Brain herniation and the use of CT-scanning in acute bacterial meningitis
Abstract number: P1226
Meyer C.N., Augustesen S.
Objectives: The purpose of our study was to evaluate the circumstances surrounding brain herniation among patients with verified acute bacterial meningitis, to analyse the use of early (before lumbar puncture) head CT-scanning, and to evaluate whether the guidelines concerning early initiation of therapy (before CT-scanning) were followed.
Methods: On a national basis, unselected patients with microbiologically and clinically verified acute bacterial meningitis from 47 hospitals during 2 years (n = 320) were included. Survival data and clinical data from the medical records were evaluated retrospectively. Two-tailed p < 0.05 indicated a significant difference.
Results: Among 320 patients with acute bacterial meningitis, a total of 161 CT-scans were performed, 57 CT scans were done before lumbar puncture, and initial considerations of bacterial meningitis were documented in 20 of these. In the other 37 cases, only other diagnostic considerations than meningitis were documented. Five of 320 patients (1.6%) had brain herniation. Brain herniation occurred after spinal tap in 2 patients with no signs of brain shift on the recent CT-scan, and in 3 patients who had lumbar puncture done before the accomplishment of a CT scan which showed signs of incarceration in 2 cases. In 4 of the 5 patients, cerebral oedema was described, and 1 CT scan was described as normal. Though, cerebral oedema was described in 14 other patient without brain herniation (specificity /52=0.73). In the 20 early CT patients suspected of meningitis, antibiotic therapy was given before CT-scan or lumbar puncture in 30% (6/20). Median time from admission to first relevant antibiotic dose given among the early CT scanned patients (225 minutes) differed significantly from the never scanned patients (75 minutes, p < 0.001).
Conclusions: Brain herniation could not safely be predicted by CT-scanning alone, as the sensitivity was rather low (2/5). The finding of cerebral oedema may be seen as a radiological red flag for brain herniation with a rather low specificity (0.73). When bacterial meningitis was suspected, the clinical guidelines were not followed satisfactorily concerning swiftly administration of therapy without awaiting the result of the CT scan.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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