Meningitis

Question 1

What is meningitis

Answer 1

Infection of the meninges in the brain or spinal cord, that is most commonly viral or bacterial in origin, but may also be fungal, parasitic or due to non-infectious causes

Question 2

What demographics does it happen to most commonly?

Answer 2

In children, most often <1 years of age
Median age in adults is 43 years

Question 3

What are the risk factors of meningitis

Answer 3

. Immunocompromised
. Crowded living space
. Otitis media (infection and inflammation of the middle ear- causes fluid build up, pain, fever)
. Sinusitis- causes facial pain/ pressure, thick nasal discharge
. CSF leak after head trauma or neurosurgery
. Sepsis

Question 4

Bacterial meningitis: which bacteria causes meningitis in neonates

Answer 4

GEL
Group B streptococcus (lives in the rectum and Vagina)
E. coli
Listeria monocytogenes

Question 5

Which bacteria cause meningitis in children

Answer 5

. Neisseria meningitidis- gram -ve diplococci (also cause petechial non-blanching rash)
- Haemophilus influenzae → gram -ve coccobacilli
- Streptococcus pneumoniae → gram +ve diplococci

Question 6

What bacteria causes meningitis in elderly

Answer 6

Streptococcus pneumoniae

Question 7

Which bacteria cause meningitis in the immunocompromised

Answer 7

Listeria monocytogenes

Question 8

What virus cause it (more common)

Answer 8

Enterovirus (poliovirus, coxsackie A)- most common
HSV
VZV
Mumps

Question 9

What are the clinical features of meningitis

Answer 9

• Fever
• Headache
• Neck stiffness
• Photophobia
• Irritability
• Nausea and vomiting
• Altered mental status
• Seizures
• Deafness

Question 10

What signs on examination do you see

Answer 10

Kernig sign- inability to straighten leg when hip is flexed to 90o
Brudzinski sign- forced flexion of neck elicits a reflex flexion of hips and knee

Question 11

What sign do you see in meningococcal meningitis

Answer 11

Non-blanching rash

Question 12

What are clinical features of meningitis in neonates (newborn infant from birth to 28 days)

Answer 12

• No classic triad of fever, headache, neck stiffness
• lethargy
• irritability
• poor appetite
• vomiting
• fontanelle bulging (increased pressure inside skill due to fluid build up or brain swelling from infection)
• seizures

Question 13

What main analysis is needed

Answer 13

Lumbar puncture for csf analysis (only if no signs of raised ICP)

Question 14

What would bacterial infected CSf show

Answer 14

• Cloudy
• High neutrophils (polymorphonuclear cells)
• High protein
• Low glucose (typically less than half of serum glucose)
  Less pus but reproduce very quickly

Question 15

What would viral infected csf show

Answer 15

• Clear
• High lymphocytes (mononuclear cells)
• High protein
  Normal glucose (would be low in mumps, hsv)
  Normal opening pressure

Question 16

What would TB infected CSF show?

Answer 16

• Slightly cloudy/fibrin web
• High lymphocytes
• High protein
• Low glucose
• High opening pressure

Fibrinogen doesn’t normally occur in CSF- hence derangement of passage of proteins from the blood into the csf can indicate neurological disease

Question 17

What scans do you do

Answer 17

CT head before lumbar puncture- if increased ICP is suspected to assess for risk of brain herniation due to lumbar puncture

Question 18

What other investigation needs to be done before starting antibiotics

Answer 18

2 sets of blood culture

Question 19

In primary care, what should be done immediately when bacterial meningitis suspected

Answer 19

For suspected meningococcal disease- IV or IM benzylpenicillin (narrow spectrum beta lactam antibiotics for bacterial disease) should be administered- then send to hospital

However if they have suspected bacterial meningitis without non blanching rash- directly to secondary care without giving parenteral antibiotics.
Classical bacterial meningeal pathogens may potentially enter the CSF bypenetrating the BBB of cerebral microvessels and entering the extracellular fluid of the brain
, which is continuous with the CSF

Question 20

In hospital when should LO be delayed

Answer 20

• Sepsis/rapidly evolving rash signs
• Severe resp/cardiac compromise
• Significant bleeding risk
• Signs of ICP e.g. papilloedema, neurological signs, seizures, GCS ≤12

Question 21

What would you do if the LP has to be delayed

Answer 21

Start antibiotics- ceftriaxone/ cefotaxime if <50 and add amoxicillin if >50

Can give IV dexamethasone (long acting corticosteroid) to reduce risk of complications

Question 22

What do you give if raised ICP

Answer 22

Secure airway + high flow oxygen
Bloods and blood culture from IV access
IV dexamethasone
IV antibiotics (as above)
Do CT

Question 23

What should we do if LP isn’t contraindicated

Answer 23

Take blood and blood culture
- Do LP
- IV Abx → cefotaxime/ceftriaxone if <50 and add amoxicillin if >50 in age
- IV dexamethasone → AVOID in meningococcal septicaemia

CT normally not done if no signs of ICP

Question 24

How would you treat individuals with viral meningitis

Answer 24

• Supportive measures
• Usually self-limiting
• Maybe anti-virals (aciclovir if HSV suspected)

Question 25

What’s given to close contact (When someone has been in close contact with a person who has a serious bacterial infection such as meningococcal disease)?

Answer 25

prophylactic antibiotics → oral ciprofloxacin or rifampicin

Question 26

What are the complications of meningitis

Answer 26

- Deafness (sensorineural hearing loss - most common complication) - Septicaemia - Shock - Disseminated Intravascular coagulation - Cerebral oedema - Renal failure - Cranial nerve lesion

Question 27

Describe the prognosis

Answer 27

- Bacterial meningitis is fatal if untreated - Viral meningitis resolves spontaneously in majority of cases

Question 28

Pathology of meningitis

Answer 28

Bacteria travel to brain via bloodstream and multiply in the CSF within the SAS triggering an inflammatory cascades Infection causes: increased permeability of the blood-brain barrier, immune cell infiltration (leukocytes) into the subarachnoid space release of inflammatory mediators, causing cerebral oedema, nerve damage and potential brain parenchymal involvement

Question 29

Complication of sepsis in context of meningitis

Answer 29

. Hypotension needing fluids + vasopressors . Disseminated intravascular coagulation- leads to bleeding + microthrombi- tissue necrosis . Purpura fulminans- rapidly progressing purpurin rash (dark purple skin lesions). Skin necrosis due to DIC and vascular. May lead to amputation or severe scarring

Question 30

Why do you need vbg profile

Answer 30

Meningitis—especially meningococcal—can rapidly cause: Lactic acidosis → indicates tissue hypoperfusion Metabolic acidosis → suggests severe sepsis A VBG gives a quick lactate level, which is a marker of severity

Question 31

How can you identify TB

Answer 31

Detect bacteria 1. Fluorescent test 2. ZN stain (ziehl- neelsen stain)

Question 32

When will you withhold benzylpenicillin

Answer 32

People who has a clear history of anaphylaxis after a previous dose A rash of a following penicillin is not a contraindication

Question 33

What information would you give the anaesthetist for the LO undergoing general anaesthesia

Answer 33

Allergies medication- some blood thinners means can’t do LP Past history- you don´t want to anaesthetise them if they have a complex condition Last meal Events

Question 34

What does group A streptococcus involved in

Answer 34

Not meningitis Cause rheumatic heart disease