Lumbar Puncture Performed Promptly or After Neuroimaging in Acute Bacterial Meningitis in Adults: A Prospective National Cohort Study Evaluating Different Guidelines.

BACKGROUND: Early treatment is pivotal for favorable outcome in acute bacterial meningitis (ABM). Lumbar puncture (LP) is the diagnostic key. The aim was to evaluate the effect on outcome of adherence to European Society of Clinical Microbiology and Infectious Diseases (ESCMID), Infectious Diseases Society of America (IDSA), and Swedish guidelines regarding neuroimaging before LP.

METHODS: The cohort comprised 815 adult ABM patients in Sweden registered prospectively between 2008 and 2015. Primary endpoint was in-hospital mortality and secondary endpoint was favorable outcome at 2-6 months of follow-up.

RESULTS: Indications for neuroimaging before LP existed in 7%, 32%, and 65% according to Swedish, ESCMID, and IDSA guidelines, respectively. The adjusted odds ratio (aOR) was 0.48 (95% confidence interval [CI], .26-.89) for mortality and 1.52 (95% CI, 1.08-2.12) for favorable outcome if Swedish guidelines were followed. ESCMID guideline adherence resulted in aOR of 0.68 (95% CI, .38-1.23) for mortality and 1.05 (95% CI, .75-1.47) for favorable outcome. Following IDSA recommendations resulted in aOR of 1.09 (95% CI, .61-1.95) for mortality and 0.59 (95% CI, .42-.82) for favorable outcome. Performing prompt vs neuroimaging-preceded LP was associated with aOR of 0.38 (95% CI, .18-.77) for mortality and 2.11 (95% CI, 1.47-3.00) for favorable outcome. The beneficial effect of prompt LP was observed regardless of mental status and immunosuppression.

CONCLUSIONS: Adherence to Swedish guidelines in ABM is associated with decreased mortality and increased favorable outcome in contrast to adherence to ESCMID or IDSA recommendations. Our findings support that impaired mental status and immunocompromised state should not be considered indications for neuroimaging before LP in patients with suspected ABM.