Approach to the Yellow Baby Flashcards

1
Q

what are the functions of the liver?

A

Factory - produces many important proteins and enzymes for the body

Makes clotting factors – when liver not working your blood doesn’t clot as it should do

Liver play important role is absorption, digestion and metabolism of almost all food types we consume, you need bile to help you absorb fat and also plays essential role in digestion and absorption of fats, proteins and carbohydrates

storage organ for glycogen for glucose storage and for fat storage and some essential proteins like albumin

excretion and clearance of toxic products of our body, metabolism and excretion fo drugs and other toxic products to our body and if the liver fails we see a build up of toxic products in the body

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2
Q

Liver “function” tests (LFTs) - what are they?

(gorup of blood tests)

A
  • Bilirubin - Total bilirubin and “Split” bilirubin – Direct (conjugated) + Indirect (unconjugated)
  • ALT/AST (alanine aminotransferase/aspartate aminotransferase)
  • Alkaline phosphatase
  • Gamma glutamyl transferase (GGT)
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3
Q

LFTs dont tell you how well the liver in functioning but rather it is damaged

When do the following change:

  • Bilirubin
  • ALT/AST (alanine aminotransferase/aspartate aminotransferase)
  • Alkaline phosphatase
  • Gamma glutamyl transferase (GGT)
A
  • Bilirubin - Bilirubin only goes up if damage
  • ALT/AST (alanine aminotransferase/aspartate aminotransferase) - Elevated in hepatocellular damage (“hepatitis”)
  • Alkaline phosphatase - Elevated in biliary disease
  • Gamma glutamyl transferase (GGT) - Elevated in biliary disease
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4
Q

Tests to assess liver function how should it be done?

A
  • Coagulation - Prothrombin time (PT)/INR and APTT
  • Albumin - how liver is making protein
  • Bilirubin
  • (Blood glucose)
  • (Ammonia)

If liver failure more advanced then you can get hypoglycaemia or elevated ammonia but tend to be later features of liver failure

Simplest measure of liver function if test clotting and look at albumin

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5
Q

What are the Clinical manifestations of paediatric liver disease?

A
  • JAUNDICE - Most common presentation of liver disease in children is jaundice
  • Incidental finding of abnormal blood test
  • Symptoms/signs of chronic liver disease
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6
Q

what are the Signs of Chronic Liver Disease in Children?

A

+ Growth failure

Same as they are in adults

One that is different to adults is growth failure, FTF – not seen in adult patients

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7
Q

what is jaundice?

A

= yellow discolouration of skin and tissues due to accumulation of bilirubin

  • Usually most obvious in sclera (Yellow of eye is true distinction for jaundice compared to other causes of yellow skin like eating lots of orange carrots (carotenemia))
  • Usually visible when total bilirubin >40-50 umol/l
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8
Q

Diagnosis of infant jaundice dependent on what?

A
  • Understanding bilirubin metabolism
  • Age of the infant
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9
Q

Bilirubin metabolism - what is the process?

A

Starts with red cells that have reached end of life and broken down to be recycled by body

Broken down particularly in the spleen

Globin broken to amino acid

Iron reused to make new haem

Haem broken to biliverdin

Stercobilin gives stool its colour (faecal pigment)

Excreted in kidney in form of urine

Some goes back to liver

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10
Q

Pre-hepatic jaundice, Intrahepatic jaundice and Post-hepatic jaundice (cholestasis) - is bilirubin conjugated or not?

A
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11
Q

Pre-hepatic jaundice, Intrahepatic jaundice and Post-hepatic jaundice (cholestasis) jaundice - what are the causes?

A

Problem lies in the bile getting out of the liver into the small bowel to be excreted, tends to be an obstructive process

Pre-hepatic – cause of haemolysis and bilirubin production, making too much bilirubin

Hepatic – mixed picture due to liver disease, problem in liver, not conjugating it as much as it should do and also not excreting it into the bile effectively

Post-hepatic – cholestatic process which there is an obstructive process stopping bile getting out, Problem lies in the bile getting out of the liver into the small bowel to be excreted, tends to be an obstructive process

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12
Q

Understanding how bilirubin __________ and processed in body helps differentiate in the pathway where the body is coming from

A

metabolism

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13
Q

Neonatal jaundice – what are the different classifications by age?

A

Early (<24 hours old):

  • Always pathological
  • Causes: Haemolysis, Sepsis (infectious process)

-Intermediate (24hrs – 2 weeks) (most common)

•Causes: Physiological, Breast milk, Sepsis, Haemolysis

Prolonged (>2 weeks) (Prolonged most likely to be pathological rather that physiological)

•Causes: Extrahepatic obstruction, Neonatal hepatitis, Hypothyroidism, Breast milk

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14
Q

what is “Physiological” jaundice?

A
  • Shorter RBC life span in infants (80-90 days)
  • Relative polycythaemia (high total red cell count)
  • Relative immaturity of liver function
  • Unconjugated jaundice (Prehepatic jaundice)
  • Develops after first day of life (Takes time for red cells to build up)

Excess red cell breakdown and immature liver function

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15
Q

what is Breast-milk jaundice?

A
  • Exact reason for prolongation of jaundice in breastfed infants unclear
  • Unconjugated jaundice
  • Can persist up to 12 weeks

Closely linked to physiological jaundice

Breast fed infants more likely to be jaundice than formula fed

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16
Q

Why do we worry about assessing infants with jaundice?

A

Kernicterus

17
Q

what is Kernicterus and what is the process causing it?

A
  • Unconjugated bilirubin is fat-soluble (water insoluble) so can cross blood-brain barrier
  • Neurotoxic and deposits in brain

Basal ganglia in brain

Avoidable condition

Can only occur with high levels of unconjugated jaundice, cant get it with conjugated jaundice as conjugated bilirubin cannot cross the BBB

18
Q

whata re the consequences of Kernicterus?

A
  • Early signs – encephalopathy – poor feeding, lethargy, seizures
  • Late consequences – severe choreoathetoid cerebral palsy, learning difficulties, sensorineural deafness

Severe long term consequences

19
Q

what is the treatment for unconjugated jaundice?

A

Phototherapy

  • Visible light (450nm wavelength) (not UV) converts bilirubin to water soluble isomer (photoisomerisation)
  • Threshold for phototherapy in infants guided by charts

The way we avoid kernicterus developing

20
Q

how is the treatment threshold of babies with neonatal jaundice decided?

A

Different charts based on gestation of baby

exchange transfusion – remove proportion of infants blood and replace with packed red cells and dilute the blood and take out the high levels of circulating bilirubin, more aggressive treatment

21
Q

What are Other Causes of Early/Intermediate Unconjugated infant jaundice?

A

Sepsis (Any cause of infection)

Haemolysis

  • ABO incompatibility (baby different blood group form mother)
  • Rhesus disease (less common now due to rhesus screening)
  • Bruising/cephalhaematoma
  • Red cell membrane defects (e.g. spherocytosis)
  • Red cell enzyme defects (e.g. G6PD)

(Abnormal conjugation)

  • Gilbert’s disease – common, mild, slight reduction in function of UDP so less conjugation
  • Crigler-Najjar syndrome – v. rare, severe (almost complete absence of UDP = Signiant impaired of conjugation of bilirubin)
22
Q

Most infant jaundice is ________________

A

physiological/harmless

23
Q

Other Causes of Early/Intermediate Unconjugated infant jaundice:

how do we exclude sepsis, haemolysis and abnornmal conjugation?

A
24
Q

what is Prolonged infant jaundice?

A
  • Jaundice persisting beyond 2 weeks of life

•3 weeks for preterm infants

25
Q

what are the causes of Prolonged infant jaundice?

A

Conjugated:

  • Anatomical (biliary obstruction)
  • Neonatal hepatitis (liver inflammation)

Unconjugated:

  • Hypothyroidism (causes reduction in conjugation)
  • Breast-milk jaundice (jaundice may still be happening)
26
Q

Prolonged jaundice key message number 1:

  • _________ jaundice in infants is always ________ and always requires further ________
  • The most important test in prolonged jaundice is a “_____” bilirubin (distinguish weather conjugated or unconjugated jaundice)
A

Conjugated

abnormal

investigation

split

27
Q

what are the causes of prolonged jaundice – biliary obstruction?

(Stopping flow of bile out of liver)

A
  • Biliary atresia - Conjugated jaundice, pale stools
  • Choledochal cyst - Conjugated jaundice, pale stools
  • Alagille syndrome - Intrahepatic cholestasis, dysmorphism, congenital cardiac disease
28
Q

Prolonged jaundice key message number 2:

• Always assess _____ _____ in infants with prolonged jaundice

A

stool colour

Pale stool = some obstructive process going on stopping bile getting into stools

29
Q

what is Biliary atresia?

A

Congenital fibro-inflammatory disease of bile ducts leading to destruction of extra-hepatic bile ducts

Progression to liver failure if not identified and treated

Timely diagnosis critical as time to treatment determines prognosis

Most common indication for liver transplantation in children

30
Q

how does Biliary atresia present?

A
  • Presents with prolonged, conjugated jaundice
  • Pale stools, dark urine

Chalky colour stools, Obviously pale

Try see with your own eyes, e.g. photo of stool/nappy

31
Q

Biliary atresia treatment - Kasai portoenterostomy

what is it?

A

Fibroses damaged bile ducts are removed and the surgeon dissects the small bowel and takes the distal arm of the small bowel and anastomoses it onto the liver surface so bile drains from liver directly into the small intestine and the proximal arm of the small bowel into the side of that loop of small bowel so you get direct drainage of bile into the bowel

Palliative rather that curative procedure and most will need a liver transplant

32
Q

Prolonged jaundice key message number 3:

• Assessment of prolonged infant jaundice is primarily targeted at diagnosing patients with _______ ______ early

A

biliary atresia

So we can get them an early kasai procedure

Why we always check conjugated bilirubin and look at stool colour as beyond ever other diagnosis we want to find the children with biliary atresia early so we can get them an early surgical correction

33
Q

Causes of prolonged jaundice – biliary obstruction

how do you check for each of the following?

  • Biliary atresia
  • Choledochal cyst
  • Alagille syndrome
A

Alagille syndrome – look for other associated features like cardiac abnormalities and do some genetic testing for that

34
Q

What are some causes of prolonged jaundice – neonatal hepatitis?

Group of conditions that cause liver inflammation

Prolonged conjugated jaundice and they don’t haver biliary atresia then think about these

Wide variety of causes

A
  • Alpha-1-antitrypsin deficiency
  • Galactosaemia
  • Tyrosinaemia
  • Urea cycle defects
  • Haemochromatosis
  • Glycogen storage disorders
  • Hypothyroidism
  • Viral hepatitis
  • Parenteral nutrition
35
Q

Causes of prolonged jaundice – how do you investigate for neonatal hepatitis?

A

Some key tests we would do to try and differentiate cause of hepatitis picture of jaundice

Conjugated jaundice without pale stools and no evidence of structural abnormality

More specialised area

36
Q

Prolonged infant jaundice summary:

  • Always ask about stool ______
  • Most important test is a _____ bilirubin to differentiate unconjugated from conjugated jaundice
  • Conjugated jaundice always requires further investigation and should be considered ______ _______ until proven otherwise

If unconjugated you can be more relaxed about it

A

colour

split

biliary atresia