CSF xanthochromia: correlation with brain imaging and its usefulness as an out-of-hours test.
BACKGROUND
Subarachnoid haemorrhage (SAH) is a spontaneous bleed into the subarachnoid space which is investigated by CT head and cerebrospinal fluid (CSF) xanthochromia. The aim of this study was to compare CSF xanthochromia with brain imaging and evaluate the need for out of hours (OOH) testing for CSF xanthochromia.


METHODS
Discharge summaries and brain imaging of patients with positive xanthochromia screen were reviewed over 12 months retrospectively. Timings of CSF xanthochromia and hospital discharge of 30 consecutive patients with negative xanthochromia screen were also examined.


RESULTS
From 289 xanthochromia requests, 23 were positive but only 2 patients had an actual bleed. In 30 consecutive negative xanthochromia results, all brain imaging results suggested no bleed. Eight of these requests were performed OOH, and as a result, 1 patient was discharged early.


CONCLUSIONS
CSF xanthochromia has a poor positive predictive value (8.7%) but has a good negative predictive value (100%) for SAH. Analysis of CSF xanthochromia OOH, in patients with negative CT head, did not speed up the discharge process from the hospital.
Department of Clinical Pathology, Nottingham University Hospitals, Nottingham, UK.
Farhan
F
Ahmed
Department of Clinical Pathology, Nottingham University Hospitals, Nottingham, UK.
Stephen
S
Gibbons
Department of Clinical Pathology, Nottingham University Hospitals, Nottingham, UK.
Alia
A
El-Kadiki
D006801:Humans; D059906:Neuroimaging; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed
Analytical Methods; Biochemistry; CSF Biochemistry