Meningitis

Author: Charlotte Davies / Editor: Nikki Abela / Codes: / Published: 10/04/2018

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You pick up the next patient to be seen. It’s a 25-year-old who has neck stiffness, and a headache, and a sore throat. The GP has sent them in as a possible meningitis patient. Where do you go from there?

This is a common scenario that may fill you with dread. It is easy to treat all these patients as meningitis, but doing that often gives you more questions than answers, and we hope to answer some of them here. You might decide the neck stiffness is all due to the tonsillitis, but that would also be a brave decision to make!

So, what is meningitis?

Meningitis is anything that causes an inflammation of the meninges. Meningococcal septicaemia is when there is overwhelming sepsis in association with meningeal irritation. Differentiating between these two different types will help us to know which antibiotics the patient needs!

Clinical Presentation

The classic triad of fever, headache, and neck stiffness (70% sensitivity) only occurs in less than 50% of patients. Changes in mental state are relatively sensitive and tend to occur more often in bacterial than viral meningitis.

60% of patients will have a petechial rash, but some may have an erythematous rash. A petechial rash in a patient with suspected meningitis is a late sign, so don’t rely on it to make a diagnosis.

Kernig’s test is positive if there is pain or resistance in the lower back or posterior thigh when the knee is extended while the hip is flexed to 90 . It is like many things, a useful rule in, but not a rule out.

Brudzinski’s sign is not specific for meningococcal meningitis. You can elicit the sign by passive flexion of the neck, resulting in flexion of the hips and knees if positive.

Other signs to look for are suggestions that meningitis isn’t the sole presenting complaint. Encephalitis has a similar presentation to meningitis, but confusion and drowsiness tend to be more prominent – if in doubt, treat as meningitis.

A suddenly worsening headache, followed by emerging signs of meningism, is often associated with rupture of a cerebral abscess. This is associated with a high mortality: up to 80%. Emergency surgery is indicated.

Management of Suspected Meningitis in the Emergency Department

1. Recognise

2. Investigate Take extra two EDTA (purple) tubes for meningococcal or pneumococcal DNA using PCR. Also take blood cultures. Do not wait for the results before commencing treatment. It is difficult to differentiate viral meningitis from bacterial meningitis on clinical grounds alone so an LP is indicated.

3. Treat

  1. Sepsis 6 with antibiotics as per trust antimicrobial guideline – (Ceftriaxone 2g + amoxicillin 2g if >50years or immunocompromised)
  2. Dexamethasone 10mg IV
  3. Aciclovir if features of encephalitis (fluctuating consciousness, motor or sensory deficits, altered behaviour and personality changes, and speech or movement disorders). There are currently no treatments with a proven benefit for the common causes of viral meningitis, although acyclovir is often used, despite it being nephrotoxic and lowering seizure threshold. It does reduce the mortality of encephalitis from 70% to less than 30%. Treatment should be supportive.
  4. CT would be indicated if there are focal neurological signs, papilloedema, controlled or uncontrolled seizures, GCS <12 or diagnostic uncertainty. Depending on your departmental pathways, the medical team may ask the ED team to arrange a CT, but completion of this should not delay their review of the patient.
  5. Meningitis, even viral, is reportable to the local health protection team who will also coordinate antibiotic prophylaxis for close contacts:
  6. Isolate as per your trust policy. A patient with known or suspected meningococcal meningitis should be isolated in a single room with droplet precautions for 24 hours from the time that effective antibiotic treatment has been started. Staff caring for the patient should observe the standard infection control precautions and wear FFP3 masks, gloves and aprons. Those performing procedures that may generate aerosols, for example suctioning, intubation or inserting an airway, should wear properly fitted FFP3 masks and eye protection.

When a patient recovers from bacterial meningitis, headache, fatigue, and difficulty with coordination, concentration, and memory may persist for several months.

References

  1. Journal Of Infection Algorithm and PDF.
  2. Encephalitis
  3. RCEM Learning Module
  4. BMJ Learning Module 1 and 2.

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