Point-of-care Detection of Lactate in Cerebrospinal Fluid

Abstract

Purpose: Measurements of cerebrospinal fluid (CSF)-lactate can aid in detecting infections of the central nervous system and surrounding structures. Neurosurgical patients with temporary lumbar or ventricular CSF-drainage harbor an increased risk for developing infections of the central nervous system which require immediate therapeutic responses. Since blood-gas-analyzers enable rapid blood-lactate-measurements we were interested to find out if CSF-lactate may be reliably measured by this point-of-care technique. Methods: Neurosurgical patients on our intensive care unit (ICU) with either lumbar or external ventricular drainage due to a variety of reasons were included in this prospective observational study. Standard of care included measurements of leucocyte counts, total protein and lactate measurements in CSF by the neurochemical laboratory of our University Medical Center twice a week. With respect to this study we additionally performed nearly daily measurements of cerebrospinal-fluid by blood gas analyzers to determine the reliability of CSF-lactate measured by blood-gas-analyzers as compared to the standard measurements with a certified device. Results: 62 patients were included in this study. 514 CSF measurements were performed with blood-gas-analyzers. 180 of these could be compared to the in-house standard CSF-lactate measurements. Both techniques correlated highly significant (Pearson correlation index 0.94) even though lacking full concordance in a Bland-Altman-plotting. Of particular importance, regular measurements enabled immediate detection of central infection in 3 patients who had developed meningitis during the course of their treatment.Conclusion: CSF-lactate was reliably measured by blood-gas-analyzers and detected developing meningitis timely. In addition to and triggering established CSF-diagnostics, CSF-lactate measurements by blood-gas-analyzers may improve surveillance of central nervous infections in patients with CSF-drainage. This study was retrospectively registered on April 20th 2020 in the German trial register. The trial registration number is: DRKS00021466.