Meningitis Flashcards
Name some bacterial causes of meningitis and list them by which age group they infect
Neonate - E. coli, group B strep, listeria
Children - H. influenzae B, N. meningitidis
Elderly - S. pneumoniae, L. monocytogenes
Name some risk factors for meningitis
CSF defects
Spinal procedures
Endocarditis
Diabetes
Alcoholism
Splenectomy
Crowded populations
Name some signs and symptoms of meningitis
Fever and flu-like symptoms
Headache
Nuchal rigidity
Photophobia
Seizures
Meningococcal rash
Altered mental state
Shock
How does the CSF appear in bacterial and viral causes of meningitis
Bacterial CSF - cloudy, high protein, high polymorphic WCC, low glucose, minimal RBCs
Viral CSF - clear/cloudy, norma/raised protein, high lymphocytes, normal glucose, minimal RBCs
Describe the pathophysiology behind meningitis
Local invasion of bacteria through nasopharyngeal mucosa into blood where they cause endothelial injury and increase BBB permeability
Bacteria invade the meninges and cause subarachnoid space inflammation which increases BBB permeability and increases cerebral outflow resistance
Subarachnoid space inflammation causes headache and nuchal rigidity
Have RICP because of increased BBB permeability (vasogenci oedema), increase CSF outflow resistance (intersitial oedema) and subarachnoid inflammation (cytotoxic oedema)
All results in decreased cerebral blood flow and meningitis
Why does a maculopapular rash develop in meningitis
Release of cytotoxins by bacteria into bloodstream results in microvascular thrombosis as the cytotoxins cause sluggish circulation, increased PA-1 to impair fibrosis and low levels of protein C, S and antithrombin
What is the treatment for meningitis
Give IV ceftriaxone
Give paraenteral benzylpenicillin if in GP -> admit to hospital
Give pain relief, anti-pyretics and IV fluids
Give dexamethasone to prevent hearing loss
Give antivirals if virus cause - acyclovir if herpes, ganciclovir if CMV
Name some complications of meningitis
Septic shock
DIC
Coma
Cerebral oedema
RICP
Death
SIADH
Hearing loss
Intellecutal deficits
Hydrocephalus
Focal paralysis
