neonatal jaundice Flashcards
what is jaundice
yellowing of the skin and sclera
what causes jaundice physiologically
due to high levels of bilirubin in blood
is the pathological or physiological in new borns
mainly physiological
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what is gliberts disease
certain enzyme abnormalities which affects conjugation
mutation of UGT1A1 gene - reduces bilirubin uridine diphosphate glucuronosyltransferase by around30% (bilirubin-UGT) and can make jaundice worse
what can bilirubin crossing the BBB cause
encephalopthay which can lead to kernicterus
what is there a small risk of with high levels of bilirubin
cerebral palsy
what hours of birth is jaundice become pathological?
if still occuring late >14 weeks in term and 21 days in preterm
due to haemolysis, sepsis, metabolic disorders, liver disease
why does physiological jaundice develop?
increased productino; foetal RBC life span 2/3 of adults, high hct, brusing
decreased uptake and binding by liver cells
decreased conjugation
decreased excretion
increased enterohepatic circulation of bilirubin
to early jaundice is almost always pathological, what is this due to?
haemolysis, with excessive production of bilirubin, sepsis could be an underlying cause
when can babies be born with jaundice
severe haemolysis
hepatits
causes of haemolysis
ABO incompatibility
Rh immunisation
sepsis
how do you investigate early pathological jaundice?
total bilirubin conc (SBR)
maternal blood group and antibody titres (if Rh neg)
baby blood group, direct agglutination test, elution test to detect antiA or antiB antibodies on babys red cells
FBC - evidence of haemolysis
CRP - infection?
haemolysis investigations
blood group incompatibility (commonly with rhesus or ABO) identified with a positive direct agglutination test (DAT)or due to a glucose 6 phosphate dehydrogenase deficiency
haemolysis investigations
blood group incompatibility (commonly with rhesus or ABO) identified with a positive direct agglutination test (DAT)or due to a glucose 6 phosphate dehydrogenase deficiency
features of bilirubin encephalopathy
lethargy poor feeding temp instability hypotonia arching of the head, neck, and back spasticity seizure
causes of SBR being too high
mild dehydration/insufficient milk supply breakdown of extravasated blood haemolysis infection increased enterohepatic circulation
causes of SBR being too high
mild dehydration/insufficient milk supply breakdown of extravasated blood haemolysis infection increased enterohepatic circulation
causes of persistent unconjugated hyperbilirubinaemia
breast milk jaundice poor milk intake haemolysis infection hypothyroidism
causes of persistent conjugated hyperbilirubinaemia
hepatitis - infection or metabolic disorders
biliary atresia - pale stools dark urine, surgery with a kasai portoenterostomy before 3 months of age
causes of persistent unconjugated hyperbilirubinaemia
hypothyroidism - persistent jaundice is the earliest sign
breast milk jaundice - normal conjugated portion, normal FBC and blood group to exclude haemolysis, no sign of infection UTI, thriving, reassurance
treatment of jaundice
treat cause
adequate feeding
enteral feeding is best in order to reduce enterohepatic circulation of bilirubin
PHOTOTHERAPY - bluelight
exchange transfusion for haemolytic disease
IV IMMUNOGLOBULIN with imfants with isoimmune haemolytic disease and rising bilirubin despite intensive phototherapy
onset day 1, peak variable, prolonged after day 14
symptoms and signs of aetiological cause eg lethargy for sepsis; pale stool for hepatitis
likely pathological
onset day 2
peak day 5
resolve day 10-14
otherwise well
physiological
