Antibiotic timing in patients with suspected bacterial meningitis

In patients with suspected bacterial meningitis, collecting samples before antibiotics are administered maximises the chance of isolating the pathogen; however, prompt treatment with antibiotics is important because it reduces morbidity and mortality. Consequently, if there is likely to be a significant delay in performing investigations (including lumbar puncture), start empirical antibiotics as soon as possible, ideally within 1 hour of presentation to hospital.

If lumbar puncture has been performed and clinical suspicion of bacterial meningitis is high, start antibiotics while waiting for results, including microbial susceptibility.

If a lumbar puncture has not been performed because the patient has relative contraindications to lumbar puncture, and clinical suspicion of bacterial meningitis is high, start antibiotics while waiting for lumbar puncture or scans to be performed.

For empirical antibiotic regimens for suspected bacterial meningitis, see:

• Meningitis in adults and children 2 months or older
• Meningitis in neonates and children younger than 2 months.