Cerebrospinal Fluid Lactate Concentration Research Articles

The value of elevated cerebrospinal fluid lactate concentrations in post-neurosurgical bacterial meningitis

Bacterial meningitis is a serious complication after neurosurgery and has a high mortality rate. Early diagnosis and timely treatment are crucial or will have disastrous consequences. The classic triad of bacterial meningitis lacks sensitivity and specificity. Therefore, the diagnosis of post-neurosurgical bacterial meningitis relies on cerebrospinal fluid. But traditional cerebrospinal fluid parameters are not completely reliable in diagnosing post-neurosurgical bacterial meningitis. Previous studies have found that CSF lactate concentration is related to bacterial meningitis. But, after the craniocerebral operation, the cerebrospinal fluid of most patients is bloody. Whether red blood cells interfere with diagnosing PNBM based on lactate concentration is limited. In the current study, we further analysis on whether red blood cells interfere with diagnosing PNBM based on lactate concentration. This study aimed to investigate the value of cerebrospinal fluid lactate concentrations in post-neurosurgical bacterial meningitis. A prospective observational study was performed on 62 patients at Kunshan First People’s Hospital’s intensive care unit affiliated with Jiangsu University. We found that erythrocytes do not affect cerebrospinal fluid lactate, and elevated lactate concentrations can be used as a marker for postoperative bacterial meningitis.

Cerebrospinal fluid analysis of metabolites is not correlated to microdialysis measurements in acute brain injured patients

BackgroundCerebral microdialysis (CMD) has become an established bedside monitoring modality but its implementation remains complex and costly and is therefore performed only in a few well-trained academic centers. This study investigated the relationship between cerebrospinal fluid (CSF) and CMD glucose and lactate concentrations. MethodsTwo centers retrospective study of prospectively collected data. Consecutive adult (>18 years) acutely brain injured patients admitted to the Intensive Care Unit between 2010 and 2021 were eligible if CSF and CMD glucose and lactate concentrations were concomitantly measured at least once. ResultsOf 113 patients being monitored with an external ventricular drainage and CMD, 49 patients (25 from Innsbruck and 24 from Brussels) were eligible for the final analysis, including a total of 96 measurements. Median CMD glucose and lactate concentrations were 1.15 (0.51–1.57) mmol/L and 3.44 (2.24–5.37) mmol/L, respectively; median CSF glucose and lactate concentrations were 4.67 (4.03–5.34) mmol/L and 3.40 (2.85–4.10) mmol/L, respectively. For the first measurements, no correlation between CSF and CMD glucose concentrations (R2 <0.01; p = 0.95) and CSF and CMD lactate concentrations (R2 =0.16; p = 0.09) was found. Considering all measurements, the repeated measure correlation analysis also showed no correlation for glucose (rrm = −0.01; 95% Confidence Intervals −0.306 to 0.281; p = 0.93) and lactate (rrm = −0.11; 95% Confidence Intervals −0.424 to 0.236; p = 0.55). ConclusionsIn this study including acute brain injured patients, no correlation between CSF and brain tissue measurements of glucose and lactate was observed. As such, CSF measurements of such metabolites cannot replace CMD findings.

A preliminary study investigating the clinical potential of measuring cerebrospinal-fluid lactate levels in patients with narcolepsy type 1 and 2

Study objectivesBesides the quantification of orexin-A/hypocretin-1 cerebrospinal fluid (CSF) levels in narcolepsy for diagnostic purposes, several other CSF biomarkers have been evaluated, although with controversial results. Since CSF lactate concentrations fluctuate according to the sleep-wake cycle with higher levels during wakefulness and lower levels during sleep, as documented in animal model studies, the present study aimed at quantifying the CSF lactate levels in patients with narcolepsy type 1 (NT1) and 2 (NT2), which are two sleep disorders featured by excessive daytime sleepiness (EDS). MethodsPatients with NT1 and NT2 were enrolled in this study and compared to a control group of similar age and sex. All the subjects included in the study underwent a polysomnographic study followed by lumbar puncture for the quantification of CSF lactate levels at awakening. Results23 NT1 (43.5 % male; 36.43 ± 11.89 years) and 15 NT2 patients (46.7 % male; 37.8 ± 14.1 years) were compared to 17 controls (58.8 % male; 32.3 ± 8.4 years). CSF lactate concentrations were reduced in patients with NT1 and NT2 compared to controls but no differences were found between the two groups of patients. ROC curves analysis showed that CSF lactate ≤1.3 mmol/l had a sensitivity of 96.49 and a specificity of 82.35 % for discriminating patients with narcolepsy from controls. ConclusionsThe present study showed a decrease in CSF lactate levels in patients with narcolepsy. Notably, the reduction of lactate levels was present in both NT1 and NT2 patients, independently of CSF orexin levels. Narcolepsy patients present EDS with daytime napping and REM-related episodes, possibly substantiating the CSF lactate levels reduction related to the impaired daytime wakefulness which was demonstrated in animal studies. Moreover, CSF lactate levels present a good sensitivity and adequate specificity for differentiating narcolepsy from controls. Further studies are needed to understand the role of CSF lactate and its usefulness for monitoring daytime vigilance in patients with narcolepsy.

Cerebro-spinal fluid glucose and lactate concentrations changes in response to therapies in patIents with primary brain injury: the START-TRIP study

IntroductionAltered levels of cerebrospinal fluid (CSF) glucose and lactate concentrations are associated with poor outcomes in acute brain injury patients. However, no data on changes in such metabolites consequently to therapeutic interventions are available. The aim of the study was to assess CSF glucose-to-lactate ratio (CGLR) changes related to therapies aimed at reducing intracranial pressure (ICP).MethodsA multicentric prospective cohort study was conducted in 12 intensive care units (ICUs) from September 2017 to March 2022. Adult (> 18 years) patients admitted after an acute brain injury were included if an external ventricular drain (EVD) for intracranial pressure (ICP) monitoring was inserted within 24 h of admission. During the first 48–72 h from admission, CGLR was measured before and 2 h after any intervention aiming to reduce ICP (“intervention”). Patients with normal ICP were also sampled at the same time points and served as the “control” group.ResultsA total of 219 patients were included. In the intervention group (n = 115, 53%), ICP significantly decreased and CPP increased. After 2 h from the intervention, CGLR rose in both the intervention and control groups, although the magnitude was higher in the intervention than in the control group (20.2% vs 1.6%; p = 0.001). In a linear regression model adjusted for several confounders, therapies to manage ICP were independently associated with changes in CGLR. There was a weak inverse correlation between changes in ICP and CGRL in the intervention group.ConclusionsIn this study, CGLR significantly changed over time, regardless of the study group. However, these effects were more significant in those patients receiving interventions to reduce ICP.

High cerebrospinal fluid lactate concentration at 48 h of hospital admission predicts poor outcomes in patients with tuberculous meningitis: A multicenter retrospective cohort study.

ObjectiveThis study aimed to analyze the cerebrospinal fluid (CSF) parameters affecting the outcomes of patients with tuberculous meningitis (TBM).MethodsThis is a multi-center, retrospective, cohort study involving 81 patients who were diagnosed with TBM and treated in Haihe Clinical College of Tianjin Medical University, Tianjin Medical University General Hospital, and General Hospital of Air Force PLA from January 2016 to December 2019. Baseline data, Glasgow Coma Scale (GCS) score, and clinical presentations of all patients were collected at admission. CSF samples were collected at 48 h, 1, 2, and 3 weeks after admission. CSF lactate, adenosine deaminase, chloride, protein, glucose levels and intracranial pressure were measured. After a follow-up of 16.14 ± 3.03 months, all patients were assessed using the modified Rankin Scale (mRS) and divided into good (mRS scores of 0–2 points) and poor outcome groups (mRS scores of 3–6 points). The differences in patients' baseline data, GCS score, clinical presentations, and levels of CSF parameters detected at 48 h, 1, 2, and 3 weeks after admission between two groups were compared. Statistically significant variables were added to the binary logistic regression model to identify the factors impacting the outcomes of patients with TBM. Receiver operating characteristic (ROC) curve was used to assess the predictive ability of the model.ResultsThe CSF lactate level exhibited a decreasing trend within 3 weeks of admission in the two groups. For the within-group comparison, statistically significant differences in the lactate level was found in both groups between four different time points. A binary logistic regression model revealed that CSF lactate level at 48 h after admission, age, and GSC score on admission were independently associated with the outcomes of patients with TBM. ROC curve analysis showed that the area under the ROC curve (AUC) was 0.786 for the CSF lactate level (48 h), 0.814 for GCS score, and 0.764 for age.ConclusionHigh CSF lactate level at 48 h after admission is one of the important factors for poor outcomes in patients with TBM.

Time dependency of CSF cell count, lactate and blood-CSF barrier dysfunction after epileptic seizures and status epilepticus

BackgroundThis retrospective observational study was conducted to examine the temporal relationship between increased cell count, lactate concentration in cerebrospinal fluid (CSF) and blood-CSF barrier dysfunction and the onset of a seizure event. MethodsPatients with a seizure event who underwent lumbar puncture for CSF analysis during diagnostic work-up (interindividual analysis) and those with at least one follow-up CSF analysis (intraindividual analysis) were studied. Pathologically altered parameters, such as cell count, lactate concentration, and blood-CSF barrier dysfunction as indicated by the albumin quotient (QAlb=CSF albumin/serum albumin), were examined with regard to the changes over time after seizure onset. ResultsAn increased CSF cell count (>4/µl) was shown in 3% of our patients, whereas pathological lactate concentrations were found in 24% after single seizures and 28% after status epilepticus (SE)/recurring seizures. However, lactate levels showed a marked decrease with increasing time after an isolated seizure (p<0.0001) but not after SE/recurring seizures. Lactate levels were most frequently and significantly elevated within the first six hours after a single seizure (p<0.0001). Blood-CSF barrier dysfunction was detected in 34% after isolated seizures and in 47% after SE/recurrent seizures. Blood-CSF barrier dysfunction showed no association with latency between seizure onset and time of CSF collection. ConclusionsChanges in lactate and CSF protein concentrations are common after epileptic seizures. In contrast, CSF pleocytosis is uncommon and should prompt careful investigation for the presence of intrathecal infection or autoimmune CNS disease. Elevated lactate levels more than 6 h after the seizure event may indicate ongoing epileptic activity.

Population pharmacokinetics of vancomycin in patients with external ventricular drain-associated ventriculitis.

To determine the distribution of vancomycin into the cerebrospinal fluid (CSF) in patients with external ventricular drain (EVD)-associated ventriculitis, the pharmacokinetics of vancomycin were evaluated and covariate relationships explored. For the population pharmacokinetic model patients were recruited in a neurocritical care unit at the University Hospital of Muenster in the period between January 2014 and June 2015. All patients had a clinical evidence of EVD-associated ventriculitis. Population pharmacokinetic analysis of vancomycin was performed using NONMEM. A total of 184 blood and 133 CSF samples were collected from 29 patients. The final population pharmacokinetic model is a three-compartment model with linear elimination. Creatinine clearance (ClCr ) and CSF-lactate were detected as significant covariates, showing that the total vancomycin plasma clearance (Cl) depends on ClCr and furthermore the clearance (Cldif ) between the central and CSF compartment correlates with CSF lactate concentration. Based on the final model, the following values were estimated by NONMEM: Cl=5.15L/h, Q (intercompartmental clearance)=3.31L/h, Cldif =0.0031L/h, Vcentral =42.1L, VCSF =0.32L and the value of Vperipheral was fixed to 86.2L. With the developed pharmacokinetic model, area under the curve (AUC) values as well as CSF trough levels were simulated. Based on our analysis, the dosing of vancomycin should be referred to the degree of inflammation (derived from the CSF lactate concentration) and renal function (derived from ClCr ).

Association between cerebrospinal fluid lactate concentration and central nervous system disease in dogs.

Cerebrospinal fluid (CSF) analysis is a sensitive tool for evaluating patients with neurologic diseases but is rarely specific. Biomarkers can be measured from any bodily fluid and can be useful indicators for the presence, severity, and prognosis of diseases. This study was designed to evaluate if CSF lactate can be used as a biomarker in dogs with central nervous system disease. Peripheral venous blood and CSF were collected from 49 dogs with various intracranial diseases to evaluate correlations between blood and CSF lactate levels. Total nucleated cell count (TNCC) and CSF protein concentrations were also evaluated. All samples obtained were divided into normal (NG) and abnormal (AG) dogs based on a TNCC of ≤5 and >5cells/μL and a protein concentration of ≤25 and >25mg/dL, respectively. The AG dogs were further subdivided into those having <100 TNCCs/µL (AGL) and those having >100 TNCCs/µL (AGH). They were also subdivided into groups based on seizure activity (AGS), and inflammatory (AGI), or neoplastic diseases (AGN), and the respective lactate concentrations were then compared. Lactate concentrations were significantly increased in CSF and venous blood samples in the AG compared with the NG dogs, but no differences were found among the individual disease processes. In all dogs, CSF lactate concentrations were higher than venous blood lactate levels; however, no direct correlation between CSF and blood lactate concentrations was identified. Cerebrospinal fluid lactate can be used as a biomarker in clinical settings as it can be measured via a commercially available lactometer immediately after collection without the need for special instrumentation or laboratory personnel.

Cerebrospinal fluid lactate concentrations in dogs with seizure disorders.

BackgroundCerebrospinal fluid (CSF) lactate concentrations increase after seizure activity in many human patients independent of the underlying disease process. The effect of seizure activity on CSF lactate concentration in dogs is unknown.Hypothesis/ObjectivesCerebrospinal fluid lactate concentration is unaffected by seizure activity in dogs and is more dependent on the underlying disease process causing the seizures.AnimalsOne‐hundred eighteen client‐owned dogs with seizure disorders.MethodsCase series. Cerebrospinal fluid lactate concentration was determined using a commercially available lactate monitor. Seizure semiology, time from last seizure to CSF collection, number of seizures within the 72 hours preceding CSF collection, and clinical diagnosis were recorded.ResultsDogs with focal seizures had higher CSF lactate concentrations than did those with generalized seizures (P = .03). No differences in lactate concentrations were found among dogs with single seizures, cluster seizures or status epilepticus (P = .12), among dogs with CSF collection at different time points after the last seizure activity (P = .39) or among dogs having different numbers of seizures within the 72 hours preceding CSF collection (P = .42). A significant difference (P = .001) was found in CSF lactate concentrations among diagnostic groups, and dogs with inflammatory and neoplastic disease had higher concentrations than did dogs with idiopathic or unknown epilepsy.Conclusions and Clinical ImportanceCerebrospinal fluid lactate concentration is minimally affected by seizure activity in dogs and increased concentrations are more likely associated with the underlying disease process.

Clinical performance of amperometry compared with enzymatic ultra violet method for lactate quantification in cerebrospinal fluid.

The differential diagnosis between acute bacterial meningitis (BM) and viral meningitis (VM) is crucial for treatment and prognosis. Cerebrospinal fluid (CSF) lactate (LA) is considered a good biomarker for differentiating BM from VM. The objective of this study was to compare the clinical performance of amperometry, which is not validated for measurement of LA in CSF samples, with a validated method (enzymatic ultra violet), for their ability to discriminate between acute BM and VM. It was a retrospective, descriptive comparative study, 320 CSF reports were included; LA was quantified in CSF using either Dimension AR machine (Dade Behring) or amperometry (RAPID Point 500, Siemens). All samples with bacteria (n=54) or virus (n=139) identified, compared with a control with normal CSF (n=127). CSF LA levels were comparable for amperometry or enzymatic methods on each group studied, in a wide range of LA levels; it was capable to distinguish BM from VM independent of the method used to quantify. The findings support the use of the amperometric method in measuring LA concentrations in CSF in a wide range of values. Amperometry is a less expensive method, validated for blood, easily available in small laboratories including in limited resources countries.

Cisternal versus lumbar cerebrospinal fluid lactate concentration in healthy dogs

The analysis of cerebrospinal fluid biomarkers provides a wide range of information about the neurological health of a patient. Lactate is a metabolic precursor necessary for brain gluconeogenesis. When oxidative impairment or mitochondrial damage is present, lactate alteration occurs. The rostro-caudal dynamics of cerebrospinal biomarkers along the craniospinal axis in humans and horses was demonstrated in other studies. To the authors’ knowledge, no clinical study has, so far, investigated the cerebrospinal fluid lactate concentration in dogs in association with the puncture site. The purpose of this study was to compare the cerebellomedullary cistern and lumbar cistern cerebrospinal fluid lactate concentrations in healthy dogs. Cerebellomedullary and lumbar cerebrospinal fluids were collected for the cell count, total protein determination and lactate analysis from ten healthy Beagle dogs. The results revealed a significantly increased lumbar cerebrospinal fluid lactate concentration when compared with the cerebellomedullary cistern level. The results included: the total nucleated cell count &amp;lt; 5 cells/µl, the red blood cell count &amp;lt; 500 cell/µl, the total proteins &amp;lt; 0.3 g/l, as well as the cerebellomedullary lactate values (1.44 ± 0.06 mM/l) and the lumbar cistern lactate values (1.58 ± 0.1 mM/l). The results of this study highlight useful data that help to understand the physiological lactate variations depending on the cerebrospinal fluid puncture site.

Cerebrospinal fluid assessment in dogs with spinal tumors and intervertebral disk herniation

The study presents a retrospective case study. This aim was to determine whether lactate, glucose and total protein in serum and cerebrospinal fluid (CSF) can be used as specific biochemical markers for rapid differential diagnosis between intervertebral disk herniation and spinal tumors. Canine blood (n=9) and cerebrospinal fluid (n=9) were collected for chemistry analysis in nine dogs divided into two groups: intervertebral disk herniation group (IVDHG) (n=6) and spinal tumor group (TG) (n=3). Absorption spectrophotometry was used for quantitative determination of the concentrations of lactate, glucose and total protein in serum and CSF. Lactate concentration in serum and CSF and glucose concentration in CSF were 40-60% higher in subjects in TG compared to the IVDHG group. Serum lactate concentrations in the IVDHG group were 60% lower than physiological values. The results indicate that elevated concentration of glucose, lactate and total proteins in CSF and serum are indicative of a tumor, while a decrease of serum lactate and other parameters within normal range indicate disk herniation.

Increased Cerebrospinal Fluid Amyloid-β During Sleep Deprivation in Healthy Middle-Aged Adults Is Not Due to Stress or Circadian Disruption.

Concentrations of soluble amyloid-β (Aβ) oscillate with the sleep-wake cycle in the interstitial fluid of mice and cerebrospinal fluid (CSF) of humans. Further, the concentration of Aβ in CSF increases during sleep deprivation. Stress and disruption of the circadian clock are additional mechanisms hypothesized to increase CSF Aβ levels. Cortisol is a marker for stress and has an endogenous circadian rhythm. Other factors such as glucose and lactate have been associated with changes in sleep-wake activity and/or Aβ. In this exploratory study, we used samples collected in a previous study to examine how sleep deprivation affects Aβ, cortisol, lactate, and glucose in plasma and CSF from healthy middle-aged adults (N = 11). Eleven cognitively normal participants without evidence of sleep disturbance were randomized to sleep deprivation or normal sleep control. All participants were invited to repeat the study. Cortisol, lactate, glucose, and Aβ were measured in 2-h intervals over a 36-h period in both plasma and CSF. All concentrations were normalized to the mean prior to calculating mesor, amplitude, acrophase, and other parameters. One night of sleep deprivation increases the overnight concentration of Aβ in CSF approximately 10%, but does not significantly affect cortisol, lactate, or glucose concentrations in plasma or CSF between the sleep-deprived and control conditions. These data suggest that sleep deprivation-related changes in CSF Aβ are not mediated by stress or circadian disruption as measured by cortisol.

Cerebrospinal fluid and blood lactate concentrations as prognostic biomarkers in dogs with meningoencephalitis of unknown origin

Meningoencephalitis of unknown origin (MUO) is a common inflammatory disease of the central nervous system. Several studies investigated finding prognostic factors, but results are contradictory. The aim of this study was to determine the concentrations of blood lactate (Blood-L) and cerebrospinal fluid lactate (CSF-L) in dogs with MUO for prognostic purposes. A total of 45 dogs with MUO (MUO group) and 11 with idiopathic epilepsy (IE group) were included. In the MUO group, 22 dogs were treated with prednisolone + cytosine arabinoside, 17 with prednisolone ± cyclosporine, and six received no treatment.In the MUO group, there was a strong-moderate positive correlation between Blood-L and CSF-L (ρ = 0.63557; P < 0.0001), a strong-moderate negative correlation between survival and CSF-L (ρ= −0.50210; P < 0.0004), and a weak negative correlation between survival and Blood-L (ρ= −0.35685; P < 0.0220). Dogs with a favourable response to treatment at 1 month had lower initial concentrations of Blood-L and CSF-L (P < 0.0010; P < 0.0037), and those with a worse response had higher values (P < 0.0497; P < 0.0004). Dogs that remained stable with treatment showed lower CSF-L concentrations (P < 0.0013). Dogs with Blood-L>4 mmol/L (P < 0.03) and/or CSF-L> 4 mmol/L (P < 0.009) had lower survival rates with the latter also showing more severe signs, probably indicating severe neuronal damage. These findings suggest that concentrations of CSF-L and Blood-L in dogs with MUO could be used as prognostic indicators.

Reliability of a point-of-care blood gas analyzer for measuring lactate concentrations in cerebrospinal fluid

Reliability of a point-of-care blood gas analyzer for measuring lactate concentrations in cerebrospinal fluid

Cerebrospinal Fluid Lactate Concentration to Differentiate Bacterial from Viral Meningitis in Children

Ton Nu van Anh1*, Nguyen Huu Son2, Mai Thi Hien Uyen2, Nguyen Thi Diem Chi2, Nguyen Thi Hong Duc2 and Tran Vinh Phu1 Author Affiliations 1Pediatric Department, Hue University of Medicine and Pharmacy, Vietnam 2Pediatric Center, Hue Central Hospital, Vietnam Received: February 26, 2019 | Published: March 12, 2019 Corresponding author: Ton Nu van Anh, Pediatric Department, Hue University of Medicine and Pharmacy, Vietnam DOI: 10.26717/BJSTR.2019.15.002769 Also View In:

Glucose and Lactate Concentrations in Cerebrospinal Fluid After Traumatic Brain Injury.

Studies in which brain metabolism has been monitored using microdialysis have indicated decreases in cerebral glucose concentration and increases in lactate concentration in patients with traumatic brain injury (TBI). However, few data are available on glucose and lactate concentrations in the cerebrospinal fluid (CSF) of TBI patients. This study investigates the relationship between CSF glucose and lactate concentrations and outcomes after TBI. Consecutive adult (>18 y) TBI patients were admitted to our 35-bed medicosurgical between 2011 and 2014 and were included in the study if they met the following inclusion criteria: presence of an external ventricular drain (EVD) for intracranial pressure monitoring, daily analysis of CSF glucose and lactate concentrations for 4 consecutive days, and concomitant measurements of blood glucose/lactate concentrations. Neurological outcome was assessed at 3 months using the extended Glasgow Outcome Scale (GOS), and unfavorable outcome defined as a GOS 1 to 4. Of 151 TBI patients who had an EVD, 56 met the inclusion criteria. Most EVDs were placed on the day of intensive care unit admission, and maintained for 10 (interquartile range: 6 to 14) days. On day 1, there was a weak but significant correlation between blood and CSF glucose concentrations (R=0.07, P=0.04), and a greater correlation between blood and CSF lactate (R=0.32, P<0.001). In multivariable analysis, day 1 CSF glucose/lactate ratio was independently associated with mortality (odds ratio: 0.22, 95% confidence interval: 0.08-0.61; P=0.003), and day 1 CSF lactate concentration with unfavorable outcome (odds ratio: 4.86; 95% confidence interval: 1.86-12.67; P=0.001). Low CSF glucose/lactate ratio is observed in nonsurvivors after severe TBI and may have prognostic value.

Cerebrospinal Fluid Glucose and Lactate Levels After Subarachnoid Hemorrhage: A Multicenter Retrospective Study.

In patients with subarachnoid hemorrhage (SAH), abnormalities in glucose and lactate metabolism have been described using cerebral microdialysis. Glucose and lactate concentrations in cerebrospinal fluid (CSF) are more easily accessible, but scarce data are available in this setting. The aim of this study is to assess the relationship of CSF glucose and lactate with blood concentrations and with unfavorable neurological outcome after SAH. A retrospective cohort study was conducted in 5 European University intensive care units. Patients aged 18 years and above who were admitted after a nontraumatic SAH over a 4-year period (2011 to 2014) were included if they had an external ventricular drain placed, daily analysis of CSF including glucose (±lactate) concentrations for 1 to 4 consecutive days, and concomitant analysis of glucose and lactate concentrations in the arterial blood. A total of 144 patients were included in the final analysis (median age: 58 [49 to 66] y; male sex: 77/144). Median time from admission to external ventricular drain placement was 1 (0 to 3) day; median Glasgow Coma Scale on admission was 10 (7 to 13), and CT-scan Fisher scale was 4. A total of 81 (56%) patients had unfavorable neurological outcome at 3 months (Glasgow Outcome Scale ≤3). There was a weak correlation between blood and CSF glucose (r=0.07, P=0.007), and between blood and CSF lactate levels (r=0.58, P<0.001) on day 1, which were not influenced by insulin therapy. The presence of shock and low CSF glucose/lactate ratio were the only independent predictors of unfavorable outcome. CSF glucose and lactate levels poorly correlated with blood concentrations. Low CSF glucose/lactate ratio was associated with poor neurological outcome.

The combination of cerebrospinal fluid procalcitonin, lactate, interleukin-8 and interleukin-10 concentrations for the diagnosis of postneurosurgical bacterial meningitis: A prospective study.

The differential diagnosis between postneurosurgical bacterial meningitis and aseptic meningitis remains challenging both for the clinician and the laboratory. Combinations of markers, as opposed to single ones, may improve diagnosis and thereby survival. This prospective cohort study included patients with suspected bacterial meningitis after neurosurgery. The patients were divided into two groups according to the diagnostic criteria of meningitis involving a postneurosurgical bacterial meningitis group and a postneurosurgical aseptic meningitis group. Four biomarkers, including cerebrospinal fluid procalcitonin, lactate, interleukin-8 and interleukin-10 were assayed separately, and three algorithms were constructed using a linear combination. The area under the receiver operating characteristic curve was used to compare their performances. A cohort of 112 patients was enrolled in our study. Forty-three patients were diagnosed with postneurosurgical bacterial meningitis, and the cerebrospinal fluid values of their biomarkers were higher in patients with postneurosurgical bacterial meningitis than with postneurosurgical aseptic meningitis. The area under the receiver operating characteristic curves for the detection of postneurosurgical bacterial meningitis were 0.803 (95% confidence interval [CI], 0.724-0.883) for procalcitonin; 0.936 (95% CI, 0.895-0.977) for lactate; 0.771 (95% CI, 0.683-0.860) for interleukin-8; 0.860 (95% CI, 0.797-0.929) for interleukin-10; 0.937 (95% CI, 0.897-0.977) for the composite two-marker test; 0.945 (95% CI, 0.908-0.982) for the composite three-marker test and 0.954 (95% CI, 0.922-0.989) for the composite of all tests. The area under the receiver operating characteristic curves of the combination tests were greater than those of the single markers. Combining information from several markers improved the diagnostic accuracy in detecting postneurosurgical bacterial meningitis.

Importance of CSF lactate concentration in the diagnosis of acute bacterial meningitis

Editor – We read with interest the recent Clinical Medicine review by Griffiths et al [1][1] on management of acute meningitis, but were disappointed to note that there was no reference to the importance of biochemical analysis of cerebrospinal fluid (CSF) lactate concentration in the diagnosis of