Prior to the revised Swedish lumbar puncture guideline, a CT scan was often performed prior to lumbar puncture when acute bacterial meningitis was suspected. Taking the time to perform a CT scan of the head before lumbar puncture delays treatment and results in an unfavorable outcome. The Swedish guidelines were amended to omit altered mental status as a contraindication for lumbar puncture without a previous CT scan. A retrospective review of the Swedish registry was conducted to evaluate patient outcomes after the guideline was revised.
Over 700 cases of community-acquired adult bacterial meningitis were reviewed. Foregoing a CT scan before lumbar puncture resulted in patients receiving treatment 1.6 hours sooner. By following the new guidelines, mortality was decreased from 11.7% to 6.9% and risk of neurological sequelae also decreased from 49% to 38%.
The amendment of the Swedish guidelines to remove impaired mental status as a contraindication for lumbar punctures without prior CT scan led to more favorable outcomes. International guidelines on lumbar puncture would do well to consider this revision.