Collapse and sudden illness, including seizures Flashcards
what must we suspect in pyrexial pt with reduced consciousness?
intracranial infection-most commonly meningitis
how does the treatment of a pt with bacterial meningitis who has a known penicillin allergy differ from that of a pt without?
10% of pen sensitive pts will also be allergic to cephalosporins, but depending on hx, this risk may be worth taking in some pts
if definite hx of anaphylactic reaction than can give chloramphenicol IV. (or a carbapenem e.g. meropenem).
what important complication of meningitis may help to be prevented through use of dexamethasone tment for 4 days in adults with pneumococcal meningitis?
deafness
but be sure to discontinue dexamethasone if TB or a non-bacterial cause is identified
dexamethasone can be used as adjunctive therapy in all causes of bacterial meningitis, and should be started before or at same time as Abx and continued for 4 days, as has been shown to improve outcomes. 8.3mg QDS.
been shown to reduce mortality in pneumococcal meningitis.
contraindications to lumbar puncture?
coagulopathy shock severe hypotension raised ICP, papilloedema GCS less than 13 slow pulse, raised BP and irregular breathing (Cushing's triad) abnormal posturing dilated pupils prolonged or focal seizure focal neurological signs widespread purpuric rash
how can meningitis result from otitis media?**
middle ear infection can spread to involve the mastoid air cells-acute mastoiditis, and then spreads from here to involve the meninges.
RFs for meningitis?
CSF shunts or dural defects spinal procedures e.g. SA, may be more susceptible to pseudomonas bacterial endocarditis cirrhosis malignancy-more susceptible to listeria DM alcoholism IV drug abuse renal insufficiency CF splenectomy and sickle cell disease-increased suscpetibility to encapsulated organism infection-N.menigitidis, S.pneumoniae crowding e.g. college students-meningococcal disease susceptibility *note now 17-18 yr olds offered the A,C,W,Y vaccine (quadrivalent).
what problem may develop from menignitis if disease causes obstruction between the brain ventricles?
non-communicating hydrocephalus*
what is aseptic meningitis? what can cause this?
meningeal inflammation with cells in CSF, but gram stain -ve with no cultured bacteria on standard media
partly treated bacterial meningitis
viral infection-HSV, VZV, mumps, measles, coxsackie, HIV
fungal infection-cryptococcus, histoplasma
parasitic infection-angostrongyliasis
other organisms unable to be cultured
kawasaki disease-idiopathic systemic vasculitis, cause of persistent pyrexia in children
mollaret’s meningitis-benign recurrent aseptic meningitis, ?role of HSV-2
clinical px of meningitis?
pyrexia headache neck stiffness photophobia back rigidity bulging fontanelle note the relatively nonspecific symptoms and signs that might be seen in young children-fever, poor feeding, distress, N+V, diarrhoea, drowsiness, apnoic or cyanotic attacks seizures shock altered conscious state kernig's sign-pain and resistance on passive knee extension with hips fully flexed brudzinski's sign-hips flex on bending the head forwards
investigation of choice for meningitis diagnosis?
lumbar puncture:
CSF sent for gram staining, ziehl-neelsen staining (TB),culture, virology, cytology, biochemistry-glucose, protein, rapid antigen screen, PCR, India ink-for cryptococci
rpt LP if symptoms and signs persist, may be -ve initially
indication for IV aciclovir in meningitis tment?
herpetic meningitis
should be started immediately if any suspicion of HSV encephalitis
additional antimicrobial therapy given if listeria (gram +ve bacillus) suspected cause of bacterial meningitis e.g. older people, immunocompromised and newborns?
ampicillin
*or IV amoxicillin if pt over 55yrs
role of maintenance IV fluids in patients with bacterial meningitis?
associated with better neurological outcomes, but must be used cautiously in patients with raised ICP, myocardial dysfunction or ARDS-lung damage and release of inflammatory mediators cause increased capillary permeability and non-cardiogenic pulmonary oedema, often accompanied by multiorgan failure.
indications for IM/IV benzylopenicllin tment in the community in prehosp tment of meningitis?
only if pt has non-blanching rash or if may be significant delays in getting the pt to hospital.
complications of meningitis?
immediate: septic shock, DIC, coma, cerebral oedema and raised ICP, septic arthritis, pericardial effusion, haemolytic anaemia (H.influenzae)
subdural effusions
SIADH
seizures
delayed: decreased hearing or deafness, other CN dysfunction, multiple seizures, focal paralysis, hydrocephalus, subdural effusions, ataxia, blindness, intellectual defecits, Waterhouse-Friderichsen syndrome-adrenal failure due to bleeding into the glands as result of severe bacterial infection with N.meningitidis, and peripheral gangrene.
