Bilirubin (Total) (SBR) (conjugated bilirubin)

Chemical Pathology

Notes

Total bilirubin forms part of the liver function test profile as a marker of biliary obstruction. The test is also used to assess neonatal hyperbilirubinaemia.

Sample requirements

For adults, blood taken into a 5mL gold top tube (rust top for Acute Unit)

For children, blood taken into a 3.5mL rust top tube

For neonates, for a full liver function test profile, blood taken into a 0.8mL minicollect lithium heparin tube. Please list the tests of particular interest so that some priority can be given to analysis if plasma volumes are small.

If an assessment of neonatal jaundice is required then a heparinised capillary sample from a heel prick will suffice.

• Samples from the community should be taken into the orange top capillary tube and inserted into the brown outer tube for light protection.
  
• A minimum volume of 200 µL of blood is required (as shown in the central tube in the image below; the left hand tube is likely to provide insufficient plasma, depending on the haematocrit).

Storage/transport

Transport to the laboratory the same day at ambient temperature and avoiding exposure to light.

For neonatal bilirubin from the community the sample should be sent in an amber coloured outer tube or alternatively wrapped in brown paper to protect the sample from light.

Required information

Relevant clinical details. Medication or recent exposure to possible hepatotoxic agents. Recent foreign travel or contact with viral hepatitis.

Turnaround times

The assays are run throughout the day and night. The in-lab turnaround time is less than 24 hours. The test can be ordered as an urgent request.

For neonatal bilirubin results the expected turnaround time is usually less than 3 hours.

Reference ranges

• Adult total bilirubin reference range < 21 µmol/L
  
• Please refer to GHNHSFT local policy and to current NICE guidelines for up to date information on neonatal jaundice (links below)
  

Babies with prolonged jaundice (jaundice lasting more than 14 days in term or 21 days in pre-term) require a conjugated bilirubin level.

Conjugated bilirubin is assayed, when sample volumes permit, on all neonates with total bilirubin >60 µmol/L at ≥10 days old.

Further information

To learn more about bilirubin, visit External website Lab Tests Online or access the Bilirubin monograph of the Association for Clinical Biochemistry and Laboratory Medicine (pdf).

NICE CG98 Neonatal Jaundice (2010)

NICE CG98 Neonatal Jaundice Treatment Threshold Graphs

NICE CG98 Neonatal Jaundice: Threshold Table

Trust staff: Please refer to GHNHSFT policy A1091: Jaundice in Term and Preterm infants

Page last updated 05/06/2018