Cerebrospinal Fluid Lactate in the Diagnosis of Meningitis: Diagnostic Value Compared to Standard Biochemical Methods

Abstract

Cerebrospinal fluid (CSF) lactate was determined in 245 patients by means of a rapid enzymatic method (Monotest Lactate). The mean value was 1.61 mmol/l (range 0.79-3.33) in 104 control patients, 2.06 mmol/l (range 0.76-4.31) in 121 patients with aseptic meningitis, and 8.18 mmol/l (range 1.77-19.21) in 20 patients with bacterial meningitis. In most of the patients CSF protein and the CSF/blood glucose quotient were also determined. Lactate and glucose quotient differentiated equally well between aseptic and bacterial meningitis while protein was somewhat less useful. Suitable values for discrimination between aseptic and bacterial meningitis were judged to be 3.0 mmol/l for CSF lactate, 1.0 g/l for CSF protein and 0.5 for the glucose quotient. Combinations of tests improved the diagnostic accuracy in aseptic but not in bacterial meningitis. In 2 patients with bacterial meningitis all tests failed. CSF lactate may be used as a supplementary aid in the diagnosis of meningitis. Its diagnostic efficacy was equal to but not better than that of the traditional methods.

A Proteomic Approach for the Diagnosis of Bacterial Meningitis

“…CSF-leukocyte counts can be lower than 100/µl [22] heralding a severe clinical course, the CSF-leukocyte differentiation is also not an accurate tool: when the leukocyte count is below 1000/µl, more than 30% of patients show a CSF-lymphocytosis [23]. CSF-lactate concentration seems to be more reliable [24], here a cut-off value of 3.0 mmol/l was proposed by Berg and co-workers [6]. Nevertheless, two of their patients in rather early stages showed lactate concentrations below this cut-off.…”

“…Meningism is often missing especially in elderly patients [1] and young children [3]. Typical laboratory parameters in patients with bacterial meningitis are elevated CSF-leukocytes ≥1000/µl [4], CSF-protein ≥1 g/l [5], and CSF-lactate >3.0 mmol/l [6]. In blood samples, increase of leukocytes and of C-reactive protein (CRP, usually ≥100 µg/ml) can be found [7].…”

Cerebrospinal fluid lactate in post-neurosurgical bacterial meningitis diagnosis

“…CSF acidosis due to bacterial infection has been known for a long time [12][13][14], and CSF lactate has been available circa 1920. However, despite its use in the pediatric population to differentiate between bacterial and viral meningitis [11,20], the use of CSF lactate in the adult population has been limited because of the availability of the test and questions that arose regarding its utility [2]. The CSF lactate threshold proposed was between 3.5 and 4 mmol/L, achieving an acceptable sensitivity and specificity [17,18].…”

Lumbar punctures: use and diagnostic efficiency in emergency medical departments

“…While standard CSF tests are known to provide valuable support in differentiating bacterial from aseptic (lymphocytic) meningitis [32], some authors have suggested that these standard tests are only moderately useful in the event of a negative Gram-stained smear [19, 33, 34]. Other specific CSF and blood serum tests have been proposed to better appreciate the likelihood of bacterial meningitis [18, 35]. …”

“…Hence, there is a need for further investigations to explore the use and the efficiency of LP performed in the EMD. The main associated investigations, such as computed tomography (CT) of the brain prior to LP [3, 12–17] and CSF tests [18–20], are also important to assess.…”