Neonatal Jaundice Flashcards
What causes jaundice?
Abnormally high levels of bilirubin in the blood
Their can be increased production of bilirubin or decreased clearance
Where does bilirubin come from?
Red blood cells contain unconjugated bilirubin
When red blood cells break down, they release unconjugated bilirubin into the blood
Unconjugated bilirubin is conjugated in the liver and either reabsorbed with bile or excreted
Why do neonates get jaundiced?
Fetal red blood cells break down more rapidly
Normally this bilirubin is excreted via the placenta
Liver function is also less developed
Causes of neonatal jaundice - Increased production: (8)
Haemolytic disease of the newborn
ABO incompatibility
Haemorrhage
Intraventricular haemorrhage
Cephalo-haematoma
Polycythaemia
Sepsis and disseminated intravascular coagulation
G6PD deficiency
Causes of neonatal jaundice -Decreased clearance (6)
Prematurity
Breast milk
jaundice
Neonatal cholestasis
Extrahepatic biliary atresia
Endocrine disorders (hypothyroid and hypopituitary)
Gilbert syndrome
When does jaundice happen in a neonate?
Normal between days 2-7 days
Usually resolves by day 10
Prolonged > 14days in full term babies
Prolonged > 21 in prematurer babies
Pathological in the first 24 hours - often caused by neonatal sepsis
Why do premature babies suffer from jaundice?
Physiological jaundice is exaggerated due to the immature liver
Increases risk of complications - kernicterus
Why are babies that are breast fed more likely to have jaundice/
Components of breast milk inhibit the ability of the liver to process the bilirubin
Breastfed babies are more likely to become dehydrated if not feeding adequately
Inadequate breastfeeding may lead to slow passage of stools, increasing absorption of bilirubin in the intestines
What is haemolytic disease of the newborn?
Caused by incompatibility between the rhesus antigens on the surface of the red blood cells of the mother and fetus
What investigations are done in prolonged jaundice? (7)
Full blood count and blood film for polycythaemia or anaemia
Conjugated bilirubin: elevated levels indicate a hepatobiliary cause
Blood type testing of mother and baby for ABO or rhesus incompatibility
Direct Coombs Test (direct antiglobulin test) for haemolysis
Thyroid function, particularly for hypothyroid
Blood and urine cultures if infection is suspected. Suspected sepsis needs treatment with antibiotics
Glucose-6-phosphate-dehydrogenase (G6PD) levels for G6PD deficiency
How is jaundice managed?
Phototherapy
Exchange transfusion
Bilirubin levels plotted on treatment threshold charts
Specific for the gestational age of the baby at birth
How does phototherapy treat jaundice?
Converts unconjugated bilirubin into isomers that can be excreted in the bile and urine without requiring conjugation in the liver
