IgG antibodies with specificity for the ABO blood group system pass through the placenta to the fetal circulation where they can cause hemolysis of fetal red blood cells which can lead to fetal anemia and HDN
What is Rhesus haemolytic disease?
Typically occurs only in some second or subsequent pregnancies of Rh negative women where the fetus’s father is Rh positive, leading to a Rh+ pregnancy. During birth, the mother may be exposed to the infant’s blood, and this causes the development of antibodies, which may affect the health of subsequent Rh+ pregnancies.
What test could you do to look for ABO incompatibility?
Coomb’s test
What is the the incidence of biliary atresia?
1/15000
How common is conjugated hyperbilirubinaemia in a neonate?
Rare
What type of jaundice does haemolysis cause?
Unconjugated jaundice - overloads albumin carrying capacity and liver processing capacity
Why does hepatic and post-hepatic jaundice cause pale stools and dark urine?
Bile doesn’t get into the intestine -> no stercobilin to make faeces brown
Conjugated bilirubin is water soluble and accumulates, moving into the blood stream -> carried to kidneys where it can cross glomerulus -> excreted in urine, making it dark
How would you treat jaundice?
- Treat the cause
- Hydrate and feed
-
Determine severity of hyperbilirubinaemia
- Mild - moderate: Phototherapy
- Severe: Exchange transfusion
- Immunoglobulin
How do you determine whether to use exchange transfusion or phototherapy?
- Plot bilirubin on gestation specific chart
- Determine Rate of change
What form of therapy would you use in the context of rapidly rising serum bilirubin?
Exchange transfusion
How would you assess jaundice in a neonate?
- Assess severity
- Determine gestation
- Determine age
- Are they well or unwell
- Risk factors
- Needing treatment
What type of jaundice can congenital infection cause?
CONJUGATED/UNCONJUGATED - depending on cause
What type of jaundice is caused by bile duct obstruction (e.g. biliary atresia/choledocal cyst)?
CONJUGATED - bile backs up - dark urine pale stool
What type of jaundice is caused by neonatal hepatitis syndrome?
CONJUGATED
What type of jaundice can occur in hypothyroidism?
Unconjugated
What type of jaundice can occur in high GI obstruction?
Unconjugated
What are causes of unconjugated prolonged jaundice?
- Prolonged Breast milk jaundice - most common
- Haemolysis
- Infection
- Hypothyroidism
- High GI obstruction
