Brief ReportCerebrospinal fluid/blood glucose ratio as an indicator for bacterial meningitis☆
Introduction
Bacterial meningitis is an emergent, life-threatening, infectious disease which requires prompt diagnosis and appropriate antimicrobial therapy. Keeping meningitis in mind as a differential diagnosis, the physician should perform a lumbar puncture if none of the clinical findings can adequately rule out this disease [1]. The presence of pleocytosis confirms the diagnosis of meningitis, but it may not always predict the presence of bacterial meningitis, which requires treatment with antimicrobials. The use of empiric antimicrobials is justified if the physician suspects bacterial meningitis; however, whenever possible, the physician should refrain from administering antimicrobials without adequate medical grounds for their use.
The association between emergency laboratory examinations of cerebrospinal fluid (CSF) and the diagnosis of bacterial meningitis has rarely been reassessed since the 1980s [2], [3], [4]. A recent study reported that CSF lactate concentration is a better, single indicator for predicting bacterial meningitis than conventional markers such as CSF glucose, CSF/blood glucose ratio, CSF protein and CSF total number of leukocytes [5], [6]. However, the CSF lactate level is likely to be affected by the administration of antimicrobials [6], and measuring CSF lactate is not routinely performed. Several management guidelines for bacterial meningitis have noted that the measurement of conventional markers in CSF should be considered when assessing the possibility of bacterial meningitis. Given the lack of recent studies examining the utility of emergency laboratory examinations of CSF for predicting the presence of bacterial meningitis, we investigated the diagnostic value of this method for predicting bacterial meningitis at a Japanese tertiary care center.
Section snippets
Study setting
This study was conducted at the Tokyo Metropolitan Tama Medical Center, a 789-bed tertiary care teaching hospital in Tokyo, Japan. The emergency department (ED) at this institution takes in an average of approximately 38,000 patients, including 7,200 ambulances, annually. The study was approved by the institutional review board of Tokyo Metropolitan Tama Medical Center with a waiver of informed consent to review the patient records.
Study design and participants
The current retrospective study consists of a review of medical
Results
A total of 573 patients who underwent a lumbar puncture between January 1, 2006, and November 31, 2012, were identified. Fifty-two of these patients were excluded because they met the exclusion criteria (hydrocephalus: 11, subarachnoid hemorrhage: 7, traumatic tap: 5, Guillain-Barré syndrome: 5, multiple sclerosis: 3, neurosarcoidosis: 2, central nervous system metastasis: 2, HIV encephalopathy: 1, and incomplete medical record: 6). We subsequently excluded 10 additional cases of meningitis
Discussion
Although the use of empiric antimicrobials is justified if the physician suspects bacterial meningitis after a comprehensive examination of the patient’s medical history and symptoms, the present study suggests that the CSF/blood glucose ratio has demonstrable utility for the diagnosis of bacterial meningitis, and may thus expedite the physician’s decision as to whether or not to administer antimicrobials.
The several studies assessing CSF analysis in patients with meningitis were mostly
Conclusion
This study demonstrates that the CSF/blood glucose ratio may predict the presence of bacterial meningitis more precisely than other routinely measured markers in CSF. Since the CSF glucose levels and blood glucose levels are promptly available, the CSF/blood glucose ratio should be examined as a timely diagnostic indicator for bacterial meningitis. To assess the presence of bacterial meningitis comprehensively, the CSF/blood glucose ratio in combination with other signs, symptoms, and
Declaration
We investigated the same cohort in another article [1]. However the subjects of the articles are independent of one another.
Acknowledgments
We thank Dr Hiroyoshi Y. Tanaka for his reading of the manuscript and his suggestions for improving its contents, Dr Keita Tatsuno for his various invaluable suggestions, Mr Keigo Morita for his unflagging diligence in gathering the references, and all of the staff and patients who contributed to this study.
References (12)
- et al.
Absence of jolt accentuation of headache cannot accurately rule out meningitis in adults
Am J Emerg Med.
(2013) - et al.
Diagnostic accuracy of cerebrospinal fluid lactate for differentiating bacterial meningitis from aseptic meningitis: a meta-analysis
J Infect.
(2011) - et al.
Accuracy of the cerebrospinal fluid results to differentiate bacterial from non bacterial meningitis, in case of negative gram-stained smear
Am J Emerg Med.
(2007) - et al.
Comments on "Accuracy of the cerebrospinal fluid results to differentiate bacterial from non bacterial meningitis, in case of negative gram-stained smear"
Am J Emerg Med.
(2008) - et al.
How do I perform a lumbar puncture and analyze the results to diagnose bacterial meningitis?
JAMA
(2006) Comparison between cerebrospinal fluid concentrations of glucose, total protein, chloride, lactate, and total amino acids for the differential diagnosis of patients with meningitis
Scand. J. Infect. Dis.
(1983)
Cited by (65)
High risk and low prevalence diseases: Adult bacterial meningitis
2023, American Journal of Emergency MedicineCitation Excerpt :CSF specimens should be sent for Gram stain and culture, cell count and differential, protein, and glucose [8]. CSF specimens should be assessed with simultaneous blood specimens, as the CSF/blood glucose ratio is more informative as a diagnostic indicator of bacterial meningitis than CSF glucose alone [20]. A point-of-care blood gas analyzer can be used to determine blood and CSF glucose; however, capillary glucose should not substitute serum glucose to determine the CSF/blood glucose ratio [21,22].
Cerebrospinal fluid glucose is not altered in patients with dementia
2023, Clinical BiochemistryCitation Excerpt :Normally, there is a close relationship between CSF and plasma glucose concentrations, and the ratio ranges between 0.5 and 0.8 [4], but the ratio may change in different pathological conditions. Thus, the CSF/plasma glucose ratio can be useful in the diagnostic work-up of bacterial meningitis, in the central nervous system (CNS), where bacteria in the brain tissue increase glucose metabolism and therefore lower the CSF/plasma ratio [5]. Conversely, hypometabolism is a prominent feature of the pathophysiology of AD, and an increase in the levels of glucose in the interstitial space may therefore be mirrored in the levels of cerebrospinal fluid (CSF) glucose.
Infectious Meningitis and Encephalitis
2022, Neurologic ClinicsCitation Excerpt :CSF should be sent for cell count and differential, protein, glucose, gram stain, and bacterial culture for all patients with suspected CNS infection, with additional studies based on clinical suspicion for specific etiologies. CSF analysis can help differentiate between categories of infectious causes of meningitis (Table 2),41–43 although significant overlap in the CSF profile among pathogens exists.44 CSF lactate may be helpful as an adjunctive assay to identify bacterial meningitis when measured before treatment with antibiotics.45
Using Artificial Intelligence in Diagnostics of Meningitis
2022, IFAC-PapersOnLine
- ☆
No support, grants, nor funding were given to the authors.