Pathological / Physiological Jaundice

Question 1

What is pathological jaundice?

Answer 1

Jaundice within 24h of birth, typically due to an underlying condition.

Question 2

What is physiological jaundice?

Answer 2

Jaundice after 24hs caused by breakdown of RBC

Question 3

What is the A+P of physiological jaundice?

Answer 3

• Haemoglobin within red blood cells break down into heme and globin (taken place in the spleen and liver)
• Globin turns into amino acids (protein)
• Heme turns into iron and biliverdin by heme oxygenase (an enzyme)
• Biliverdin breaks into unconjugated bilirubin by biliverdin reductase (an enzyme)
• Unconjugated bilirubin goes to the liver and attaches to albumin (to turn bilirubin from fat soluble to water soluble – conjugation).
• Conjugation needs glucose, oxygen and UDPGT – turns from unconjugated bilirubin to conjugated bilirubin to be able to pass through the colon
• Goes to the colon to then be excreted
• If still conjugated after the liver = entero-hepatic circulation occurs
• Free roaming uncoagulated bilirubin (lack of albumin) = Where some conjugated bilirubin stays in the body and is reabsorbed by blood as it becomes uncoagulated within the intestine and colon, this is reabsorbed by the skin causing jaundice.

Question 4

What are signs of jaundice?

Answer 4

Yellow skin
Lethargy
Poor feeding
Pale stools
Dark urine
250mmol/L serum bilirubin

Question 5

What are the main causes of pathological jaundice?

Answer 5

Haemolytic diseases
Metabolic disorders
Structural defects
Infection

Question 6

What are examples of disorders that cause pathological jaundice?

Answer 6

G6PD Deficiency
Hypothyroidism
T21, T18, T13
Infections - CMV, toxoplasmosis, STDs, sepsis, hepatitis, UTI

Question 7

What is kernicterus?

Answer 7

A build up of bilirubin within the brain, potentially causing seizures, brain damage like cerebral palsy and death.

Question 8

What are symptoms of Kernicterus?

Answer 8

Unconjugated bilirubin is lipid soluble, so it can pass the blood brain barrier and is neurotoxic.

Question 9

What are symptoms of kernicterus?

Answer 9

340 mmol/L SBR
Lethargic
Hypotonia
Leads into:
hypertonia
Stiffness
Seizures

Question 10

What is the name for high levels of bilirubin?

Answer 10

Hyperbilirubinemia

Question 11

How does phototherapy reduce jaundice/bilirubin?

Answer 11

Converts unconjugated bilirubin into lumirubin, which is water soluble, which can be excreted through urine.

Question 13

How long does prolonged jaundice last?

Answer 13

2 weeks +