What is the initial medication to administer to a patient with intermittent fever, neck stiffness, and seizures in the emergency department, with a negative computed tomography (CT) head scan?

Initial Management of Suspected Bacterial Meningitis with Seizures

The first medication to administer to a patient with intermittent fever, neck stiffness, and seizures in the emergency department with a negative CT head is intravenous ceftriaxone plus vancomycin, followed immediately by dexamethasone if not already given.

Immediate Management Algorithm

1. Control seizures first:

   • Administer benzodiazepines (lorazepam or diazepam) to stop ongoing seizures
   • If seizures persist, consider phenytoin or levetiracetam as second-line agents

2. Empiric antimicrobial therapy (within 30 minutes of presentation):

   • Ceftriaxone 2g IV (covers most common bacterial meningitis pathogens)
   • PLUS Vancomycin 15-20 mg/kg IV (for potential resistant pneumococci)
   • Start antibiotics IMMEDIATELY after blood cultures but BEFORE lumbar puncture if LP will be delayed

3. Adjunctive corticosteroid therapy:

   • Dexamethasone 10 mg IV (ideally before or with first dose of antibiotics)
   • Continue q6h for 4 days if bacterial meningitis is confirmed

4. Fluid resuscitation:

   • Initial bolus of 500 mL crystalloid if signs of hemodynamic instability 1
   • Monitor response and continue guided by clinical parameters

Rationale for Management

Antimicrobial Selection

The clinical presentation strongly suggests bacterial meningitis. The UK Joint Specialist Societies guideline recommends immediate empiric antibiotics for suspected bacterial meningitis 2. The combination of ceftriaxone and vancomycin provides coverage against the most common pathogens including resistant pneumococci.

Timing of Antibiotics

Antibiotics should be administered without delay after blood cultures are taken, and should not be delayed if cultures cannot be obtained quickly 1. Any delay in antimicrobial therapy can significantly increase mortality and morbidity.

Role of Dexamethasone

Dexamethasone reduces mortality and neurological sequelae in bacterial meningitis when given before or with the first dose of antibiotics 3. The recommended dose is 10 mg IV, followed by 4 mg every 6 hours for 4 days 3.

Seizure Management

Seizures in the context of meningitis indicate severe disease and require immediate control to prevent further neurological damage. Benzodiazepines are the first-line agents for acute seizure management.

Further Diagnostic Steps

After initial stabilization and treatment:

1. Lumbar Puncture:

   • Perform as soon as possible if no contraindications exist
   • CT scan was negative, so LP can proceed safely
   • Send CSF for cell count, glucose, protein, Gram stain, culture, and PCR if available

2. Monitor for increased intracranial pressure:

   • Document opening pressure during LP if possible
   • If CSF pressure ≥25 cm of CSF, reduce by 50% through CSF drainage 2
   • Repeat LP daily if pressure remains elevated and symptoms persist 2

Common Pitfalls to Avoid

1. Delaying antibiotics while waiting for diagnostic tests - this increases mortality

2. Omitting vancomycin from initial therapy - penicillin and cephalosporin resistance is increasingly common in pneumococci 4

3. Administering dexamethasone after antibiotics - reduces its effectiveness in preventing neurological sequelae

4. Fluid restriction in an attempt to reduce cerebral edema - this is not recommended and may worsen outcomes 1

5. Relying on classic signs like Kernig's and Brudzinski's signs, which are unreliable for diagnosis 2

This approach prioritizes rapid treatment of the most likely life-threatening condition while ensuring appropriate diagnostic steps are taken to confirm the diagnosis and adjust therapy as needed.