Lactic acid is of low predictive value for the diagnosis of bacterial infection in ventricular cerebrospinal fluid samples containing residual blood.
BACKGROUND
Lactic acid concentrations (LA) are an established marker of bacterial infection in cerebrospinal fluid (CSF). However, use of LA for the detection of infection in CSF with residual blood has not been fully evaluated.


METHODS
Analysis of LA and total protein, cell count and bacterial culture were performed in 90 lumbar and ventricular CSF samples contaminated with blood.


RESULTS
Bacterial culture was positive in six CSF samples. The diagnostic value of the cell count was significantly higher than that of LA for the prediction of a positive culture, even if all culture positive and all likely infected samples were included in the analysis. There was no significant difference in LA concentrations between positive or likely positive ventricular CSF samples and all negative, ventricular samples.


CONCLUSIONS
Although LA concentrations in CSF are evidently a predictor of bacterial infection, its diagnostic value for the detection of bacterial infection in ventricular CSF with residual blood is limited.
Böer
Klas
K
Institut fuer Klinische Chemie und Laboratoriumsdiagnostik, FSU Jena, Jena, Germany. kboeer@med.uni-jena.de
Pfister
Wolfgang
W
Kiehntopf
Michael
M
D001424:Bacterial Infections / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D015415:Biomarkers; D001773:Blood Cells; D002555:Cerebrospinal Fluid / Q000166:cytology; D006801:Humans; D019344:Lactic Acid / Q000134:cerebrospinal fluid*; D011237:Predictive Value of Tests
D015415:Biomarkers; D019344:Lactic Acid