Mastering Bacterial Meningitis Guidelines for PLAB 2 OSCE Success

Mastering Acute Bacterial Meningitis Guidelines for PLAB 2 OSCE Success

Bacterial Meningitis is one of the most critical and time-sensitive medical emergencies you will face in clinical practice, and subsequently, in the PLAB 2 OSCE. Failure to recognize the urgency and initiate correct treatment immediately can have devastating consequences for the patient—and for your exam score.

This blog post dissects the essential UK guidelines (aligned with NICE and local protocols) for managing suspected acute bacterial meningitis, ensuring you are prepared to ace this high-stakes scenario.

1. Initial Recognition and Assessment (The Red Flags)

The PLAB 2 station will often present a patient (adult or child) with a rapidly deteriorating state. Immediate recognition is paramount.

Key symptoms to elicit in your history and physical exam:

• Classic Triad: Fever, Headache, and Neck Stiffness (Nuchal rigidity).

• Altered Mental Status: Confusion, drowsiness, or decreased consciousness (GCS score).

• Non-blanching Rash (Purpura/Petechiae): Highly suggestive of meningococcal sepsis/meningitis.

• Focal Neurology: Seizures or new neurological deficits.

Immediate Action: Suspected bacterial meningitis or meningococcal septicaemia demands urgent hospital admission and immediate treatment. The ABCDE approach must be maintained throughout the assessment.

2. Immediate Empirical Treatment: The Golden Hour

In PLAB 2, demonstrating the ability to prioritize life-saving treatment over immediate definitive diagnosis is crucial. Do not wait for investigations if the patient is severely unwell or if transport to hospital is delayed.

The Rule: If meningococcal disease is suspected in the community, or if transport to the hospital is delayed, administer a single dose of intramuscular or intravenous Benzylpenicillin immediately.

In the hospital setting, for suspected bacterial meningitis:

• Antibiotics: Start empirical IV antibiotics immediately (ideally within 1 hour of presentation, often earlier).

  • Adults under 60: IV Cefotaxime (or Ceftriaxone).

  • Adults over 60, immunocompromised, or suspected underlying pathology: IV Cefotaxime/Ceftriaxone PLUS IV Amoxicillin (to cover Listeria monocytogenes).

• Dexamethasone: Give IV Dexamethasone before or with the first dose of antibiotics. This reduces neurological sequelae, especially in pneumococcal meningitis.

PLAB 2 Tip: In your management plan, state clearly: "I will administer IV Cefotaxime immediately after taking blood cultures, along with IV Dexamethasone, and involve the senior team and infectious diseases specialist urgently."

3. Key Investigations and Lumbar Puncture (LP)

Blood cultures are essential and must be taken before administering antibiotics (unless the patient is critically unstable and treatment delay is unacceptable).

Indications for Lumbar Puncture (LP):

LP is necessary for definitive diagnosis (CSF analysis) unless contraindicated.

Absolute Contraindications for LP (Requires a CT scan first):

1. Reduced GCS (GCS < 9 or rapidly falling GCS).

2. New Seizures (within the last week).

3. Focal Neurological Deficit (e.g., limb weakness, pupil abnormality).

4. Papilloedema (suggesting raised ICP).

5. Severe Shock or unstable vital signs.

6. Coagulopathy (including therapeutic anticoagulation).

CT Scan Role: If any of the contraindications are present, a CT scan of the head must be performed before the LP to exclude a mass lesion or significant raised intracranial pressure (ICP).

The Critical Balance: If an LP is contraindicated, you must start empirical antibiotics immediately and proceed to CT. DO NOT DELAY ANTIBIOTICS WAITING FOR THE CT.

4. Communication and Safety Netting in the OSCE

PLAB 2 examiners assess your communication skills, especially in emergencies.

• Explain Urgency: Clearly explain to the patient (or relative) that this is a life-threatening infection requiring immediate, intense treatment in a high-dependency area.

• Involve Seniors: Explicitly state that you are escalating the case to the Registrar/Consultant and involving the Infection Control team.

• Infection Control: Discuss droplet precautions and the need for chemoprophylaxis for close contacts (usually Rifampicin or Ciprofloxacin, guided by local guidelines and public health).

Summary of Management Steps (PLAB 2 Checklist)

1. A-E Assessment: Secure airway and manage shock/sepsis.

2. Blood Tests: FBC, U&Es, LFTs, VBG/ABG, Coagulation screen, Blood cultures, PCR for meningococcus/pneumococcus.

3. Empirical Treatment: IV Antibiotics (Ceftriaxone/Cefotaxime + Amoxicillin if required) + IV Dexamethasone.

4. Assess Need for CT: Check for LP contraindications.

5. Definitive Diagnosis: Perform LP if no contraindications. Send CSF for microscopy, biochemistry, and culture.

6. Escalation & Safety: Involve seniors, plan HDU/ICU transfer, and alert public health for contact tracing and chemoprophylaxis.