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Bilirubin Total
Test CodeBILIT
Alias/See Also
Epic: LAB50
Preferred Specimen
Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL
Minimum Volume
0.10 mL
Instructions
- Centrifuge and separate cells after clot formation and within 4 hours of collection.
- Protect specimen from bright light.
Transport Container
Plastic vial
Specimen Stability
Room temperature: 24 hours
Refrigerated: 7 days
Frozen: 6 months
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Unlabeled, mislabeled, wrong tube type, QNS, hemolyzed, or lipemic.
Methodology
Diazonium Salt
Setup Schedule
Daily
Report Available
Same day
Reference Range
| 0-1 day | 1.0-6.0 mg/dL |
| >1-2 days | 6.0-8.0 mg/dL |
| >2-5 days | 4.0-12.0 mg/dL |
| >5-10 days | 0.2-2.0 mg/dL |
| >10 days-150 years | 0.2-1.2 mg/dL |
Clinical Significance
RBC's at the end of their circulating lives are broken down in the reticuloendthelial system, mainly in the spleen. The resulting heme is converted to bilirubin upon removal of iron. This process accounts for about 80% of the total formed daily. Other sources include the breakdown of myoglobin and cytochromes and the catabolism of immature RBC's in the bone marrow.
Bilirubin is transported to the liver bound to albumin. This fraction is referred to as indirect (unconjugated) bilirubin. In the liver, bilirubin is conjugated to glucuronic acid to form direct (conjugated) bilirubin and is excreted via the biliary system into the intestine where it is metabolized by bacteria. Elimination is almost complete and serum levels are normally negligible.
Total Bilirubin is the sum of the direct and indirect fractions. Total bilirubin is elevated in hepatitis, cirrhosis, hemolytic disorders, several inherited enzyme deficiencies, and conditions causing hepatic obstruction.
Neonatal bilirubin quantification is used to monitor diseases causing jaundice in the newborn, chiefly hemolytic disease of the newborn (HDN).
The average full-term newborn infant has a peak serum bilirubin concentration of 5-6 mg/dL. Physiologic jaundice is seen at serum bilirubin concentrations from 7-17 mg/dL. Serum bilirubin concentrations greater than 17 mg/dL may be pathologic. The primary concern is the potential for bilirubin encephalopathy or kernicterus.
Bilirubin is transported to the liver bound to albumin. This fraction is referred to as indirect (unconjugated) bilirubin. In the liver, bilirubin is conjugated to glucuronic acid to form direct (conjugated) bilirubin and is excreted via the biliary system into the intestine where it is metabolized by bacteria. Elimination is almost complete and serum levels are normally negligible.
Total Bilirubin is the sum of the direct and indirect fractions. Total bilirubin is elevated in hepatitis, cirrhosis, hemolytic disorders, several inherited enzyme deficiencies, and conditions causing hepatic obstruction.
Neonatal bilirubin quantification is used to monitor diseases causing jaundice in the newborn, chiefly hemolytic disease of the newborn (HDN).
The average full-term newborn infant has a peak serum bilirubin concentration of 5-6 mg/dL. Physiologic jaundice is seen at serum bilirubin concentrations from 7-17 mg/dL. Serum bilirubin concentrations greater than 17 mg/dL may be pathologic. The primary concern is the potential for bilirubin encephalopathy or kernicterus.
Performing Laboratory
Inova Laboratories
2832 Juniper Street
Fairfax, VA 22031
Additional Information
ILS Total Bilirubin Abbott AlinityJob Aid
Last Updated: April 11, 2023
Last Review: N. Wolford, March 6, 2023