Jaundice Flashcards
Neonatal jaundice
Conjugated
And unconjugated causes
Conjugated increased production of RBC Shorter rbc survival Higher rbc mass/kg Decreased metabolism immature liver in neonate Less hepatitic uptake Immature liver enzymes Enterohepatic circulation Decreased gut motility Sterile gut
HyperBr is defined as
In term infant unconjugated Br >205 mMol/
Preterm infant ** check this level
Conjugated direct >40
Jaundice is common
25-50% term babies
85% preterm babies
Kernicterus is rare and preventable
G6PD def is one of the common causes in Australia ( Asian males can be female less likely)
UnConjugated Jaundice
Increased production of Br from breakdown
Less conjugation
Increased circulation
Causes
Physiological
Hemolytic
Prolonged
Increased production in unconjugated Jaundice causes
Isoimmune hemolysis. ABO incompatibility
Erythrocytes biochem abnormality G6PD def
Abnormal RBC morphology elliptical or spherocytosis
Sequestered blood cephalohaematoma
Polycythemia
Decreased conjugation ( unconjugated Jaundice)
Premature infants
Metabolic (Gilberts/ Crigler Najjar )
Endocrine hypothyroidism / child of DM mother / hypopituitarism growth hormone def hypoglycemia/neonatal jaundice
Increased enterohepatic circulation
Intestinal atresia
Hirschprungs
Meconium ileus
Physiological Jaundice
Appears >24hours ( after day 1 when the baby goes home early)
SBR rise <86mm/l/day ( slow rise)
Peaks day 3-5 NOT >258mm/l
Resolves by 1/52 in term infants and 2/52 in a preterm infant
Early onset BF Jaundice
5-10% of newborn Jaundice
Insuff production or intake of Breast milk
Late onset Breast milk Jaundice
Diagnosis of exclusion
Starts 4-7 days max day 6-14days
Persists beyond physiological Jaundice
May remain raised Br 1-3/12 of age
G6PD def
Enzyme in the RBC
Provides NADPH which is a buffer agains oxidative stress
Commonest cause of RBC enzyme def
Sex linked so MALES effected commonly ( but can seen in Females)
Thought to protect against Malaria
Common in Asian families and napthaline can ppt a crisis
Causes of Conjugated Jaundice
1 Hepatitis
2 Biliary atresia (clay colored stools/dark urine) DISIDA scan
3 biliary obstruction eg cholodocal cyst USS of abdomen
4 Alpha 1 AT def
5 TPN cholestatsis seen in PICU
Approach to prolonged Jaundice
Exclude obstruction biliary atresia or choledocal cyst
Hypothyroidism
Infection Urine
If not breast fed or is high Br Ix further
Kernicterus
Br staining of the neurons and neuronal necrosis affecting the basal ganglia hippocampus and the subthal nucliea
Free unconjugated br crosses the BBB ( if its linked to Albumin too big and cannot cross the BBB)
PPT at low ph and toxic to neurons
Causes cell death
Clinical presentation of Kernicterus
Acute low tone poor suck t
Then get hypertonic fevers and seizures
Then hypotonia
Chronic
Hypotonic Extrapyrmaidal side effects
CP, deaf, effects congnition
Which babies are at risk of Kernicterus
Preterm infants (BBB more permeable)
Low Albumin ( if high Al binds the Br and its too big to cross the BBB)
Rapid rise in Br level
Hypoxia/ Acidisos/Sepsis/Hypoglycemia
Infections such as TRCH toxoplasmosis, rubella, CMV,Herpes
Maternal factors effect Kernicterus
Blood group
DM ( increased risk of polycythemia)
At risk Neonates for Kernicterus
Jaundice within 24hours Previous J in a sibling Gestation 35-38weeks ( younger you are the >risk) Exclusive BF Asian G6PD def ( napthaine balls ) Cehpalheamatoma/bruising Males
Investigations for Jaundice
SBR fractions ( conj/unconjugated)
Haemolysis FBC and film look at RBC morphology
Infections UTI Blood cultures
Metabolic
Treatment of Jaundice
Aim is to prevent Kernicterus
Treatment of Jaundice
Aim is to prevent Kernicterus Phototherapy Albumin Iv immunoglobulin Exchange transfusion
Phototherapy
450-460nm light (blue not ultraviolet light) Indications for it rh disease Other haemolytic disease Small sick infants Safe and effective ( blue light is the most effective) CEASE photo therapy when the SBR falls 25-50 mMol/l below the threshold Monitor for Hypo/hyperthermia Dehydration Eye damage Rashes Diarrhea
When to start phototherapy
There are specific nomograms to assist at the risk for hyperBr and when to use phototherapy based on age and level of Br
IV immunoglobulin
Used with phototherapy to treated Jaundice been shown to reduce the need for exchange transfusion
Been shown to reduce the sr Br level
Albumin
If low sr albumin it has been shown that this binds the Br and reduces the risk of Kernicterus
Exchange transfusion uses
1 ABO or other blood grp incompatibility if Br >340
2 preterm infant /infant of DM mother Br>340
3consider exchange transfusion for
Rh sensation with +ve Coombs test
Oedema/peticha /HSM / rapidly developing Jaundice
Maternal anti Rh titre >/=1:64
Indirect Br >340
Conjugated Br >90
What does exchange transfusion do?
1 removes unconjugated Br Ab coated RBC Ab again RBC antigen 2 provides durable RBC 3 does not remove tissue Br ( not from the skin so need to keep photo therapy going after exchange transfusion can get rebound J)
Kramers rule
Face/head 100 Chest and 1 150 Abdomen and 1/200 Legs 250 Feet and hand >250 Not reliable
Weight loss in a Jaundiced baby
Weight loss in BR babies can be 10% from birth
Median loss 6.6% in a term BF baby
Median loss 3.5% in a term bottle fed baby
Breast fed Jaundice <290
