Work-up of Neonatal Jaundice

                                               Phototherapy,     Cool ! Isn't it ?!

   http://used-medicalequipmentblog.blogspot.com/2012/02/how-neonatal-phototherapy-for-babies.html

Neonatal Jaundice is a very common condition that you would see if you are a pediatrics resident , my approach to this topic would be on how you would think in a case with neonatal jaundice , but first you should have a good platform of knowledge regarding each cause by its own and understand its pathophysiology, so a quick reminder of its causes would be

  A- Physiological

  B- Pathological causes which may be :

    i- Conjugated hyperbilirubinemia:

       1- Sepsis (Neonatal/Infections-UTI)
       2- TORCH
       3- Total Parenteral Nutrition (TPN)
       4- Choledochal cyst 
       5- Galactossemia
       6- Tyrosinemia
       7- Hypothyroidism

   ii- Unconjugated Hyperbilirubinemia

 +ve  Coomb's test:

    1- ABO blood Incompatibility
    2- Thalassemia Minor

 -ve  Coomb's test:

   High Hb value :
    Polycythemia and its related conditions like Infant of a diabetic mother, twin-twin transfusion. Materanl fetal transfusion- intrauterine hypoxia/Intrauterine growth retardation
    also consider delayed separation of the umbilical cord

    Low Hb value :
  then consider intrinsic RBC's wall or enzyme defects like Hereditary Elliptocytosis- Spherocytosis
Glucose-6-phosphate Dehydrogenase Enzyme Deficiency and Pyruvate kinase enzyme deficiency

So suppose you are a resident and got a case with a Neonatal Jaundice , how to organize your thinking ?

1st question that should pop out into your mind would be , Is it Physiological or Pathological ?
 generally speaking, a jaundice that develops in the first day of life or  PERSISTENT hyperbilirubinemia through the second week of life, should always make you suspect a pathological cause, physiological jaundice develops later after birth but never in Day 1 and self limited

also the following signs are highly suggestive of pathological jaundice :

1- total bilirubin levels that exceeds 12mg/dl and direct bilirubin levels that exceeds 2mg/dl in a FULL TERM infant
 
2- a Rapid rise of bilirubin levels by a rate of 5mg/dl/day

Suppose you find a Neonatal jaundice in the first day of life how should you manage ?

1st you would consider Acute and life threatening causes of Neonatal Jaundice , so you would have to exclude Sepsis or intravascular hemolysis, that doesn't mean that other causes wouldn't be investigated or managed but at this stage a severe hyperbilirubinemia in day 1 could be life threatining and unconjugated hyperbilirubinemia may carry complications that you would look forwards to preventing so I believe first you would do the following :

 Liver functions
 CBC/ Blood smear - ESR- Blood Culture- Urine Analysis/Culture
 Reticulocytic count - Coomb's test- ABO blood group testing for both mother and neonate,

consider management of Jaundice with Phototherapy and Exchange transfusion, 

Unconjugated hyperbilirubinemia would result in bilirubin deposition in basal ganglia and brain stem with complications including delayed motor development,hypotonia, opsithotonous, chorio-athetosis, sensorineuronal hearing loss and consequent delayed/absent speech.

later on, after you already ensured the above, you would start screening for other causes through TORCH screening tests, screening for reducing substances in urine, congenital cataracts, Galactose-1-phosphate Uridyl transferase enzyme essay for galactossemia, succinylacetones in Urine for Tyrosinemia, Abdominal Ultrasonography and liver biopsy, assesment for Intrinsic RBC membrane/Enzymes defects.