HYPERBILIRUBINEMIA

Fatima C. Dela Cruz

Jaundice

Yellowish discoloration of the skin, sclera and other mucous membranes of the body

Jaundice

Accumulation in skin of unconjugated, non-polar, lipid-soluble bilirubin pigment formed from Hgb by the action of heme oxygenase, biliverdin reductase, & non-enzymatic reducing agents in the reticuloendothelial cells

Deposition of the pigment after it has been converted in the liver cell microsome by the enzyme uridine diphosphoglucuronic acid (UDP)-glucuronyl transferase to the polar, water-soluble ester glucuronide of bilirubin (direct reacting)

Jaundice

Face (total serum bilirubin ~ 5mg/dl) Midabdomen (TSB ~15 mg/dl) Feet (TSB ~20mg/dl)

Jaundice

Dermal Zones of Jaundice (Kramer, 1969)

Zone Range of TSB (mg/dL)

1 4.3 – 7.92 5.4 – 12.23 8.1 – 16.54 11.1 – 18.35 >15

Bilirubin

Macrophages Bloodstream Liver Gut

RBCs Heme Unconjugated Unconjugated bilirubin- Conjugated Urobilinogen

bilirubin albumin complex bilirubin

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Albumin

Indirect Bilirubin Direct bilirubin

Uridine

Glucuronyl transferase

80% -feces20% 10%-urine 90%-liver

Jaundice

Unconjugated hyperbilirubinemia is bright yellow or orange

Direct hyperbilirunemia is greenish or muddy yellow

Differential Diagnoses

Jaundice appearing at birth <24 hours Sepsis Erythroblastosis fetalis Concealed hemorrhage Cytomegalic inclusion disease Rubella Congenital toxoplasmosis

Differential Diagnoses

Jaundice appearing on the 2nd or 3rd day Physiologic hyperbilirubinemia of the

newborn Criggler-Najjar syndrome (familial

nonhemolytic icterus)

Differential Diagnoses

Jaundice appearing after the 3rd day, within the 1st week

Septicemia Syphilis Toxoplasmosis Cytomegalic inclusion disease Other causes of early jaundice

(Intrauterine transfusions, Extensive ecchymosis or hematomas, Polycythemia)

Differential Diagnoses

Jaundice appearing after the 1st week Breast milk jaundice Septicemia Congenital atresia of the bile ducts Hepatitis Rubella Galactosemia, hypothyroidism Spherocytosis (congenital hemolytic

anemia) Other hemolytic anemias (G6PD deficiency,

Glutathione synthetase deficiency, Peroxidase deficiency, Pyruvate kinase deficiency)

Physiologic Jaundice

Result of increased bilirubin production following breakdown of fetal red blood cells and limitation of liver bilirubin conjugation

Indirect bilirubin: 1-3 mg/dL; rises at a rate <5mg/dL/24h

Usually visible by the 2nd-3rd day and disappears by the 5th-7th day

Pathologic Jaundice

Jaundice appears in the first 24-36 h of life

Total serum bilirubin (TSB) rises by > 5 mg/dL/day

Serum bilirubin >12 mg/dL term and 10-14 mg/dL in preterm infants

Jaundice persists after 10-14 days of life Direct-reacting bilirubin >2 mg/dL at any

time

Pathologic Jaundice

1. Hemolytic disease Rh incompatibility ABO incompatibility Drugs (vitamin K) Congenital

hypothyroidism Increased hemolysis Cephal hematoma

2. Hepatocellular injury Biliary atresia Cholestasis Hepatitis Infection

3. Mixed hemolytic and hepatotoxic factors Infection (bacterial

and viral)

4. Hyperbilirubinemia secondary to metabolic factors Hypoxia Respiratory distress Hypoglycemia Hypothyroidism

Breastfeeding Jaundice

bilirubin during the first week of life in breastfed infants due to both caloric and fluid deprivation

Resolves with increased breast feeding frequency and amount of milk intake

Breastmilk Jaundice

Jaundice among breastfed infants probably secondary to hormones (pregnanediol) in milk acting on infant’s hepatic metabolism and an enzyme (glucuronidase) facilitating intestinal reabsorption of bilirubin

Treatment

Phototherapy Exchange transfusion Intravenous immunoglobulin Metalloporphyrins

Treatment

Phototherapy Exposure to a high intensity of light in the visible

spectrum Bilirubin absorbs light maximally in the blue range Photoisomerization

converts unconjugated bilirubin (4Z, 15Z) into unconjugated isomer (4Z, 15E) which is excreted in the bile

Structural change converts unconjugated bilirubin to lumirubin, which is

excreted in the urine in an unconjugated state

Treatment

Exchange transfusion Partial removal of the infant’s circulating

antibody coated RBCs as well as unattached antibodies and replace