Neonatal Jaundice Flashcards
What is haemolysis and what are the products?
- Breakdown of RBC
- Produces unconjugated bilirubin (haem), globin and iron
What do babies have an abundance of at birth?
RBC
How does unconjugated bilirubin travel around the body?
Binds to albumin but some is free and able to enter the brain
How does unconjugated bilirubin affect the body?
It is fat soluble so travels to areas of fat in the body and stains them (skin, eyes, gums, roof of mouth)
What happens to unconjugated bilirubin when it reaches the liver?
It is metabolised in the liver to produce conjugated bilirubin which then passes into the gut and is converted to urobilinogen and excreted in urine and faeces
What is SBR?
Serum bilirubin - amount of bilirubin in the blood
What is physiological jaundice and when does it occur?
Slightly raised SBR at day 3-5
Give the word formula for the process of unconjugated bilirubin breaking down
Unconjugated bilirubin -> Glucose + Glucaronic acid + Bilirubin -> (enzyme Gluceronyl transferase) = Conjugated bilirubin -> Urobilinogen
What is the main property of conjugated bilirubin?
Water soluble
What is the definition of Jaundice according to NICE (2015)?
Jaundice refers to the yellow colouration of the skin and the sclerae (whites of the eyes) caused by the accumulation of bilirubin in the skin and mucous membranes
What is another name for Jaundice?
Hyperbilirubinaemia
How many babies develop Jaundice in the first week of life?
Term = 60% Preterm = 80%
Are bottle or breast fed babies more likely to develop physiological Jaundice?
Breastfed
What is prolonged Jaundice?
- Jaundice persisting beyond 14 days (term) or 21 days (preterm)
- Generally harmless but can be an indication of severe liver disease
What is clinical Jaundice?
Jaundice that is visually detectable
What is significant Hyperbilirubinaemia?
An elevation of the SBR to a level requiring treatment
Which types of Jaundice require investigation/ treatment?
- Pathological Jaundice
- SBR continues to rise rapidly between days 3 and 4
- Prolonged Jaundice
- Has abnormally high SBR
- Baby shows signs of being unwell
What is pathological Jaundice?
Jaundice before 24 hours old
- Usually caused by blood incompatibility
- SBR rises very rapidly
- Paediatric emergency - NICE say baby should be admitted to neonatal unit within 2 hours
What causes Jaundice?
- Increased haemolysis of RBC
- Prematurity
- Decreased albumin binding capacity
- Competition for albumin binding sites
- Lack of/ reduction in enzymes and carrier proteins
- Lack of oxygen and glucose
- Hepatitis/ liver damage
- Congenital biliary atresia
How does increased haemolysis of RBC cause pathological Jaundice?
- Rh isoimmunisation or ABO incompatibility
- Congenital spherocytosis/ red cell abnormalities
- Sepsis
- Bruising/ Cephalohaematoma
- Polycythemia
What is Congenital Spherocytosis?
Shortage of RBC
What is Polycythemia?
Increased haematocrit
- Twin to twin/ materno-foetal transfusion
- SFD infants
- Infants of diabetic mothers
What is haematocrit?
The ratio of Volume of RBC: Volume of blood
How does prematurity cause pathological Jaundice?
- Immaturity of the liver
- Low energy stores
- Poor feeding
- Lower levels of SBR will cause brain damage in preterm babies
What are the risks of decreased albumin binding capacity?
- Hypoxia and acidosis
- Infection
- Prematurity
- Hypoglycaemia
What competes for albumin binding sites?
- Free fatty acids (starvation and cold stress)
- Drugs (sulphonamides, cephalosporins, diazepam IV, frusemide, heparin)
What might cause a reduction of enzymes or carrier proteins?
- Congenital disorders
- Prematurity
What may cause a lack of oxygen and glucose?
- Prolonged stress in utero
- Stress in SFD infants
- Hypoxia at birth
What may cause liver damage?
- Metabolic disorders (e.g. galactosaemia)
- Infection
What is congenital Biliary Atresia?
- Rare disorder where part of the liver that drains into the bile duct is abnormally formed
- Early surgery can prevent liver damage so early detection is vital
- Late diganosis = baby could die without a liver transplant
What are some causes of slow bowel motility?
- Poor feeding
- Pyloric stenosis/ bowel obstruction
- Congenital hypothyroidism
What is a meconium plug?
- Takes longer to come out
- Harder, like an actual stool
- Often mixed with mucous
- Inform Paed immediately
What are the dangers of pathological Jaundice?
- Bilirubin levels are generally higher than in physiological Jaundice
- Levels remain high for longer
- Much higher risk of Kernicterus
- Causes may be harmful to the baby
What is the urgent care for a baby with pathological Jaundice?
- Measure and record the SBR level urgently (within 2 hrs)
- Continue to measure SBR every 6 hrs until the level is below the treatment threshold
What is ABO incompatibility?
Mother = Type O
Baby = Type A or B
If sensitising event occurs, anti-A/B antibodies are produced
Affects 2nd pregnancy and can cause Jaundice
Which is more severe; Rh isoimmunisation or ABO incompatibility?
Rh isoimmunisation
Describe Jaundice that is caused by infection
- SBR tends to rise steadily
- Starts to rise related to the time of infection
- If intrauterine infection, may appear in 48 hrs
What should be done for a baby with prolonged Jaundice?
Split bilirubin test
If conjugated bilirubin >20% or total bilirubin >200mmol/l, refer to paed
What are the dangers of jaundice?
- Unconjugated bilirubin can penetrate the membrane that lies between the brain and the blood (blood-brain barrier)
- Unconjugated bilirubin is potentially toxic to neural tissue (brain and spinal cord) and can cause short and long term neurological dysfunction
What is Kernicterus?
The clinical features of acute/chronic bilirubin encephalopathy and the yellow staining of the brain which is associated with this
What is Bilirubin Encephalopathy?
Brain disease/infection caused by high bilirubin levels
How does Kernicterus present in the newborn?
Progressive development of lethargy, rigidity, high pitched cry and convulsions over 24 hrs
What information should be given to parents when they leave the hospital?
- What factors might influence the development of Jaundice
- How to check their baby for Jaundice
- What they should do
- The importance of seeking urgent help if it occurs before 24 hours
What excretory signs could there be that a baby is Jaundiced according to NICE (2015)?
- Pale, chalky stools
- Dark urine
What should be used to measure bilirubin levels?
Transcutaneous Bilirubinometer (baby must be >35/40 and over 24 hrs old)
What should be done if the bilirubin measurement is >250mmol/l?
Measure serum bilirubin (blood test)
In what situation should serum bilirubin be measured straight away?
- Pathological Jaundice
- Born <35/40
- Babies that are at/above relevant treatment threshold
Why is adequate feeding important?
- Breast milk speeds passage of meconium, increasing conversion in bowel to conjugated bilirubin
- Energy for liver function
- Fluid for baby under phototherapy
Why should supplementary fluid be avoided?
This could reduce the intake of breast milk
What information should be given to parents with babies requiring treatment?
- Anticipated duration of treatment
- Reassurance that BF, nappy-changing and cuddles can usually continue
- Lactation/feeding support
What are perspex covers used for?
- Protect from skin irritation and assist thermoregulation
- Do not reduce effectiveness of phototherapy
- Used for term babies only
How does phototherapy work?
Changes bilirubin under the skin from its unconjugated form to non-toxic bilirubin products that can be excreted without conjugation by the liver
When does phototherapy work most effectively?
In the first 48 hours of use
What are the advantages of biliblankets?
- Remove the need for eye covering
- Less stressful for mother and baby
How should a baby undergoing phototherapy be cared for?
- Frequent observations
- Regular feeding
- Protect eyes
- Nurse baby naked (skin to skin)
- Temperature control
What is intensified phototherapy?
- Can be intensified by using another light source of increasing light intensity
- Do not interrupt phototherapy for feeds (use enteral feeds/ IV
- Encourage EBM so BF can resume after treatment
What is conventional phototherapy?
Phototherapy given using a single light source that is positioned above the baby
What is fibreoptic phototherapy?
Phototherapy given using a single light source that comprises a light generator, a fibreoptic cable through which the light is carried and a flexible light pad on which the baby is placed or that is wrapped around the baby
What is multiple/ intensified phototherapy?
- Phototherapy that is given using more than one light source simultaneously
- 2+ conventional units or a combination of conventional and fibreoptic units
- SBR very high so have 1 light above and 1 at side or 1 light above and 1 biliblanket
What is an exchange transfusion?
- Complete changeover of blood if SBR is too high
- Removes maternal antibodies
- Check SBR 2 hrs after change
- 0.3-0.4% mortality
- 5-10% permanent sequelae
Give 3 permanent sequelae that may result from an exchange transfusion?
- Aortic thrombosis
- Intraventricular haemorrhage
- Pulmonary haemorrhage
