Bacterial Meningitis: Empiric Treatment Review

Bacterial meningitis is a medical emergency, and exam questions focus on one big idea: treat quickly. Many questions ask what to do first, which antibiotics to start and how to interpret cerebrospinal fluid results. These points are the core of the topic.

Recognize the syndrome

Typical features are fever, headache, neck stiffness, photophobia and altered mental state. Some patients have a petechial rash, suggesting meningococcal disease, or signs of raised intracranial pressure. Infants and older adults may present subtly.

Step 1: Act quickly

Take blood cultures and start empirical antibiotics without delay. If a lumbar puncture cannot be done promptly, because of the need for a scan or instability, do not wait to give antibiotics.

Step 2: When to scan first

Consider CT before lumbar puncture if there are signs of raised intracranial pressure or a mass lesion, such as focal neurological deficits, papilledema, a seizure, severe impairment of consciousness or immunocompromise. Antibiotics come first if the scan causes any delay.

Step 3: Empirical antibiotics

• A third-generation cephalosporin such as ceftriaxone or cefotaxime plus vancomycin for most adults
• Add ampicillin when Listeria is a concern, for example in older adults, pregnancy and immunocompromised patients

Tailor the treatment once the organism and sensitivities are known. In neonates, the usual organisms and the antibiotics differ.

Step 4: Dexamethasone

Give dexamethasone before or with the first antibiotic dose in suspected bacterial meningitis in adults, because it reduces neurological complications, particularly in pneumococcal disease. Stop it if another diagnosis is established.

CSF patterns

• Bacterial: high neutrophil count, high protein, low glucose
• Viral: lymphocytes, mildly raised protein, normal glucose
• Tuberculous: lymphocytes, very high protein, low glucose

Common organisms

Streptococcus pneumoniae and Neisseria meningitidis in adults. Group B streptococcus, Escherichia coli and Listeria in neonates.

Prophylaxis and complications

Close contacts of meningococcal disease receive antibiotic prophylaxis according to local guidance, and vaccination reduces risk. Complications include hearing loss, seizures, hydrocephalus and cognitive effects.

A classic exam pattern

A patient with fever, neck stiffness and confusion arrives and a CT will take an hour. The best answer is to give blood cultures, dexamethasone and antibiotics immediately and not to wait for imaging.

Study tips

• Memorize the antibiotic combination and who needs ampicillin
• Learn the three CSF patterns
• Review each wrong answer for the timing clue

This article is for exam revision and does not replace current clinical guidelines. Test your knowledge in the Namazj free trial.