Jaundice

Definition = Neonatal jaundice is the term used when a newborn has an excessive amount of bilirubin in the blood. Bilirubin is a yellowish-red pigment that is formed and released into the bloodstream when red blood cells are broken down. Jaundice comes from the French word jaune, which means yellow; thus a jaundiced baby is one whose skin colour appears yellow due to bilirubin.

Predisposing causes of Jaundice:
• A newborn baby has a haemoglobin (Hb) level of 18-19g/dl. This is necessary during fetal life to facilitate oxygen carrying capacity.
• As soon as the baby is born and able to breathe oxygen the high Hb level is not needed and starts to drop.
• In the first week of life the baby’s Hb will drop to about 11g/dl and this breakdown of the foetal RBC’s may cause bilirubin to exceed the plasma carrying capacity of the blood.
• Therefore causing Physiological JAUNDICE

What is BILIRUBEN?
• Bilirubin is a product of haemoglobin break-down. Haemoglobin is contained in the red blood cells and it’s most important function is to carry oxygen to the tissues.
• When a red blood cell reaches the end of it’s life, the reticuloendothial system takes it out of circulation.
• This consists of the liver and spleen.
• The haemoglobin is broken down into it’s two constituents: Haem and Globin. • The globin is a protein which is re-used by the body.
• The Haem is an iron compound and so can’t be re-used. It is broken down to be excreted.
• Biliruben is a product of this last process and the accumulation in the blood causes yellow staining on the skin: JAUNDICE.
• Biliruben can cross the blood/brain barrier and stain the basal ganglia. The staining is permanent, Damage irreversible, which is why high SBR is so dangerous

Types of Jaundice
• Physiological Jaundice
• Pathological Jaundice

Types of Jaundice Physiological
• This occurs in the first few days after birth and will have cleared by day 10
• It occurs because of physiological changes taking place during the transition from intrauterine to neonatal life
• It is the consequence of: immature liver enzymes, high red cell mass

Other Factors which may increase Physiological Jaundice
• Prematurity
• Bruising
• Polycythemia
• Breast feeding

Types of Jaundice Pathological
• This refers to jaundice that arises from factors that alter the usual process involved in biliruben metabolism in the liver
• It is significant in the first 24hrs of life especially if there is Rhesus incompatibility
• It may persist more than 2 weeks in some conditions when the baby will be jaundice all over and may appear a muddy yellow colour

Pathological Jaundice
• This includes :-
• Group incompatibility (Haemolytic Disease of the Newborn) Rhesus factor, ABO incompatibility
• Hypoxemia
• Sepsis
• Endocrine or metabolic disorders and bile duct obstruction
• hypoglycaemia

Management of Jaundice
• The aim of the management of Jaundice is to prevent biliruben encephalopathy (kinicterus) developing as a result of high levels of serum biliruben.
Start investigations if:-
• Jaundice is significant in the first 24hrs
 • Jaundice persists after 10 days
• If the SBR is above 250umol/l or less in preterm babies
• If Jaundice is present in a baby who is already ill
• Ascertain mothers blood group for compatibility and rhesus antibody status. Coombes antibody status should be obtained from mothers notes.
• Check baby’s blood group for Rhesus status, and Hb in case the jaundice is caused by haemolysis causing anaemia
• Check baby for Infection
• If the baby’s SBR is above the treatment line (depending on which charts your unit uses) Photo therapy can commence.
• You may need to increase the baby’s fluid depending on you units policy. (you need to be familiar with unit policy)
• Indomethacin dislodges Biliruben from it’s plasma binding site so increases SBR