Interpreting CSF Lactic Acidosis: Effect of Erythrocytes and Air Exposure

Venkatesh, B., Morgan, T. J., Boots, R. J., Hall, J. and Siebert, D. (2003) Interpreting CSF Lactic Acidosis: Effect of Erythrocytes and Air Exposure. Critical Care and Resuscitation, 5 3: 177-181.


Author Venkatesh, B.
Morgan, T. J.
Boots, R. J.
Hall, J.
Siebert, D.
Title Interpreting CSF Lactic Acidosis: Effect of Erythrocytes and Air Exposure
Journal name Critical Care and Resuscitation   Check publisher's open access policy
ISSN 1441-2772
Publication date 2003-09
Year available 2003
Sub-type Article (original research)
Volume 5
Issue 3
Start page 177
End page 181
Total pages 5
Place of publication Melbourne, Vic.
Publisher Australasian Medical Publishing Company
Language eng
Subject 110101 Medical Biochemistry: Amino Acids and Metabolites
Formatted abstract
Objective:

Elevated cerebrospinal fluid (CSF) lactate concentrations in neurotrauma and sub-arachnoid haemorrhage are associated with a poor prognosis. However, in blood-stained CSF, elevated lactate levels may arise from red cell metabolism, even without ischaemia, potentially reducing specificity. This study was undertaken to quantify the erythrocyte contribution to CSF lactate measurements, with and without, exposure to room air.

Methods:

Blood was added to CSF to achieve three different red cell concentrations. The CSF was then exposed at 37°C to either room air or 5% CO2 and 95% oxygen. Vancomycin and gentamycin were added to inhibit bacterial growth. Lactate concentrations and red cell concentrations were measured prior to the addition of blood and 10 minutes, 6 hours and 24 hours later. CSF without the addition of blood was used as a control.

Results:

In the control specimens there were no increases in CSF lactate concentrations over time, either in air or CO2, whereas all specimens with blood added demonstrated significant increases in lactate at 6 and 24 hours (P < 0.01). The lactate increases in both air and CO2 were correlated directly with red cell counts (R2 = 0.62 to 0.87). At all red cell concentrations, the mean lactate increase was greater in air.

Conclusions:

Red cells in CSF cause significant increases in lactate concentrations, more so when exposed to air. This should be considered when interpreting lactate in blood stained CSF. Blood-stained CSF specimens for lactate assay should be collected directly from an external ventricular drain rather than a reservoir bag.
Keyword cerebrospinal fluid
lactate
alkalosis
drain
haemorrhagic
ventricular
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Medicine Publications
 
Versions
Version Filter Type
Citation counts: Google Scholar Search Google Scholar
Created: Wed, 01 Apr 2009, 12:41:32 EST by Mary-Anne Marrington on behalf of Anaesthesiology and Critical Care - RBWH