Jump to ContentJump to Main Navigation
Show Summary Details

Clinical Chemistry and Laboratory Medicine (CCLM)

Published in Association with the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)

Editor-in-Chief: Plebani, Mario

Ed. by Gillery, Philippe / Lackner, Karl J. / Lippi, Giuseppe / Melichar, Bohuslav / Payne, Deborah A. / Schlattmann, Peter / Tate, Jillian R.


IMPACT FACTOR increased in 2015: 3.017
Rank 5 out of 30 in category Medical Laboratory Technology in the 2014 Thomson Reuters Journal Citation Report/Science Edition

SCImago Journal Rank (SJR) 2015: 0.873
Source Normalized Impact per Paper (SNIP) 2015: 0.982
Impact per Publication (IPP) 2015: 2.238

Online
ISSN
1437-4331
See all formats and pricing

 


Select Volume and Issue

Issues

30,00 € / $42.00 / £23.00

Get Access to Full Text

An improved laboratory protocol to assess subarachnoid haemorrhage in patients with negative cranial CT scan

Joke J. Apperloo1 / Fedde van der Graaf2 / Paul L.I. Dellemijn3 / Huib L. Vader4

1.

2.

3.

4.

Corresponding author: Joke J. Apperloo, PhD, Laboratory of Clinical Chemistry, Máxima Medical Centre, De Run 4600, 5500 MB Veldhoven, The Netherlands Phone: +31-40-8888900, Fax: +31-40-8888909,

Citation Information: Clinical Chemical Laboratory Medicine. Volume 44, Issue 8, Pages 938–948, ISSN (Online) 1437-4331, ISSN (Print) 1434-6621, DOI: https://doi.org/10.1515/CCLM.2006.171, July 2006

Publication History

Received:
November 3, 2005
Accepted:
May 3, 2006
Published Online:
2006-07-31

Abstract

Background: The laboratory analysis of cerebrospinal fluid (CSF) plays a key role in considering subarachnoid haemorrhage (SAH) in patients with clinical suspicion, but negative CT scan. Although the determination of the CSF bilirubin concentration generally provides high sensitivity, it was recently shown that specificity and positive predictive value are unacceptably low, limiting its use as a diagnostic tool.

Methods: We intended to design and evaluate an improved laboratory protocol, which fulfills the requirement of better specificity without losing sensitivity. We present a procedure in which a “bili-excess” concentration is determined, which is the surplus CSF bilirubin measured after subtraction of an estimated upper limit for the individual patient. The latter is calculated from [bilirubin]serum, [albumin]serum and [albumin]CSF, taking into account the propagation of analytical errors in the individual analyses. We investigated the applicability of direct absorption vs. derivative spectroscopy, thereby addressing the influence of various calibration methods. We evaluated our procedure in 92 CSF samples drawn from patients with (n=37) and without (n=55) clinical suspicion of SAH.

Results: In our study population, we show that specificity increases from 0.83 (95% CI, 0.74–0.91) to 1.00 (95% CI, 0.96–1.00) using the bili-excess concept, with an established upper limit for bili-excess of 0.11 μmol/L instead of the recommended use of an “uncorrected” CSF bilirubin upper limit of 0.20 μmol/L. Sensitivity in both cases is 1.00 (95% CI, 0.66–1.00). We demonstrate the merit of allowing for analytical imprecision in the bili-excess concept.

Conclusions: We provide a quantitative procedure to explore the likelihood of (CT-negative) SAH independent of the absolute CSF bilirubin concentration by considering the “bili-excess” concentration per individual, using derivative spectroscopy to determine CSF bilirubin. This procedure led to an increase in specificity to 1.00 (95% CI, 0.96–1.00) in our study population.

Clin Chem Lab Med 2006;44:938–48.

Keywords: bili-excess; bilirubin; blood pigments; cerebrospinal fluid; subarachnoid haemorrhage

Citing Articles

Here you can find all Crossref-listed publications in which this article is cited. If you would like to receive automatic email messages as soon as this article is cited in other publications, simply activate the “Citation Alert” on the top of this page.

[1]
N. A. Bakker, R. J. M. Groen, M. Foumani, M. Uyttenboogaart, O. S. Eshghi, J. D. M. Metzemaekers, G. J. Luijckx, and J. M. C. Van Dijk
Journal of Neurology, Neurosurgery & Psychiatry, 2014, Volume 85, Number 8, Page 885
[2]
I. M. E. Alons, R. J. Verheul, G. A. E. Ponjee, and K. Jellema
European Journal of Neurology, 2013, Volume 20, Number 1, Page 193

Comments (0)

Please log in or register to comment.