Xanthochromia

Test Alias / Common Abbreviations

CSF Xanthochromia

 

Department

 

Royal Stoke University Hospital, County Hospital, Leighton Hospital and Macclesfield District General Hospital                                                                                                                                                                                                                           

Pre-analytical information  

 

Add-on requests: NA

Minimum Retest Interval: A Lumbar puncture for xanthochromia must not be repeated for at least 2 weeks after the initial lumbar puncture (LP) due to the risk of producing a false-positive result. 

 

Sample  Collection instructions:

Collect at least 1 mL of CSF into a plain sterile bottle, protected from light. Also collect a paired blood sample for serum bilirubin and total protein.

The CSF sample should be collected >12 hours post-onset of headache and within 14 days.

The 4th (last) CSF fraction should be sent for analysis, as it is least likely to be contaminated by traumatic tap blood.

 

Sample Transport & Stability Information:

 

Samples should be sent to the laboratory on the same day as collection to ensure sample integrity is maintained.  If a delay in receipt of the sample is anticipated, please contact the laboratory to discuss storage requirements.

Do not send via pneumatic tube system. Transport to the laboratory by hand within 1 hour of collection. If delay is anticipated, please contact the laboratory urgently for storage advice.

Stable in separated CSF for 1 hour at room temperature and 1 day at 4-8oC. 

For generic information on test requesting, sample labelling and packaging, and sample transport – see the frequently asked questions here.

 

Sample Type, Container & Volume

Plain CSF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Turnaround Time

Based on receipt at testing site.

Within 24 hours. (weekdays)

 

 

 

 

 

Results are reported with an interpretative comment based on spectrophotometric analysis, performed in accordance with national guidelines (Revised national guidelines for analysis of cerebrospinal fluid for bilirubin in suspected subarachnoid haemorrhage; Cruickshank et al. Ann Clin Biochem 2008; 45: 238–244).

Results outside the reference range do not necessarily indicate disease. Similarly, results within the reference range do not preclude abnormality. Please contact the Duty Biochemist for discussion of individual patient results.

CSF analysis for xanthochromia is recommended when a CT scan is negative but clinical suspicion of subarachnoid haemorrhage remains high, or in patients presenting later after symptom onset.

Accuracy of results may be affected by sample timing relative to onset of symptoms, light exposure, pneumatic tube transport, previous lumbar puncture, hypercarotenaemia, iodine or contrast media contamination, and certain antibiotics (e.g. metronidazole, doxycycline, tetracycline). 

There are a number of non-pathological factors that can influence levels of specific analytes, giving falsely elevated or reduced levels. If you require more information regarding the effects of these factors on the individual test results, please contact the Duty Biochemist.

Serum/plasma samples are routinely screened for the presence of haemolysis, icterus and lipaemia. Results are not reported if one or more of these has been detected at levels deemed to have had a significant impact on the accuracy of the test.

Please indicate the following on the request form: Clinical indication, CT scan result, time of symptoms onset/event and the time of lumbar puncture.

Analysis is only routinely available during normal working hours. For urgent requests, please contact the laboratory to discuss. Urgent analysis may not be possible without prior discussion with on-call Duty Biochemist.

Reviewed / Updated On: 02/12/2025