Adult bacterial meningitis: earlier treatment and improved outcome following guideline revision promoting prompt lumbar puncture.

BACKGROUND In suspected acute bacterial meningitis (ABM), cerebral computerized tomography (CT) is recommended before lumbar puncture (LP) if mental impairment. Despite guideline emphasis on early treatment, performing CT prior to LP implies a risk of delayed treatment and unfavorable outcome. Therefore, Swedish guidelines were revised in 2009, deleting impaired mental status as a contraindication for LP without prior CT scan. The aim of the present study was to evaluate the guideline revision. METHODS The Swedish quality registry for community-acquired ABM was analyzed retrospectively. Door-to-antibiotic time and outcome were compared among patients treated 2005-2009 (n=394) and 2010-2012 (n=318). The effect of different LP-CT sequences was analyzed during 2008-2012. RESULTS Adequate treatment was started 1.2 hours earlier, and significantly more patients were treated <2 hours from admission 2010-2012 than 2005-2009. Compared with CT before LP, immediate LP resulted in 1.6 hours earlier treatment, significant increase in door-to-antibiotic times of <1 and <2 hours, and a favorable outcome. In 2010-2012, mortality was lower (6.9% vs 11.7%) and the risk of sequelae at follow-up decreased (38% vs 49%) in comparison with 2005-2009. Treatment delay resulted in a significantly increased risk for fatal outcome, with a relative increase in mortality of 12.6% per hour of delay. CONCLUSIONS The deletion of impaired mental status as contraindication for prompt LP and LP without prior CT scan are associated with significantly earlier treatment and a favorable outcome. A revision of current international guidelines should be considered.