Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Paediatrics > Approach to the yellow baby > Flashcards

Approach to the yellow baby Flashcards

1
Q

What are some of the functions of the liver?

A

Produces blood clotting enzymes

Absorption of foods (particularly fat)

Storage of glcogen (and albumin)

Metabolism and excretion of drugs and toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is measured when doing liver function tests?

A

Bilirubin - total + split (conjugated + unconjugated)

ALT / AST

Alkaline phosphatase

Gamma glutamyl transferase (GGT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does raised ALT/AST indicate?

A

Hepatocellular damage

damage to hepatocytes - eg. in hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do raised Alkaline phosphatase and Gamma glutamyl transferase (GGT) indicate?

A

Biliary disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Since LFT’s are often more an indicator of damage of the liver rather than good function, what would you measure to test the function of the liver?

A

**Coagulation - PTT (prothrombin time), APTT

*Albumin

Bilirubin

Blood glucose / Ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the cardinal sign of liver disease in children?

A

Jaundice

Additional symptoms of liver disease rarely seen without jaundice, otherwise liver disease mainly seen incidentally on tests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some features of liver disease in children that isn’t seen in adults?

A

Growth failure (failure to thrive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What causes jaundice? Where is it most visible?

A

Buildup of bilirubin gives a yellow tinge, usually when bilirubin is above 40 umol/L

Most visible in sclera of eyes

Also seen if apply pressure and blanch the skin over the sternum (should go white, but is there a yellow tinge?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the steps of bilirubin metabolism?

A
  1. Breakdown of erythrocytes into unconjugated bilirubin in RES and spleen
  2. Unconjugated bilirubin bound by albumin, transported to liver where glucuronic acid is added to make it conjugated bilirubin
  3. Conjugated bilirubin excreted in bile and converted to urobilinogen
  4. Urobilinogen either excreted in stool, by kidneys, or reabsorbed vie enterohepatic circulation and reincorporated into bile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is bilirubin water soluble?

A

Unconjugated bilirubin is not water soluble, needs to bind albumin to be transported

Conjugated bilirubin is water soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is raised unconjugated bilirubin a sign of?

A

Pre-hepatic jaundice

The problem lies with RBC metabolism and breakdown, making too much bilirubin to deal with

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a mix of raised unconjugated and conjugated bilirubin a sign of?

A

Intrahepatic jaundice

Liver dysfunction is causing it to be unable to excrete bilirubin into the bile effectively, problem is with the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is raised conjugated bilirubin a sign of?

A

Post-hepatic jaundice: cholestasis

Bilirubin is getting out of the liver and into the bile, but problems with biliary secretion are causing a buildup of conjugated bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the different age classifications for infant jaundice?

A

Early (< 24hrs)

Intermediate (24 hours - 2 weeks old)

Prolonged (> 2 weeks old)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

If a baby is jaundiced at an early stage (< 24 hours old), what are the likely causes?

A

Always pathological**

  • Haemolysis
  • Sepsis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If a baby is jaundiced at an intermediate stage (24 hours - 2 weeks old), what are the likely causes?

A

Physiological
breast milk

  • Sepsis
  • Haemolysis
17
Q

If a baby is jaundiced at an prolonged stage (> 2 weeks old), what are the likely causes?

A

Extrahepatic obstruction
Neonatal hepatitis
Hypothyroidism

Breast milk

18
Q

What causes physiological jaundice in babies?

A

A misbalance in bilirubin metabolism is caused by:

  • HbF having a shorter lifespan than adult Hb (haemolysis)
  • Babies being relatively polycythaemic (high RBC)
  • Their livers being relatively immature

Just means there will be high bilirubin for a bit that should resolve spontaneously as liver function catches up

19
Q

In physiological jaundice, when does it develop? What type of bilirubin would be found mostly?

A

Develops after the first day of life

Mostly unconjugted bilirubin as excess haemolysis is uncompensated due to immature liver function

20
Q

What is breast milk jaundice? What type of bilirubin is seen? How long does it last?

A

Jaundice that can be seen in breast fed infants that isn’t seen in bottle fed infants. Mechanism of jaundice is unclear.

Unconjugated bilirubin

Can last for around the first 3 months of life

21
Q

What is kernicterus?

A

Serious complication of raised unconjugated bilirubin

Since unconjugated bilirubin is fat soluble it can cross the blood brain barrier, leads to toxic deposits of bilirubin in the brain (particularly basal ganglia)

22
Q

What are some of the early signs of kernicterus?

A

Encephalopathy:

  • poor feeding
  • lethargy
  • seizures
23
Q

What are some of the late consequences of kernicterus?

A

Severe choreoathetoid cerebral palsy

Learning difficulties

Sensironeural deafness

24
Q

How is raised unconjugated bilirubin treated in young babies?

A

Phototherapy

Placing the blidfolded baby under a 450nm wavelength (visible light - blue) converts unconjugated bilirubin to a water soluble isomer via photoisomerisation

(can also be done by exchange transfusion - more agressive: involves taking some of the babies blood and replacing it with other red cells)

25
Q

What are some non-physiological causes of high unconjugated bilirubin in infants?

A

Sepsis

Haemolysis (ABO incompatibility, rhesus disease, bruising, red cell membrane defects)

Genetic:

  • Gilbert’s disease (common, partial inability to conjugate bilirubin)
  • Crigler Najjar syndrome (rare, near total inability to conjugate bilirubin)
26
Q

What tests may be done in babies to find out or exclude non-physiological causes of high unconjugated bilirubin in babies?

A

Urine + blood cultures (sepsis)

Blood group + DCT (direct Coombs test) (haemolysis)

Blood film

Genetic testing

27
Q

When is infant jaundice classified as being prolonged?

A

When it lasts for more than 2 weeks

More than 3 weeks in preterm babies

28
Q

What are the main potential causes for prolonged jaundice in the infant?

A

Unconjugated:

  • Breast milk
  • Hypothyroidism

Conjugated:

  • Neonatal hepatitis
  • Biliary obstruction
29
Q

What is the most important test to do on a baby that has jaundice?

A

A split bilirubin test

Conjugated bilirubin is ALWAYS pathological so knowing whether the bilirubin is conjugated is v important

30
Q

What are the most important causes of biliary obstruction in young babies?

A

***Biliary atresia (bile can’t get out of liver - conjugated jaundice and pale stool)

Choledochal cyst (cystic malformation of bile duct, turbulent flow & blockage, conjugated jaundice and pale stool)

Allagile syndrome (intrahepatic blockage - genetic syndrome. comes with heart disease)

31
Q

When an infant has prolonged jaundice what is the most important question in their history taking? What does it tell us?

A

Stool colour

If the stool is pale there is an obstruction that is stopping the passage of bile into the stool (biliary obstruction)

32
Q

What is biliary atresia?

A

Congenital fibro-inflammatory disease of the bile ducts, starting at the extra-hepatic ducts and moving proximally

Causes obstruction of bile flow

33
Q

How does biliary atresia present?

A

Jaundice

Pale stools

Dark urine

Progresses to liver failure if untreated

34
Q

How is biliary atresia treated?

A

Kasai portoenterstomy

Remove the cystic ducts, anastamose the ileum onto the liver, anastamose the duodenum onto more distal ileum

Bile drains directly into gut afterwards. Ideally want to do the surgery before 9 weeks of age

Will eventually rely on liver transplant

35
Q

What investigations can be done when there is suspected biliary obstruction?

A

Split bilirubin

Stool colour

USS

Liver biopsy

36
Q

If the baby has prolonged conjugated jaundice, but no biliary atresia, what would be next in your DDx?

A

Neonatal hepatitis

37
Q

What are some causes of neonatal hepatitis?

A 
Alpha-1-antitrypsin deficiency
Galactosaemia 
Tyrosinaemia 
Urea cycle defects 
Haemochromatosis 
Glycogen storage disorders 
Hypothyroidism
Viral hepatitis
Parenteral nutrition

Paediatrics (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions