Background: ABM is a diagnosis with high morbidity and mortality. Early antimicrobial and corticosteroid therapy is beneficial. Current practice tends to defer LP prior to imaging when there is potential risk of herniation. Sweden’s guidelines for getting a CT scan prior to LP differ substantially from the Infectious Disease Society of America (IDSA), which recommends obtaining CT in patients with immunocompromised state, history of CNS disease, or impaired mental status.
Study design: Prospective cohort study.
Setting: 815 adult patients (older than 16 years old) in Sweden with confirmed acute bacterial meningitis.
Synopsis: The authors looked at adherence to guidelines for when to obtain a CT prior to LP, as well as compared mortality and neurologic outcomes when an LP was performed promptly versus when delayed for prior neuroimaging. CT neuroimaging was required in much smaller populations under Swedish guidelines (7%), compared with IDSA (65%), with improved mortality and outcomes in patients managed with the Swedish guidelines. Mortality was lower in patients who had a prompt LP than for those who got CT prior to the LP (4% vs. 10%). This mortality benefit was seen even in patients with immunocompromised state or altered mental status, confirming that earlier administration of appropriate therapy is associated with lower mortality. A major limitation is that the study included patients with confirmed meningitis rather than more clinically relevant cases of suspected bacterial meningitis.
Bottom line: Patients with suspected bacterial meningitis should have appropriate antimicrobial and corticosteroid therapy started as soon as possible, regardless of the decision to obtain CT scan prior to performing lumbar puncture.
Citation: Glimaker M et al. Lumbar puncture performed promptly or after neuroimaging in acute bacterial meningitis in adults: a prospective national cohort study evaluating different guidelines. Clin Infect Dis. 2017 Sep 9.(epub ahead of print).
Dr. Maleque is assistant professor of medicine in the division of hospital medicine, Emory University, Atlanta.