Bacterial meningitis at the IMT (Internal Medicine Training) clinical station is answered on a one-hour clock. NICE NG240 asks you to strongly suspect bacterial meningitis in anyone with the red flag combination of fever, headache, neck stiffness and altered level of consciousness or cognition, and to start intravenous antibiotics within 1 hour of arrival in hospital.

Key takeaways

  • NICE NG240 defines a red flag combination for bacterial meningitis: fever, headache, neck stiffness, and altered level of consciousness or cognition, including confusion or delirium.
  • It also says bacterial meningitis can still be strongly suspected without all four, and that fever is less common in older adults.
  • Antibiotics start within 1 hour of arrival in hospital, after blood samples and, where it is safe and will not cause a clinically significant delay, a lumbar puncture.
  • Ceftriaxone is the empirical antibiotic when the organism is unknown, at the highest doses in the BNF, with intravenous amoxicillin added for people with risk factors for Listeria monocytogenes.
  • NICE NG240 says not to routinely perform neuroimaging before lumbar puncture, and lists the specific features that mean you image first and do not tap until they resolve.
  • Intravenous dexamethasone is given to people over 3 months with strongly suspected or confirmed bacterial meningitis, ideally with or before the first antibiotic dose, but never at the cost of delaying antibiotics.

How do you recognise bacterial meningitis in the scenario?

Bacterial meningitis is recognised from the red flag combination NICE NG240 prints: fever, headache, neck stiffness, and altered level of consciousness or cognition including confusion or delirium.

All four together means strongly suspect. However, NICE NG240 says explicitly that bacterial meningitis can still be strongly suspected on clinical assessment in people who do not have all four.

The station is usually written around the gap. Fever is less common in older adults, neck stiffness is harder to identify in people with dementia or arthritis, and altered cognition is easily attributed to alcohol in young adults.

NICE NG240 also lists risk factors that should raise your alert: missed immunisations, reduced or absent spleen function, complement deficiency or acquired inhibition, being a student in large shared accommodation, a family history of meningococcal disease, recent contact or an outbreak, a previous episode, a cerebrospinal fluid leak, and a cochlear implant.

What does the A to E assessment and the first hour look like?

The first hour of bacterial meningitis is blood cultures, intravenous antibiotics and dexamethasone, with a lumbar puncture fitted in only if it is safe and will not delay the antibiotic.

  • Airway and breathing: a reduced conscious level may mean the airway is unprotected, and NICE NG240 lists that as something to treat and stabilise before any lumbar puncture
  • Circulation: shock is also on that list; treat it first, and follow the NICE sepsis guidance alongside, because meningitis and sepsis can occur together
  • Disability: Glasgow Coma Scale score, pupils and focal signs, all of which decide whether imaging comes before the tap
  • Exposure: look for a non-blanching petechial or purpuric rash all over the body, including the conjunctivae, remembering it may be harder to see on brown, black or tanned skin
  • Antibiotics within 1 hour of arrival in hospital, arranged by a senior clinical decision maker who performs the initial assessment

Outside hospital the rule reverses. NICE NG240 says not to delay transfer to give antibiotics, and to give intravenous or intramuscular ceftriaxone or benzylpenicillin only if there is likely to be a clinically significant delay in transfer.

Which investigations does bacterial meningitis need?

NICE NG240 confirms a diagnosis of bacterial meningitis on clinical features, blood test results and lumbar puncture results together, and prints the blood panel in full.

  • Blood culture, white blood cell count including neutrophils, C-reactive protein or procalcitonin if CRP is unavailable, blood glucose, whole-blood diagnostic PCR including meningococcal and pneumococcal, and an HIV test
  • A bacterial throat swab for meningococcal culture, preferably before antibiotics, with the request form marked specifically for meningococcal culture
  • Blood glucose measured immediately before the lumbar puncture, so the cerebrospinal fluid to blood glucose ratio can be calculated
  • Cerebrospinal fluid red and white cell count and cell type, total protein, glucose concentration, Gram stain, culture and sensitivities, and PCR for relevant pathogens
  • NICE NG240 asks that cerebrospinal fluid cell counts, total protein and glucose are available within 4 hours of the lumbar puncture

Say the negative as well. NICE NG240 states that you should not rule out bacterial meningitis on a normal C-reactive protein, procalcitonin or white cell count alone.

When do you image first, and when must you not tap?

NICE NG240 says not to routinely perform neuroimaging before lumbar puncture in suspected bacterial meningitis, which reverses the habit many candidates arrive with.

It then lists exactly when you do image, and says not to perform the lumbar puncture until those factors have resolved.

  • Risk factors for an evolving space-occupying lesion
  • New focal neurological features, including seizures or posturing
  • Abnormal pupillary reactions
  • A Glasgow Coma Scale score of 9 or less, or a progressive and sustained or rapid fall in level of consciousness

The order matters more than the list. NICE NG240 says to take bloods, give antibiotics and stabilise the person before imaging, so the scan never delays treatment.

Separately, do not perform a lumbar puncture where there is extensive or rapidly spreading purpura or infection at the puncture site, and treat and stabilise an unprotected airway, respiratory compromise, shock, uncontrolled seizures or a bleeding risk first.

What is the definitive management of bacterial meningitis?

Definitive management of bacterial meningitis is empirical intravenous ceftriaxone within the hour, dexamethasone alongside it, and then a course length set by the organism once it is known.

  • When the causative organism is not identified, give ceftriaxone at the highest doses recommended by the BNF, or consider cefotaxime if ceftriaxone is contraindicated
  • Add intravenous amoxicillin to the ceftriaxone or cefotaxime for people with risk factors for Listeria monocytogenes
  • NICE NG240 says not to routinely give intravenous aciclovir unless herpes simplex encephalitis is strongly suspected
  • If the cerebrospinal fluid suggests bacterial meningitis but blood culture and whole-blood PCR are negative, continue antibiotics for 10 days
  • Once the organism is known: 10 days for Streptococcus pneumoniae, 7 days for Haemophilus influenzae type b with 10 if not recovered, 14 days for group B streptococcus, 21 days of amoxicillin or ampicillin for Listeria monocytogenes, and 5 days for Neisseria meningitidis

Dexamethasone has its own set of rules in bacterial meningitis, and they are a favourite closed question. Give intravenous dexamethasone to people over 3 months with strongly suspected or confirmed bacterial meningitis.

  • Give the first dose with or before the first dose of antibiotics if possible, and never delay antibiotics to wait for it
  • If dexamethasone is delayed by less than 12 hours after antibiotics start, give it as soon as possible; beyond 12 hours, seek infection specialist advice on whether it still helps
  • Continue dexamethasone if the organism is pneumococcus or Haemophilus influenzae type b, and stop it for all other organisms
  • Do not routinely give corticosteroids in meningococcal disease, though low-dose replacement corticosteroids are considered in meningococcal septic shock not responding to high-dose vasoactive agents

NICE NG240 also says not to routinely restrict fluid intake below routine maintenance needs, and not to use glycerol at all in the management of bacterial meningitis.

When and to whom do you escalate bacterial meningitis?

Escalate bacterial meningitis to a senior clinical decision maker at the front door, because NICE NG240 makes that person responsible for ensuring antibiotics start within 1 hour of arrival.

Get infection specialist advice for all cases of bacterial meningitis, and particularly for people who have recently travelled outside the UK or are colonised with cephalosporin-resistant organisms.

Involve critical care urgently where there are signs of raised intracranial pressure and concern about brain herniation, since that is the only situation in which NICE NG240 considers an osmotic agent, and glycerol is excluded even then.

Notify public health, and remember the follow-up: NICE NG240 asks for an audiological assessment within 4 weeks of the person being well enough for testing, and preferably before discharge.

How do you hand over bacterial meningitis in one minute?

The bacterial meningitis handover uses SBAR and leads with the time antibiotics were given, because the receiving team needs to know whether the one-hour standard was met.

Situation: a 19 year old student with fever, headache, neck stiffness and new confusion for six hours, with a non-blanching rash on the shins. Background: lives in halls, immunisation history uncertain.

Assessment: strongly suspected bacterial meningitis with meningococcal disease, GCS 14, blood pressure 96 over 58, lactate 3.2. Recommendation: cultures and PCR sent, ceftriaxone and dexamethasone given 25 minutes after arrival, lumbar puncture deferred while shock is corrected, please review for critical care now.

What does the panel listen for in a bacterial meningitis answer?

The panel listens for the red flag combination named as four features, antibiotics within 1 hour, the reversal of the old habit of scanning everyone before a lumbar puncture, and dexamethasone given without delaying antibiotics.

In practice they also mark whether you say that a normal C-reactive protein does not exclude the diagnosis, because that is the sentence that keeps a patient alive at three in the morning. The internalmedicineinterview bank of 361 questions across 56 scenarios, with AI-marked spoken practice, drills exactly those lines.

What are the common mistakes in a bacterial meningitis station?

  • Delaying antibiotics until after a CT head that the guideline says is not routinely needed
  • Delaying antibiotics to complete a lumbar puncture, when the tap is only done first if it is safe and causes no clinically significant delay
  • Delaying antibiotics to give dexamethasone, when the guideline says the opposite
  • Requiring all four red flag features before treating, when the guideline says bacterial meningitis can still be strongly suspected without them
  • Being reassured by a normal C-reactive protein, procalcitonin or white cell count
  • Forgetting the HIV test, the throat swab for meningococcal culture, and the audiological assessment within 4 weeks

How this comes up at the IMT interview

Bacterial meningitis maps onto all three parts of the IMT clinical station. Investigations and diagnosis is the blood panel, the imaging decision and the lumbar puncture; management is ceftriaxone within the hour with dexamethasone and an amoxicillin decision; and communication is explaining to a frightened student and their family why treatment started before any test came back.

The handover minute is where the antibiotic time, the conscious level and the reason the lumbar puncture was deferred have to be said in order, with an explicit ask and a time for review.