Test Details
Methodology
Colorimetric
Result Turnaround Time
Within 1 day
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Evaluate liver and biliary disease. Increased direct bilirubin occurs with biliary diseases, including both intrahepatic and extrahepatic lesions. Hepatocellular causes of elevation include hepatitis, cirrhosis, and advanced neoplastic states. Increased with cholestatic drug reactions, Dubin-Johnson syndrome, and Rotor syndrome. In the latter two syndromes, the level is usually <5 mg/dL.
Contraindications
Custom Additional Information
Theoretically, direct bilirubin should not be increased in hemolytic anemias, in which bilirubin increase should be in the indirect bilirubin fraction in the absence of complications. In practice, some increase in the direct fraction may be encountered in patients with hemolytic anemia in whom complications have not been proven. Some methods have shown the direct bilirubin to be spuriously high. This may be due to different concentrations of sodium nitrite, which may convert some of the unconjugated bilirubin to conjugated bilirubin.1,2 Direct bilirubin is the water soluble fraction. When increased in serum, bilirubin should become positive in the urine. Physiologic jaundice, occurring two to four days after birth, is due to lack of liver glucuronyl transferase.
Specimen Requirements
Specimen
Serum (preferred) or plasma
Volume
1 mL
Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.
Collection Instructions
Separate serum or plasma from cells within 45 minutes of collection.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 2 days |
Refrigerated | 3 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
See table.
Age | Range (mg/dL) |
|---|---|
0 to 31 d | 0.00−0.60 |
Children 1 month and older and adults | 0.00−0.40 |
Storage Instructions
Refrigerate
Causes for Rejection
Gross hemolysis; improper labeling; gross lipemia
Footnotes
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 001222 | Bilirubin, Direct | 1968-7 | 001222 | Bilirubin, Direct | mg/dL | 1968-7 |
| Order Code | 001222 | |||||
| Order Code Name | Bilirubin, Direct | |||||
| Order Loinc | 1968-7 | |||||
| Result Code | 001222 | |||||
| Result Code Name | Bilirubin, Direct | |||||
| UofM | mg/dL | |||||
| Result LOINC | 1968-7 |