Jaundice Flashcards
What is sclera referring to?
White layer of eye that covers most of the eyeball.
What features are common in jaundice?
Yellow discolouration of the skin
May include the sclera and mucous membranes
Common and mild typically on the head, face and neck.
Why does physiological jaundice occur?
Physiological jaundice occurs as a result of the normal breakdown of red blood cells which contain fetal haemoglobin (fHb) that is no longer required. After the birth, the neonate’s liver takes over the by product of this breakdown of red blood cells-bilirubin and metabolism and excretion of this byproduct occurs in the babies urine.
How is bilirubin synthesised and metabolised?
In the neonate 75% of the bilirubin is a by-product of haemoglobin
This unconjugated bilirubin is conjugated by enzymes in the neonates liver to become more water soluble to be excreted into the bile or urine (via the kidneys)
What enzyme conjugates bilirubin in the liver to make it more water soluble for excretion?
Bilirubin is conjugated within the hepatocyte to glucuronic acid by a family of enzymes, termed uridine-diphosphoglucuronic glucuronosyltransferase (UDPGT).
What two vital ingredients are required for the conjugation of billirubin in the liver to become more water soluble for excretion?
oxygen and glucose
What two abnormal events can slow down the conjugation of billirubin and why?
Hypoxia- oxygen required for conjugation
Hypoglycaemia- glucose required for conjugation
What type of newborn gets physiological jaundice and when?
All neonates have a peak of unconjugated bilirubin on the third or fourth day of life which can cause physiological jaundice.
What enzyme deficiency on day 3-4 postnatally causes a reduced excretion of conjugated bilirubin?
glucuronyl transferase enzyme (GTE)
What is most common type of Jaundice? (Physiological, Breast Milk Jaundice, Pathological)
Most common physiological (60% full term, 80% preterm)
What is prehepatic jaundice?
caused by conditions that heighten your blood’s rate of hemolysis- Because the liver can only process so much bilirubin at once, bilirubin overflows into bodily tissues
What is Pathological jaundice?
Arises from factors that alter neonates usual processes
Can be mixed unconjugated and conjugated bilirubin
Hepatic or post hepatic (relating to the liver)
What is Breast Milk jaundice?
Hepatocellular (relating to or involving liver cells)
Unconjugated bilirubin
Why does Breast Milk Jaundice occur?
Breast milk jaundice most often occurs in the second or later weeks of life and can continue for several weeks. While the exact mechanism leading to breast milk jaundice is unknown, it is believed that substances in the mother’s milk inhibit the ability of the infant’s liver to process bilirubin.
What liver cells conjugate bilirubin?
Hepatocytes
What is water soluble bilirubin called?
Conjugated Bilirubin
Haemolysis is increased in neonates more than adults. True or False?
True
Why is Haemolysis increased in newborns vs adults? 2 reasons
Polycythemia (more RBC than adults)
FoetalHb makes RBCs more fragile – shorter life span (80-100 d vs 120 d)
What is Kernicterus?
a rare but serious complication of untreated jaundice in babies. It’s caused by excess bilirubin damaging the brain or central nervous system.
What type of Bilirubin can cause Kernicterus?
Unconjugated bilirubin can pass blood-brain-barrier and affect brain