Analysis of cerebrospinal fluid for xanthochromia in the investigation of subarachnoid haemorrhage: experience of a state-wide, tertiary referral trauma centre

Subarachnoid haemorrhage (SAH) is spontaneous arterial bleeding into the subarachnoid space which is associated with high mortality and morbidity. To aid diagnosis, cerebrospinal fluid (CSF) can be examined for xanthochromia which is yellow discoloration, indicating the presence of bilirubin. The Department of Pathology offers a Monday-Friday (08:00-17:30), state-wide service for the detection of CSF xanthochromia. We audited our current service to assess clinical utility and the feasibility of offering a 24-hour laboratory CSF xanthochromia service. Seventy-eight CSF samples were received for xanthochromia testing from 2017-2018. There were no samples in which SAH was detected, and in one third of samples the patient was discharged prior to receiving the result. We estimated the base cost of offering a 24-hour CSF xanthochromia service would be $20,000, and the cost of analysing a sample out of working hours to be $2,600. Given the significant number of patients discharged prior to receiving the CSF xanthochromia result, a more targeted approach to the utilisation for this testing should be pursued.