Laboratory Medicine
Test Directory / CSF Xanthochromia
CSF Xanthochromia
White topped universal (no additives)
| Test | CSF Xanthochromia |
|---|---|
| Common Abbreviations | Xantho CSF Scan |
| Profile | NA |
| Tube type | White topped universal (no additives) |
| Clinical Indication | Analysis of CSF is used as a second line investigation in those patients whose CT scan was negative where there is a strong clinical suspicion of SAH as well as in those patients who present late. Haemoglobin and bilirubin do not normally cross the blood brain barrier except through haemorrhage. Following the appearance of blood in the CSF the erythrocytes lyse and liberate oxyhaemoglobin which is then converted to bilirubin. Oxyhaemoglobin can be associated with recent bleeding into CSF and trauma during the lumbar puncture. The presence of oxyhaemoglobin and bilirubin in CSF is suggestive of SAH. |
| Specimen Type | CSF |
| Sample type | CSF (protected from the light) |
| Minimum Volume | 200µl |
| Special Precautions | Protect from light. Transport to laboratory by hand. Ensure >12 hours since onset of headache. Certain antibiotics (metronidazole, doxycycline, tetracycline) may interfere in CSF xanthochromia scan and cause false negative results. Contrast media may interfere in CSF xanthocromia scan. Scan may not be interpretable. |
| Stability | <1 hour if not light protected and at least 24 hours if light protected |
| Turnaround Time | Urgent: 4 hours Non-Urgent: 12 hours |
| Laboratory | York |
| Reference Interval | Interpretative result provided The net bilirubin absorbance (NBA) is reported as a numerical value with a cut off level of 0.007 between suspicion or exclusion of a subarachnoid haemorrhage (SAH) event. The net oxyhaemoglobin absorbance is reported as detected or not detected with a cut off level of 0.02. |
| Limitations | Samples must be collected greater than 12 hours and less that 2 weeks since the onset of headache. High CSF oxyhaemoglobin, CSF total protein or serum bilirubin may affect interpretation. |
| Notes |
