Spectrophotometry & visual inspection for xanthochromia: Results from a four-year state-wide dataset

Abstract

Introduction: Opinions are polarised regarding the use of spectrophotometry versus visual inspection for the detection of xanthochromia in suspected subarachnoid haemorrhage (SAH). Objectives: To describe the test characteristics for spectrophotometry and visual inspection of the cerebrospinal fluid (CSF). Method: State-wide spectrophotometry results for public hospital patients age ≥18years were sourced from Pathology Queensland from 1-1-2010 to 30-6-2014. Appearance of CSF supernatant, levels of CSF bilirubin and oxyhaemoglobin, and their pre-defined laboratory interpretations were abstracted. Imaging results including angiography were sourced from state-wide public hospital databases. A cerebral aneurysm was considered present if detected on angiography. A cerebral aneurysm was considered absence if it was not detected on angiography, and the patient was not subsequently diagnosed with a SAH or died on review of state-wide databases. Results: Xanthochromia was requested for 3,664 CSF samples. Median (range) age was 45 (18-98) years. 56% were females. CSF was bloodstained in 13.8%. CSF supernatant was colourless, yellow and not reported in 89.9%, 1.4% and 8.4%, respectively. Spectrophotometry was reported as no evidence of SAH, consistent with SAH, and indeterminate, and no test in 97.1%, 1.8%, 0.5%, and 0.5%, respectively. Angiography was performed in 8.7%. There were 62 (1.7%) cerebral aneurysms and 2 arteriovenous malformations on angiography. These results are currently being linked to state-wide databases to determine whether subsequent SAH diagnosis or death has occurred within 3months of the CSF examination. Conclusion: CSF examination continues to have a role in the diagnosis of SAH in patients with a normal CT head scan.<br />