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Cerebral microdialysis for detection of bacterial meningitis in aneurysmal subarachnoid hemorrhage patients: a cohort
Florian Schlenk1, Katja Frieler, Alexandra Nagel
1Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany. florian.schlenk@charite.de
Introduction:
Bacterial meningitis (BM) is a severe complication in patients with aneurysmal subarachnoid haemorrhage (SAH). Clinical signs of meningitis are often masked by SAH-related symptoms, and routine cerebrospinal fluid (CSF) analysis fails to indicate BM. Microdialysis (MD) is a technique for monitoring cerebral metabolism in patients with SAH. A cohort study was performed to investigate the value of MD for the diagnosis of BM.
Methods:
Retrospectively, 167 patients with SAH in an ongoing investigation on cerebral metabolism monitored by MD were analysed for the presence of BM and related MD changes. Diagnosis of BM was based on microbiological CSF culture or clinical symptoms responding to antibiotic treatment, combined with an increased CSF cell count and/or fever. Levels of MD parameters before and after diagnosis of BM were analysed and compared with the spontaneous course in controls.
Results:
BM developed in 20 patients, of which 12 underwent MD monitoring at the time of diagnosis. A control group was formed using 147 patients with SAH not developing meningitis. On the day BM was diagnosed, cerebral glucose was lower compared with the value three days before (p = 0.012), and the extent of decrease was significantly higher than in controls (p = 0.044). A decrease in cerebral glucose by 1 mmol/L combined with the presence of fever >or= 38 degrees C indicated BM with a sensitivity of 69% and a specificity of 80%. CSF chemistry failed to indicate BM, but the cell count increased during the days before diagnosis (p < 0.05).
Conclusions:
A decrease in MD glucose combined with the presence of fever detected BM with acceptable sensitivity and specificity, while CSF chemistry failed to indicate BM. In patients with SAH where CSF cell count is not available or helpful, MD might serve as an adjunct criterion for early diagnosis of BM.
Insights
Microdialysis (MD) can help diagnose bacterial meningitis (BM) in subarachnoid hemorrhage (SAH) patients. A drop in cerebral glucose levels, combined with fever, shows promise for early BM detection when CSF analysis is inconclusive.
Area of Science:
- Neuroscience
- Infectious Diseases
- Medical Technology
Background:
- Bacterial meningitis (BM) is a serious complication following aneurysmal subarachnoid hemorrhage (SAH).
- Standard cerebrospinal fluid (CSF) analysis often fails to detect BM due to overlapping symptoms with SAH.
- Cerebral microdialysis (MD) monitors brain metabolism and may offer diagnostic value in SAH patients.
Purpose of the Study:
- To investigate the utility of cerebral microdialysis (MD) for diagnosing bacterial meningitis (BM) in patients with subarachnoid hemorrhage (SAH).
- To compare the diagnostic performance of MD parameters with traditional CSF analysis for BM in SAH.
Main Methods:
- A retrospective analysis of 167 SAH patients undergoing MD monitoring was conducted.
- BM diagnosis was confirmed via CSF culture or clinical response to antibiotics with elevated CSF cell count/fever.
- MD parameters were analyzed before and after BM diagnosis and compared to controls without BM.
Main Results:
- BM developed in 20 patients; 12 were monitored by MD at diagnosis.
- A significant decrease in cerebral glucose was observed on the day of BM diagnosis compared to baseline and controls.
- A decrease in cerebral glucose (1 mmol/L) plus fever (>=38°C) showed 69% sensitivity and 80% specificity for BM.
Conclusions:
- Cerebral microdialysis (MD) glucose decrease combined with fever can aid in diagnosing BM in SAH patients.
- CSF chemistry was not indicative of BM, though CSF cell counts increased prior to diagnosis.
- MD serves as a valuable adjunct for early BM diagnosis in SAH patients, especially when CSF analysis is unhelpful.
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