Early lumbar puncture in adult bacterial meningitis--rationale for revised guidelines.

Current international guidelines recommend cerebral computerized tomography (CT) before lumbar puncture (LP) in many adults with suspected acute bacterial meningitis (ABM), due to concern about LP-induced cerebral herniation. Despite guideline emphasis on early treatment based on symptoms, performing CT prior to LP implies a risk of delayed ABM treatment, which may be associated with a fatal outcome. Firm evidence for LP-induced herniation in adult ABM is absent and brain CT cannot discard herniation. Thus, the recommendation to perform CT before LP may contribute to an avoidable delay of LP and ABM treatment. The inappropriate use of the diagnostic treatment sequence of brain CT scan, followed by LP, followed by antibiotics and corticosteroids should be avoided in adults with suspected ABM by omitting needless contraindications for LP, thus eliminating an unnecessary fear of immediate LP. Revised Swedish guidelines regarding early LP are presented, and the background documentation and reasons for omitting impaired consciousness, new onset seizures, and immunocompromised state as contraindications to LP are discussed.