Neonatal Jaundice

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Neonatal Jaundice

• Jaundice is visible in newborn skin when bilirubin > 5 mg/dl
• Progression - CephaloCaudal

Kramer's Rule/Zones :

Zone    Bilirubin
 1 ----- 5 mg/dl
 2 ----- 10
 3 ----- 12
 4 ----- 15
 5 ----- >15

• 1g Hb = 34 mg Bilirubin = 1.34 ml O2

• 1g/dl of Albumin binds 8mg Bilirubin

• The bilirubin gets conjugated in Liver (via UDP Glucuronyl Transferase).

• Unconjugated Unbound bilirubin causes Kernicterus.

 Physiological Jaundice of Newborn 

Reasons :

1. Hematocrit of Newborn is more
2. Life span of fetal RBC = 90days {Adult is 120}
3. Y Ligandin - Low
4. UDP - GT - Low
5. Excretion - Less
6. Enterohepatic circulation More

In Term babies - Peaks on day 3 and normal in 7 days (Peak upto 12 mg/dl)

In Pre-term babies - Peaks on Day 5 , normal in 14 days (Peak upto 15mg/dl)

i.e >15mg/dl is Pathological { Palms and Soles - Yellow (see Kramer zones above) }


 Pathological Jaundice 

1. Jaundice on Day 1

2. If

• Mother Rh - , Child Rh +
• Cord Blood Hb <10 g %
• Corl Blood Bilirubin > 5 mg %
• Direct Coomb's +ve

This is an Indication for Exchange transfusion.

3. if Bilirubin increase rate > 0.5 mg/dl/hr

4. If Jaundice persists

• >7days in term 
• >14days in preterm 

5. Jaundice which require therapy.

Most important cause - Rh incompatibility.

Other causes:

• Minor blood group incompatibility
• ABO incompatibility
• Spherocytosis , Elliptocytosis
• RBC enzyme deficiency - G6PD def , Pyruvate Kinase def.

T/t - 

• Phototherapy
• Exchange transfusion

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 Phototherapy ( 425 - 475 nm ) - Blue White Light

Water insoluble bilirubin ------> Water Soluble -----> Excreted

Mechanism:

1. Structural Isomerization (Bilirubin to Lumirubin) (Irreversible)
2. Photoisomerization
3. Photo-Oxidation

• Child 40 cm away from tube.
• 4 - 6 mg/day fall of bilirubin.

Side effects :

1. Fever , dehydration ( therefore do frequent feeding or increase IV fluids by 20%)
2. Retinal Damage (so cover eyes)
3. Mutations in Gonads (so cover gonads too)
4. Hypocalcemia
5. Diarrhoea (watery) - because of bile pigments in gut.
6. Contraindicated in Conjugated Jaundice (Hepatitis) - else Bronze baby syndrome. 

Persistence / Exaggeration of Physiological Jaundice :

1. Congenital Hypothyroidism
2. IVH , Cephalhematoma
3. Battered baby syndrome
4. Crigler Najjar Type II / partial deficiency of UDP-GT (Needs life long phototherapy)
5. Breast Milk Jaundice

Note : In Crigler Najjar Type I - UDP - GT is absent - so all have kernicterus and die.

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