Neonatal Jaundice: Physiological and Pathological Jaundice

Neonatal jaundice is a yellow discoloration of the skin and mucous membranes as a result of raised bilirubin levels occurring in the first 28 days of life.

The term Jaundice comes from the French word jaundice, which means yellow; thus a jaundiced baby is one whose skin color appears yellow due to bilirubin.

Bilirubin level of more than 85 umol/l (5 mg/dL) manifests clinical jaundice in neonates whereas in adults a level of 34 umol/l (2 mg/dL) would look icteric.

Predisposing factors of Neonatal Jaundice

A newborn baby has a hemoglobin (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 fetal RBCs may cause bilirubin to exceed the plasma carrying capacity of the blood. Therefore causing Physiological jaundice.

What is bilirubin??

Bilirubin is a product of hemoglobin breakdown. Hemoglobin is contained in the red blood cells and its most important function is to carry oxygen to the tissues. When a red blood cell reaches the end of its life, the reticuloendothelial system takes it out of circulation. This consists of the liver and spleen.

The hemoglobin is broken down into its two constituents: Haem and Globin.

The globin is a protein that 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.

Bilirubin is a product of this last process and the accumulation in the blood causes yellow staining on the skin.

Bilirubin toxicity

Bilirubin can cross the blood/brain barrier and stain the basal ganglia, hippocampus, cranial nerve nuclei, cerebellar nuclei, and inferior olivary nuclei. This staining is permanent,  which is why high serum bilirubin levels are so dangerous.

Original yellow deposits fade leaving dead neurons resulting in permanent brain injury.

Types of Neonatal Jaundice

1. Physiological Jaundice
2. Pathological Jaundice

Physiological jaundice

Physiological jaundice 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.

This type of jaundice is the consequence of immature liver enzymes and high red cell mass.
Other Factors which may increase Physiological Jaundice
• Prematurity
• Bruising
• Polycythemia
• Breastfeeding

Pathological jaundice

Pathological jaundice refers to jaundice that arises from factors that alter the usual process involved in bilirubin metabolism in the liver. It is significant in the first 24 hours of life especially if there is Rhesus incompatibility.

It may persist for more than 2 weeks in some conditions when the baby will be jaundice all over and may appear a muddy yellow color.

These conditions include:-

• Group incompatibility (Haemolytic Disease of the Newborn) Rhesus factor, ABO incompatibility
• Hypoxemia
• Sepsis
• Endocrine or metabolic disorders and bile duct obstruction
• Hypoglycemia

Causes of neonatal jaundice according to the age of onset


Important history: Age of onset and duration, the color of stool, previous sibling with neonatal jaundice

Assessment of jaundice

Assess for the severity of jaundice (Kramer's staging) and signs of bilirubin encephalopathy (bilirubin induced neurological dysfunction [BIND])

Bilirubin levels (Kramer's staging)

Any jaundice = 90umol/L

Head and neck = 70-130umol/L

Trunk, to elbows and knees = 190-300umol/L

Hands and feet > 300umol/L

Clinical bilirubin-induced neurological dysfunction on BIND score

Interpretation of the scores

Scores 1–3 = subtle signs of acute bilirubin encephalopathy
Scores 4–6 = moderate acute bilirubin encephalopathy reversible with urgent and prompt treatment (exchange transfusion)
Scores 7–9 = advanced acute bilirubin encephalopathy; urgent, prompt, and individualized intervention are recommended to prevent further brain damage. (exchange transfusion) .

Investigations and Management of neonatal Jaundice

The aim of the management of neonatal Jaundice is:-

To prevent bilirubin encephalopathy (kernicterus) developing as a result of high levels of serum bilirubin.

Treatment of underlying conditions.

Maintenance of hydration and nutrition.

Treat the cause if treatable

Start investigations if:-

• Jaundice is significant in the first 24 hours
• 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 mother's blood group for compatibility and rhesus antibody status.

Coombs's 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 hemolysis causing anemia

Check baby for Infection

If the baby’s SBR is above the treatment line (depending on which charts your unit uses) Phototherapy can commence.

For physiological jaundice, occurring after 48 hours of birth and resolves 7-10 days or a little longer in the preterm, the baby looks and feeds well. You only need to counsel the mother to continue with breastfeeding and review after 3 days if jaundice deepens or the development of danger signs.

Phototherapy

The goal of phototherapy is to avoid concentrations that may result in kernicterus.

Its effectiveness is related to the area exposed, radiant energy, and wavelength 400-500 nanometers.

Phototherapy is administered according to age, gestation/weight, and severity of jaundice.

Blue light range Acts on unconjugated bilirubin converts it to biliverdin (more soluble and readily excreted in bile)

Indications of phototherapy

Phototherapy is indicated in:

  • Jaundice within 24hrs
  • Deep jaundice involving palms and soles
  • Prematurity and jaundice
  • Jaundice due to hemolysis
  • Phototherapy checklist

  • 1. Shield the eyes with eye patches - Remove periodically such as during feeds. Check for eye discharge
    2. Keep the baby naked but ensure the neutral thermal environment
    3. Place the baby close to the light source 30- 45 cm distance the closer the better provided the baby is not overheating especially if the rapid effect is needed.
    4. Promote frequent breastfeeding. Give IV fluids if not able to feed. Unless dehydrated, supplements or intravenous fluids are unnecessary. Phototherapy use can be interrupted for feeds; allow maternal bonding.
    5. Periodically change position supine to prone - Expose the maximum surface area of the baby to phototherapy; reposition after each feed.
    6. Monitor
      a. Temperature every 3 hrs
      b. Vital signs 3hrly
      c. Hydration status (Capillary refill time) 3hrly and weight every 24 hrs.
      d. Feeding/fluid intake 6hrly(Input/output)
      e. Pallor
    7. Periodic (12 to 24 hrs) plasma/serum bilirubin test.
    Visual testing for jaundice or transcutaneous bilirubin is unreliable. If rising /no response to phototherapy consider exchange transfusion
    8. Monitor for signs of bilirubin encephalopathy - if it is present, then plan for exchange transfusion
    9. Cover lipid lines with light-resistant, reflective tape to avoid peroxidation.
    10. Make sure that each light source is working and emitting light. Fluorescent tube lights should be replaced if:
    a. More than 6 months in use (or usage time >2000 hrs)
    b. Tube ends have blackened
    c. Lights flicker
    d. According to the manufacturer's specifications

  • Jaundice treatment if the baby is <37 weeks gestation


What are the adverse effects of Phototherapy?

  • Dehydration
  • Increased insensible water loss
  • loose stools
  • Irritability or lethargy
  • Skin rashes
  • Overheating
  • Retinal injury
  • Adverse effect on cell growth
  • Oxidize essential fatty acids, decreases vitamins and calcium in premature infants
  • Tanning/Bronze Baby Syndrome with conjugated hyperbilirubinemia

You may need to increase the baby’s fluid

Indomethacin dislodges Bilirubin from its plasma binding site so it increases SBR levels.

You may require I.V. access.

You may need to pass an Ng/Og tube.

Once Phototherapy has commenced you need to take an SBR at regular intervals the frequency depending on how high it is.

If the therapy that is being given isn’t reducing the SBR you may need to consider an Exchange Transfusion.

The decision to exchange transfuse is not just determined by the level but by the rate at which the increase, which is why it is so important to plot SBR result on a time/SBR level graph.

Consider at serum unconjugated bilirubin concentrations of 400-430 umol/L
Exchange transfusion involves slow removal of aliquots (10mls) from an artery and simultaneous injection into a vein 2. Serial withdrawal and injection of aliquots (5-20 ml) through the umbilical vein.

Therefore after a few days of treatment, jaundice will subside and the treatment can be discontinued.

Phenobarbital Accelerates metabolic pathways for bilirubin clearance
Tin-mesoporphyrin inhibits heme oxygenase
IV gamma globulin inhibits hemolysis
Activated Charcoal binds bilirubin in the intestine

author

Daniel Ogera

Medical educator, passionale about pharmacology, physiology and pathophysiology.

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