meningitis Flashcards
1
Q
What is meningitis?
A
inflammation of the membranes covering the brain and spinal cord (meninges)
2
Q
causes of meningitis
A
– Viruses
– Bacteria
– Fungi
3
Q
Inc risk of meningitis after what?
A
head trauma
in presence of ventriculo-peritoneal shunts (brian surgery, putting in shunts)
4
Q
layers of meninges
A
dura matter (out)
arachniod (middle)
pia matter (inner)
5
Q
most common cause of bacterial meningitis
A
Neisseria meningitidis
(gram negative diplococci)
6
Q
Neisseria meningitidis
A
- 13 types (serogroups)
- characterised by surface structures in the capsule and outer cell membrane
- 5 responsible for most cases of invasive disease
- A, B, C, Y and W-135
7
Q
other bacterial causes
A
- S. Pneumoniae
(G+ve cocci) - H. influenzae type B
(G-ve rods)
8
Q
What does causastive agent depend on?
A
age of pt
9
Q
viral causes of meningitis
A
- less severe than bacterial meningitis
- usually resolves without Tx
- caused by viruses that live in the intestines
- Enteroviruses (most common)
- mumps and measles viruses and herpes viruses
- poor hygiene may increase the risk of transmission
- not all people exposed to the virus will develop meningitis
10
Q
fungal causes of meningitis
A
- life threatening
- rare disease
- usually in pts with compromised immune fxn
- slow progression
- difficult to diagnose and treat
- Cryptococcus, Candida
11
Q
non-infective causes of meningitis
A
- complication of head injury, brain surgery, some cancers
- sometimes drugs
12
Q
greatest age risk for meningitis
A
< 5 years
13
Q
common bacterial pathogens in newborns
A
- Group B streptococci
- E coli
- Listeria monocytogenes
14
Q
common bacterial pathogens in infants
A
- Neisseria meningitidis
- Haemophilus influenzae
- Streptococcus pneumoniae
15
Q
common bacterial pathogens in children
A
- N meningitidis
- S pneumoniae
16
Q
common bacterial pathogens in adults
A
- S pneumoniae
- N meningitidis
- Mycobacteria
17
Q
most common cause in Africa
A
Group A meningococcus
18
Q
vaccine for what casue of meningitis
A
Meningitis A
(Group A meningococcus)
19
Q
Neisseria meningitidis - spread
A
- normally in nasopharynx
- transmitted by droplets/ secretions from the URTI
- spread by close contact (not highly transmissible)
- epidemics in crowded environments
20
Q
RF
A
- infants & young children
- community settings - inc close contact
- asplenia
- immunocompromised
- exposure to active/passive tobacco smoke
- elderly
- pregnancy and working with animals inc risk of meningitis with Listeria bacteria
21
Q
presentation of Neisseria Meningitidis
A
- Bacterial meningitis (15%)
- Meningococcal septicaemia (25%)
- Combination of both (60%)
22
Q
classic signs & Sx
A
- Fever
- Headache
- Photophobia
- Neck stiffness
- Petechial rash
23
Q
signs and Sx in young children
A
- fever
- N&V
- poor feeding
- irritability
- drowsiness
- confusion
- sudden fever & rigors
- muscle & joint aches
- cold extremeties
- Sx of raised ICP (bulging fontanelle, irregular breathing, abnormal tone)
- petechial rash (usually N meningitidis)
24
Q
Petechial rash
A
- usually in septicaemia but may be absent in meningitis
- blanching and macropapular in early disease, develops into petechial, non-blanching rash
- rapidly evolving rash = severe disease
- non-blanching = MED EMERGENCY
(glass test not in NICE guidance)
25
Kernig's and Brudzinski's sign in meningitis
* severe stiffness of the HAMSTRINGS causes an inability to straighten leg when hip is flexed to 90 degrees
* severe neck stiffness causes hips and knees to flex when the neck is flexed
26
diff between meningitis and sepsis
PRODROME SAME
- fever
- N&V
- malaise
- lethargy
MENINGITIS
- severe headache
- neck stiffness
- photophobia
- drowsiness/confusion
** death from inc ICP
SEPSIS
- limb/joint pain
- cold hands/feet
- pale/mottled skin
- oliguria/thirst
- rash
- tachycardia
- rigors
- abdo pain
** death from CV failure
27
diagnosis
* Hx and examination
* blood tests
* nasopharyngeal swab through mouth
28
blood tests for diagnosis
* FBC
* blood films
* CRP
* blood culture
* serology & PCR
* testing of CSF sample = GOLD STANDARD diagnostic test
29
When to start Tx?
empirical Tx initiated on strong clinical suspicion & should not be witheld until cultures taken
30
CSF sample
* Lumbar puncture drains CSF from back below end spinal cord
* NOT performed if pts:
– features of raised (ICP)
– haemodynamic instability
– clotting abnormalities or thrombocytopenia
* if meningitis, CSF sample appears turbid
* causative organism cultured from CSF sample
* bacteria may not be cultured if ABX have already been administered
31
general Tx for meningitis
* broad spec IV ABX
* ABX choice depends on most likely causative organism
* determined by age
* good CSF penetration essential
* ABX changes if necessary once causative organism ID
* guidelines reflect local patterns of resistance
32
empirical Tx - early Tx before hospital if practical
benzylpenicillin (NICE)
benzylpenicillin & cefotaxime
(parenteral)
33
When is benzylpenicillin witheld?
only in allergy only due to anaphylaxis
34
empirical Tx - hospital
ceftriaxone (3rd gen cephalosporin)
1st line over 3 months
35
Tx in under 3 months
* need ABX active against listeria
* cefotaxime + ampicillin/amoxicillin
* Listeria most likely in U3mths
36
supportive therapies
* Corticosteroids
* Intravenous fluids
* Enteral nutrition
* Anticonvulsant therapy if app (convulsions from inc ICP, pressure on brain)
* Management of complications of septicaemia and shock
– Respiratory support
– Correction of metabolic disturbances
– IV fluids
– Vasoactive therapies
– Renal replacement therapies if required
37
LT complications
* Hearing loss
* Orthopaedic complications
* Skin complications
* Psychosocial problems
* Neurological and developmental problems
* Renal failure
38
When is chemoprophylaxis indicated?
* prolonged close contacts - same household during the 7 days before presentation
* transient close contacts - directly exposed to large particle droplets/secretions from the RT of pt around time of admin to hospital
* patient - given as soon as able to take oral meds, unless treated with ceftriaxone
39
When is chemoprophylaxis NOT indicated?
– Staff and children attending same nursery/school
– Residents of nursing/residential homes
– Food/drink sharing or similar low level of salivary contact
– Travelling in next seat on same plane/train/bus
40
Chemoprophylaxis options
* given asap after diagnosis
* choice of ABX includes:
1. Ciprofloxacin
- rec for all age groups and pregnancy
- single dose admin
2. Rifampicin
- suitable for all pt groups (without c/i)
- BD for 2 days
- interactions
3. Ceftriaxone
- injection so only used when other Txs unsuitable
41
vaccination
Hib / Men C vaccine
* routine immunisation at 1 year
Quadrivalent Vaccines
* meningococcal polysaccharides A, C, W135 and Y vaccine (ACWY Vax®)
* quadrivalent meningococcal diphtheria-conjugate vaccine (MCV-4)
* suitable for individuals at risk & meningitis patients & close contacts
Men B vaccine
* NHS for babies born after Sept 2015
* Routine immunisation at 2, 4, 12mths
Other vaccines
* 5-in-1 vaccine
- DTaP/IPV/Hib vaccine
- routine imm at 8, 12, 16 weeks
* Pneumococcal vaccine
- routine imm at 8, 16 weeks, 1yr
42
reporting meningitis
if diagnosis of meningitis suspected, dr legally obliged to report to local health protection unit of the health porteciton agenct
