Meningitis Flashcards
What is meningitis
Infection and inflammation of the meninges
What is meningism
Thunderclap headache
Photophobia
Vomiting
Neck stiffness due to spasm on flexion
What can cause meningism
Meningitis
SAH
Migraine
Sinusitis
What should you beware of
Fever Vomiting Lethargy Confusion Even in absence of headache / photophobia
What are bacteria causes
Neisseria meningitides
S.pneumonia
H.influenza - more in young-18
Neonate
E.coli
GBS
Listeria monocytogene - also in >50
What are viral causes
HSV and VZV = most common Enterovirus Mumps EBV HIV CMV - immunocompromised
What causes shunt associated meningitis (VA / VP)
Coag -ve staph - S.epiderdimis
S.aureus
Coliforms
What do you do for shunt associated
Refer to neurosurgeon
What are non-infective causes
Drugs SLE Sarcoid Malignancy Treat as infective 1st then look for these if no infection
What does CSF show in non-infective
No organism
Excessive WCC / protein
What are RF for meningitis
Alcohol Immunocompromised - HIV / DM / congenital ENT condition Surgery Splenectomy Skull trauma FH / contact
How is meningitis transmitted
Close contact Vertical from mother to baby - group B strep Adjacent infection - sinusitis Neurosurgery Head injury / trauma
How do you Dx meningitis
Blood culture before Ax if possible
Blood PCR
LP = definite if no CI
Always do CT prior to LP to ensure no mass
What do you send CSF for
Gram stain and culture - bacteria PCR - viral AAFB on ZN for TB Cell count Antigen detection Glucose Protein WCC
What other tests do you do
Bedside obs NPA and throat swab to isolate Bloods- FBC, U+E, LFT, clotting, CRP Blood glucose ABG or VBG CXR as part of sepsis screen
What are CI to LP
Focal neuro suggesting mass - Papilloedema - Seizure Chairi malformation Raised ICP Unstable patient Bleeding disorder / DIC Immunocompromised Infection over LP site Meningococcal septicaemia as thrombocytopenia
What are complications of LP
Spinal headache Nerve root trauma Cyst Infection Brain herniation if raised ICP
How does spinal headache present
Bilateral
Improves when supine
How do you Rx
Fluid
Caffeine
Epidural blood patch
What are symptoms of nerve root trauma
Electric shock
Back pain
Altered mental
CN abnormalities
How do you Rx and Dx if nerve been injured
Raise head
Mannitol
Steroid
Intubate
Nerve conduction studies
What empirical therapy do you give for meningitis
BenPen in community Amox +cefaxime if <3 months or >60 Cefotaxime if >3 months Chloroamphenicol if allergic Aciclovir if any signs of encephalitis Steroid if >3 months and not meningococcus
What does CSF show in bacterial meningitis
Turbid colour Increased opening pressure Elevated WCC Neutrophils predominate >50% Reduce glucose Increased protein Increased lactate
What does CSF show in viral meningitis
Clear colour Increased opening pressure can be normal Elevated WCC (lymphocytes) Neutrophils <10% Normal glucose Normal or raised protein
What does CSF show in TB
Cloudy Increased pressure Increased WCC Reduced glucose Increased protein Mixed cell / lymphocytes
When may opening pressure be normal
Viral
TB
FUngal
What do you do if organism killed by Ax before LP
Look at protein / glucose
What should you never do
Delay Rx if life-threatening
What causes meningococcal
Neisseria meningitdes
Gram -ve
How does meningococcal present
Meningism Rapid deterioration in mental Systemic upset - flu / fever Seizures Irritable Skin rash - petechial / maculopapular (20%) Petechiae conjunctiva SEPTIC SIGNS
What should you never wait for
Skin rash to appear
How do you assess
A - can't maintain if unconscious B - increased RR / O2 C - shock D - AVPU / pupils / GCS / papilloedema / focal neuro E - rash / temp /
What is Kernig sign
Can’t extend knee joint when hip joint flexed
Signs of meningeal irritation
What is Bruzinski sign
Hip and knees flex when neck flexed
When do you do a CT
Most people get a CT just to make sure
Rule out abscess
Make sure safe to do LP
Indication Immunocompromised Hx CNS - stroke Seizure within one week of feeling unwell Swollen optic disc Low GCS Focal
When may you not need LP
Confident Dx with typical rash
Do you still do LP if Ax given
Yes as changes in CSF can stay for 48 hours
How do you treat meningococcal
Early Ax - cefotaxime
Fluid resus
ICU
Support shock and raised ICP due to cerebral oedema
What do you give pre-hospital
Benpen IM
Always give if suspect
What do you give on discharge
Rifampicin or ciprofloxacin
What do you do for raised ICP
Low threshold for intubation and ventilation
Mannitol
What do you give prophylaxis
Public health must be notified of all bacteria meningitis All close contacts Ciprofloxacin preferred to Rifampicin Target immunisation Eliminate carriage
What vaccine are available
Meningococcal A and C
Pneumococcus
H. influenza
What suggests bad prognosis
Delay in therapy Age extreme Purpura Shock + no meningism DIC Metabolic acidosis Neuro deficit Absence of raised WCC
DDX
Encephalitis - headache / reduced GCS
SAH - fever unlikely
Migraine
What is DIC
Abnormal clotting in small blood vessels
Low platelet
Increased fibrin
What suggests chronic meningococcaemia
Meningococcal sepsis in absence of meningitis Fever >1 week Rash Joint pain Malaise
What is meningococcal septicaemia
CSF sterile
Septicaemia from meningococcal source (bug) - not infection in the menigniges
Wha is mortality
50% die in 24 hours
How does meningococcal septicaemia present
Rapid decreased GCS/ change in mental Fever Headache Purpuric rash = common feature - Not always present in meningitis Septic shock Low urine / tachy / hypotension DIC Acidosis Adrenal insufficiency
How do you Dx
Blood culture / PCR
LP sterile so if suspect septicaemia don’t bother
How do you Rx
Treat sepsis Supportive Inotropes Vasodilators Steroids Senior
What causes WCC to decrease
Seizure infection with septicaemia and DIC
What are complications of septicaemia
Seizures
Organ failure
Permanent neuro
Limb gangrene
What is Waterhouse Fredrickson Syndrome
Haemorrhage into adrenal gland causes insuffieincy
Hypotensive
Low Na and high K
What causes Pneumococcal meningitis
Strep pneumonia
What else can s.pneumonia cause
Otitis media
Sinusitis
Pneumonia
What is most common in adults
Pneumococcal
How does it present
Acute
Meningism
More likely altered consciousness/ focal neuro / seizures
GCS <15
What is uncommon in pneumococcal
Petechiae
What are RF
Age URTI Pneumonia Sinusitis Endocarditis Head trauma Alcohol Splenectomy
What should you also do
CXR as 50% will have pneumonia
How do you treat
Benzypen
Ceftriaxone if resistant
What else do you give and why
Dexamethasone
Reduce likelihood of neuropathy / hearing loss
Same time as 1st dose of Iv Ax
How do you prevent
Once off Pneumococcal vaccine if >65 Children DM Immunocomprmoised Chronic disease inc chronic liver Asplenia + CKD = 5 year booster HIV Cochlear implant / skull trauma Cerebral spinal fluid leaks
What are complications
Increased ICP and brain herniation Brain damage Sensorineural hearing loss Visual loss CN palsies Ataxia Hemiparesis Obstructive hydrocephalus Seizure Epilpesy
When do you give dex
All meningitis except meningococcus
What does H.influenza B cause
Mild URTI
Rapid deterioration
Fever
Lethargy
What is rare
Meningism
Petechiae
Nuchal rigidity
Who is at risk
Young children
Rare as vaccine
How do you treat
Cefotaxime as B-lactamase resistance
Dexamethasone
Vaccine
What do you give prophylaxis
Rifampicin
What is Listeria monocytogenes
Gram +ve rod
Important cause of neonatal meningitis
Brain abscess
Wha does it cause in pregnancy
Febrile flu
When is it important to think of
Immunocompromised
Newborn
How do you Dx
Blood culture
How do you Rx
Iv amoxicillin + Gent
Ceftriaxone
What are complications of Listeria
Long term neuro
Brain abscess
Abortion
Neonatal sepsis
How does TB meningitis occur
Rupture of subependymal tubercle into SAH
Post primary event
Extrameningeal TB
What are symptoms of TB meningitis
Meningism Low grade fever Extra-meningeal TB Lethargy Chronic headache Change in mentation Weight loss Night sweats Malaise
How do you Dx TB meningitis
AAFB ZN CSF Only 30% +Ve Repeat LP PCR sputum / urine Mantoux
When should you always consider TB
Reduced glucose and gram stain -ve
How do you treat
Speicalist
What can Leptospirosis and Lyme cause
Septicaemia Meningism Fever Rigors Myalgia Vomiting Conjunctival effusio Rash Hepato-renal damage
How do you Dx
Serology
Only small % develop
What are viral causes
HSV and VZV = most common Enterovirus - Echo / Coxsackie EBV HIV CMV
When is CMV common
Immunocompromised
How does viral present
Non specific prodromal Rapid headache Low grade fever Phosphobia Stiff neck Usually lucid and alert
What virus presents with rash
Enterovirus
What is viral meningitis often associated with
Encephalitis Lethargy Confusion Seizures Focal neuro
When is viral common
Young adults and children
Immunocompromised
Travel
How do you Dx
PCR CSF
Throat swab PCR
HIV test
How do you treat
IV acyclovir
Most make full recovery
Supportive
IV Ig if chronic
How do you prevent
MMR and Hib vaccine
What causes fungal meningitis
Cryptococcus neoformans
How does it present
Subacute Low grade fever Headache Nausea Lethargy Confusion
Who is at risk
HIV
DM
Lymphoma
Immunocompromised
How do you Dx
India ink CSF
Gram stain candida
Term cryptococcal antigen in CSF
How do you treat
Specialist
IV amphotericin B
How you prevent
Long term chemoprophylaxis with fluconazole if HIV
