Direct Bilirubin
From Health Facts
Latest Edit: Iva Lloyd, ND 2021-08-24 (EDT)
| See Also | Lab Tests |
|---|
Direct bilirubin refers to the inidrect or unconjugated bilirubin that has been conjugated with a number of different molecules and then excreted in the bile. Increased direct or conjugated bilirubin is usually inidcative of a dysfunction or blockage in the liver, gallbladder, or biliary tree.[1],[2]
Patient Preparation
- Factors which can cause increased levels
- Prolonged fasting
- Factors which can cause decreased levels
- Exposure of sample to sunlight or bright artificial light at room temperature, high fat meal, air bubble and shaking of sample
Clinical Implications
Ranges: The following are the reference ranges for this lab. However, lab ranges can vary by laboratory and country. [2]
| Standard U.S. Units | Standard International Units | |
|---|---|---|
| Conventional Laboratory Range | 0-0.2 mg/dL | 0-3.4 umol/L |
| Optimal Range | 0-0.2 mg/dL | 0-3.4 umol/L |
| Alarm Ranges | > 0.8 mg/dL | > 13.7 umol/L |
High levels indicate:
- Biliary tract obstruction (due to liver dysfunction)
- Biliary duct obstruction (usually extra hepatic) / biliary calculi
Low levels indicate:
- low levels of direct bilirubin have no clinical significance
Associated Tests
- GGT, Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), serum alkaline phosphatase, bilirubin urine, urinary urobilinogen, RBC and indices, serum LDH
References
- ↑ Pagana Kathleen D, Pagana Timothy J, (1998) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby, Inc
- ↑ 2.0 2.1 Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain
