Published Online
on August 31, 2006

A more recent version of this article appeared on October 1, 2006

This Article Full Text (PDF) All Versions of this Article: 37/10/2467    most recent 01.STR.0000240689.15109.47v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Perry, J. J. Articles by Symington, C. Search for Related Content PubMed PubMed Citation Articles by Perry, J. J. Articles by Symington, C. Related Collections Cerebral Aneurysm, AVM, & Subarachnoid hemorrhage Other Stroke Treatment - Medical Aneurysm, AVM, hematoma

Submitted on December 22, 2005
Revised on June 23, 2006
Accepted on June 28, 2006

Should Spectrophotometry Be Used to Identify Xanthochromia in the Cerebrospinal Fluid of Alert Patients Suspected of Having Subarachnoid Hemorrhage?

Jeffrey J. Perry MD, MSc^*; Marco L.A. Sivilotti MD, MSc; Ian G. Stiell MD, MSc; George A. Wells PhD; Jenny Raymond PhD; Melodie Mortensen BScRN; and Cheryl Symington RN, ENCc

From the Department of Emergency Medicine (J.J.P., I.G.S., M.M., C.S.), University of Ottawa, ON, Canada; the Departments of Emergency Medicine and of Pharmacology & Toxicology (M.L.A.S.), Queen’s University, Kingston, ON, Canada; the Department of Epidemiology and Community Medicine (G.A.W.), University of Ottawa, ON, Canada; the Department of Pathology and Molecular Medicine (J.R.), Queen’s University, Kingston, ON, Canada; and the Department of Emergency Medicine, University of Ottawa, ON, Canada.

^* To whom correspondence should be addressed. E-mail: jperry{at}ohri.ca.

Background and Purpose--The absence of xanthochromia in the cerebrospinal fluid (CSF) is often used to exclude subarachnoid hemorrhage (SAH). Authorities advocate spectrophotometry to measure xanthochromia, but most North American hospitals use visual inspection. We studied the diagnostic accuracy of spectrophotometry for SAH, and its potential impact on current practice.

Methods--This was a prospective cohort study comparing the diagnostic accuracy of tests. The study was set in 3 university-affiliated tertiary care emergency departments. We enrolled consecutive neurologically intact adults with nontraumatic headache undergoing lumbar puncture (LP) to rule out SAH. CSF was centrifuged, frozen and analyzed later in batch. SAH was defined by (1) subarachnoid blood on CT, (2) >5x10⁶ red blood cells/L in the final CSF tube and positive angiography, or (3) visible xanthochromia in CSF and positive angiography. All subjects lacking a normal CT and LP were telephoned at 30 days.

Results--We enrolled 220 patients (mean age 42±16 years; CT rate 87.7%; angiography rate 5.9%). Two SAHs were identified: 1 with red blood cells without xanthochromia in the CSF and 1 with visibly xanthochromic CSF. The specificity of xanthochromia was 97% (95% CI: 92% to 99%) for visual inspection, but as low as 29% (95% CI: 23% to 35%) for 2 of the spectrophotometric definitions. Introducing spectrophotometry could lead to angiography in as many as 11% to 71% of patients undergoing LP.

Conclusions--Spectrophotometric definitions of xanthochromia have only moderate to low specificity for SAH. Using spectrophotometry could increase angiography rates, thereby identifying more incidental aneurysms, increasing patient anxiety and exposing patients to unnecessary surgical or investigational complications without benefit.

Key words: cerebrospinal fluid • spectrophotometry • subarachnoid hemorrhage

This article has been cited by other articles:

				S. A. Dupont, E. F. M. Wijdicks, E. M. Manno, and A. A. Rabinstein Thunderclap Headache and Normal Computed Tomographic Results: Value of Cerebrospinal Fluid Analysis Mayo Clin. Proc., December 1, 2008; 83(12): 1326 - 1331. [Abstract] [Full Text] [PDF]

				EMQ answers Emerg. Med. J., July 1, 2008; 25(7): 464 - 464. [Full Text] [PDF]

				I. D Watson, R. Beetham, M. N Fahie-Wilson, I. B Holbrook, and D. M O'Connell What is the role of cerebrospinal fluid ferritin in the diagnosis of subarachnoid haemorrhage in computed tomography-negative patients? Ann Clin Biochem, March 1, 2008; 45(2): 189 - 192. [Abstract] [Full Text] [PDF]

				L. E. Nigrovic, M. Trivedi, J. A. Edlow, and M. I. Neuman Cerebrospinal Fluid Xanthochromia in Newborns Is Related to Maternal Labor Before Delivery Pediatrics, November 1, 2007; 120(5): e1212 - e1216. [Abstract] [Full Text] [PDF]

				R. Beetham and S. Lhatoo Should Spectrophotometry Be Used to Identify Xanthochromia in the Cerebrospinal Fluid of Alert Patients Suspected of Having Subarachnoid Hemorrhage? Stroke, September 1, 2007; 38(9): e86 - e86. [Full Text] [PDF]

				J. J. Perry and M. L.A. Sivilotti Response to Letter by Beetham and Lhatoo Stroke, September 1, 2007; 38(9): e87 - e87. [Full Text] [PDF]