Jaundice Flashcards

1
Q

What defines prolonged jaundice after birth

A

> 14 days if term
21 days if preterm

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

What are the causes of neonatal jaundice in the first 2 weeks of life

A

<24h: ALWAYS PATHOLOGICAL
Haemolytic anaemia (ABO/Rhesus incompatibility, G6PD deficiency, spherocytosis, pyruvate kinase deficiency)
Infection
Inborn error of metabolism
liver disease

> 24h - 2 weeks: usually physiological
Physiological (high conc. RBCs with short lifespan)
Breast milk jaundice
Infection
Haemolysis, polycythaemia
Bruising
Congenital hypothyroidism
Gilbert’s syndrome
Crigler-Najjar syndrome (glucoronyl transferase deficient or absent)

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

What are the causes of neonatal jaundice after the first 2 weeks of life

A

Unconjugated
Haemolysis: Haemolytic anaemia (ABO/Rhesus incompatibility, G6PD deficiency, spherocytosis)
Hepatic
Infection
Pyloric stenosis

Conjugated:
Hepatic: hepatitis, cystic fibrosis, cirrhosis
Obstructive: biliary atresia, bile duct obstruction, hepatitis, bile duct stones, cholecystitis, choledochal cyst, cholangitis

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

What are the causes of jaundice in older children

A

Pre-hepatic:
Malaria
SCD
G6PD deficiency
Haemolytic anaemia

Hepatic:
Infection e.g. CMV, HSV, hepatitis
Drugs
Toxins
Autoimmune hepatitis
Wilson’s disease

Post-hepatic:
Bild duct stones
Cholecystitis, choledochal cyst
Cholangitis

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

Describe the production and metabolism of bilirubin

A
  1. Bilirubin is produced as a result of haem breakdown (unconjugated, insoluble)
  2. The unconjugated bilirubin is then metabolised by liver cells to a soluble conjugated form
  3. This is excreted via the hepatic and bile ducts into the duodenum
  4. Bilirubin and bile salts in the bowel aid in absorption of fats and fat-soluble vitamins
  5. 1/2 is reabsorbed from the bowel as urobilinogen (enterohepatic circulation)
  6. Excretion in the urine or re-metabolised in the liver.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe ABO incompatibility leading to jaundice

A

Most ABO Abs are IgM and do not cross the placenta, but some group O women have an IgG anti-A-Haemolysin in their blood that can cross the placenta and haemolyse the red cells of a group A infant
Group B infants can also be affected by anti-B haemolysins
Presents with: moderate jaundice (peak 12-72h), Hb normal/slightly reduced, no hepatosplenomegaly
Coomb’s test positive

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

Describe G6PD deficiency causing neonatal jaundice

A

Seen in those from the Mediterranean, Middle-East and Far East or in Africa
Mainly affects male infants, but some females develop significant jaundice
Parents of affected infants should be given a list of drugs to be avoided as they may precipitate haemolysis

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

Describe Rh haemolytic disease causing neonatal jaundice

A

Now rare due to screening and anti-D Abs given to those at risk
Otherwise: anaemia, hydrops, hepatosplenomegaly, severe jaundice

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

Describe physiological jaundice

A

Mild or moderate jaundice
No underlying cause
Diagnosis of exclusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe breast milk jaundice

A

More prolonged and common
Unconjugated bilirubin
Increased entero-hepatic circulation of bilirubin
Benign, may last up to 12 weeks

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

What should you look for on examination for neonatal jaundice

A

Height and weight: ? Failure to thrive
Skin:
- Visible Jaundice
- Blanch the skin with a finger to see it better
- Starts on the face then spreads to the trunk and limbs
- Check with transcutaneous bilirubin meter or blood sample
- Excoriations due to pruritus
- Chronic liver disease: Spider naevi, clubbing, ascites
- Evidence of bruising e.g. cephalhaematoma (exacerbates jaundice)
Abdominal
- Hepatomegaly
- Hard liver: cirrhosis
- Splenomegaly: haemolysis, cirrhosis

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

What investigations should be done for jaundice in children

A
  1. Transcutaneous bilirubin meter or serum bilirubin within 6 hours of presentation
    - <24 hours/<25w → serum BR
    - 24 hours to 2 weeks/>35w → transcutaneous BR
    - 2 weeks → split serum BR
    - If the result is >250 μmol/L, check the result by measuring serum bilirubin

Bedside: TC bilirubin meter
Bloods: FBC (haemolysis, sepsis), Blood film, LFTs, ALP, hepatitis serology, DAT, blood culture, TFTs, osmotic fragility testing, G6PD levels, blood group of mother and baby
Other: consider CSF in infection

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

What is the management for neonatal jaundice

A
  1. Clinical assessment
  2. Measure bilirubin (transcutaneous, serum) → plot on a jaundice chart
    →reaches threshold:
  3. Phototherapy (uBR → harmless water-soluble pigment excreted into the urine)
    - Repeat serum bilirubin ever 6 hours → stable/falling → every 6-12h
    - Can be stopped once the serum bilirubin level is > 50 mmol/L below the threshold for treatment
    - Check for rebound hyperbilirubinaemia 12-18h after stopping
  4. Exchange transfusion (when bilirubin levels exceed the treatment line) + folic acid (2x infant’s blood volume is exchanged)
    ± IVIG (for those with haemolytic disease)

Serum bilirubin should be measured EVERY 6 hours until it drops below the treatment threshold or becomes stable/ falling

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

What features necessitate urgent admission/referral for jaundice

A

Emergency: Jaundice + encephalopathy signs e.g. atypical sleepiness, poor feeding, vomiting, hypotonia, hypertonia

Urgent:
- <24h since birth or > 7 days of age
- Unwell e.g. lethargy, fever, vomiting
- Gestational age <35 weeks
- Prolonged jaundice
- Feeding problems/concerns about weight
- Pale stools and dark urine

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

What are the complications of jaundice in neonates

A

Neonatal jaundice

Kernicterus: Deposition of unconjugated bilirubin in the basal ganglia → lethargy, irritability, poor suck, abnormal muscle tone and posture (opisthotonus), high-pitched cry, apnoea, seizures, and coma
→ choreoathetoid cerebral palsy, learning difficulties, sensorineural deafness

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

What is kernicterus

A

Encephalopathy that occurs when the level of unconjugated bilirubin exceeds the albumin-binding capacity of bilirubin of the blood
The free bilirubin is fat-soluble, so can cross the blood-brain barrier → basal ganglia and brainstem nuclei impacted
The neurotoxic effects vary in severity from transient disturbance to severe damage and death

17
Q

What is the prognosis for jaundice in infancy

A

For most babies, jaundice is not an indication of an underlying disease and physiological jaundice is generally harmless and resolves by 2 weeks of age
Breastmilk jaundice, in a baby who is otherwise well, is benign and self-limiting
For babies who require treatment for jaundice, phototherapy prevents bilirubin toxicity
Neurological complications in neonates are rare (0.9 in 100,000 live births)

18
Q

What features suggest kernicterus

A

Serum bilirubin > 340mmol/L in babies > 37 weeks
Rapidly rising bilirubin of > 8.5mmol/L per hour
Clinical features of acute bilirubin encephalopathy
Presents as lethargy and poor feeding ± irritability, increased muscle tone causing them to lie with an arched back (opisthotonos), seizure, coma

19
Q

What is the treatment for kernicterus

A

Immediate exchange transfusion
Phototherapy
Hydration
IVIg

20
Q

What is the management for breast milk jaundice

A

Temporary cessation of breast feeding and supplemental feeding
Phototherapy and hydration
Exchange transfusion if needed