03.12 Jaundice in Children Flashcards
Also known as icterus
Yellow discoloration of the skin and sclerae due to excess bilirubin in the blood
Jaundice
Increased levels of conjugated bilirubin
Direct hyperbilirubinemia
Increased levels of unconjugated bilirubin
Indirect hyperbilirubinemia
Primary site of erythropoiesis
Bone marrow
Hemoglobin is then phagocytosed by _____, and is split into globin and heme
Macrophages (RES)
In the third step, heme is converted into ____ through the action of ____
Biliverdin
Heme oxygenase
The formed biliverdin is rapidly reduced to free ___ through the aciton of ____
Bilirubin
Biliverdin reductase
Site of conjugation for bilirubin
Liver
Released bilirubin is conjugated to ____ through the action of ____
Glucoronic acid
Glucoronyltransferase
The conjugated form of bilirubin has the following characteristics
Greenish
Water soluble
Readily excreted
The conjugated bilirubin is then secreted through ____ in the _____
Ampulla of Vater
2nd segment of the duodenum
The conjugated bilirubin is acted upon by bacteria in the ____ , which causes the removal of glucuronic acid through ___, and converting the conjugated bilirubin into ____
Terminal ileum and proximal colon
Hydrolysis
Urobilinogen
Colorless
Water soluble
Urobilinogen
90% of the urobilinogen is further oxidized by bacteria forming ____, which is oxidized to ____ that contributes to the brown color of the feces
Stercobilinogen
Stercobilin
Etiology of direct hyperbilirubinemia
Decreased excretion by the damaged hepatic parenchymal cells
Disease of the biliary tract
Often signifies a serious hepatic or systemic illness
Conjugated direct hyperbilirubinemia
Etiologies of indirect hyperbilirubinemia
Increased load of bilirubin to be metabolized by the liver (hemolytic anemia, polycythemia, shortened red cell life, increased enterohepatic circulation, infection)
Damaged or reduced activity of the transferase enzyme (genetic deficiency, hypoxia, infection, thyroid deficiency)
Factors that competes for or blocks the transferase enzymes (drugs, etc)
Factors that lead to absence or decreased amounts of enzyme or to reduction of bilirubin uptake by the liver cells (genetic defect, prematurity
Also known as icterus neonatorum
Occurs in 60% of term infants and 80% of preterm infants
Physiologic jaundice
Most common reason of bilirubin accumulation in physiologic jaundice is a ______
Breakdown of fetal RBC
Visible manifestations of jaundice in icterus neonatorum appears at the _____ when serum bilirubin levels are _____
2nd-4th day of life
5-6 mg/dL
Under normal circumstances, the level of indirect bilirubin in umbilical cord serum is _____ and rises at a rate of ____
1-3 mg/dL
<5 mg/dL/day
Hyperbilirubinemia (___ mg/dL) in 13% of breastfed infants in the ____ due to _____ with _____ is referred to as ____
12 1st week of life Decreased milk intake Dehydration or reduced caloric intake Breastfeeding jaundice
Mild form of dehydration in 1st week of life due to decreased milk intake
May be due to the shift towards non-exclusive breastfeeding
Breastfeeding jaundice
Hyperbilirubinemia (___ mg/dL) after the ___ in 2% of BF infants is referred to as ____
10-30
7th day of life
Breastmilk jaundice
Some milk has a ____ that causes the breastmilk jaundice
Glucoronidase
Warning signs for pathological jaundice
Appears int he first 24 hours of life
Serum bilirubin rising at a rate faster than 5mg/dL
Serum bilirubin > 12 mg/dL
Jaundice persists after 10-14 days of life
Direct-reacting bilirubin >2 mg/dL
Types of jaundice
Physiologic
Pathologic
Causes of increased direct bilirubin
Sepsis Intrauterine infection (toxoplasmosis, CMV, rubella, herpes, syphilis) Severe hemolytic disease Choledochal cyst Cystic fibrosis Galactosemia Alpha1-antitrypsin deficiency Tyrosinemia
Looks for Abs that may stick to your red blood cells and cause RBCs to die early
Coombs test
Most common cause of indirect hyperbilirubinemia in the infant is _____
Isoimmunization
Production of antibodies against constituents of tissues of another individual of the same species
Isoimmunization
An elevated HgB may indicate ____ due to:
Polycythemia Due to: -twin transfusion -maternal-fetal transfusion -delayed cord clamping -small for gestational age infant
Salient features of neonatal jaundice
Maternal history Birth history Parental blood type Onset Clinical course Interval history Vital signs Organomegaly Maturity Feeding history Nutritional history
Transcutaneous measurements of jaundice in face, mid-abdomen and soles
5 mg/dL
15
20
Jaundice is bright yellow or orange in ___ hyperbilirubinemia, greenish to mud yellow in ___
Indirect
Direct
Complication of hyperbilirubinemia
Bilirubin encephalopathy
Neurologic syndrome resulting from the deposition of unconjugated bilirubin in the basal ganglia and brainstem nuclei
Kernictus
Treatment of hyperbilirubinemia
Phototherapy
Exchange transfusion
Skin absorbs blue light and thorugh photoisomerization converts the toxic ubilirubin into the unconjugated configurational isomer that may be excreted without conjugated
Phototherapy
