Quick question about viral vs bacterial meningitis treatment protocol?

[nope80]

On a clinical/practical level, when someone presents to the emergency room suspected case of meningitis, they do an LP. Between the time of doing an LP and getting the results back, do they immediately start antibiotics? Even if it is a suspected viral? If so, when do they decide to discontinue the antibiotic use, after the CSF culture results? I know that when you look up viral meningitis treatments they say its pretty much all supportive care and that it resolves within 2 weeks on its own...Also, what is the consensus on steroid use? I know that it is beneficial in S.pneuom and H.flu but when a person walks in the ED, you don't know what they have yet...anyone, any more indepth insight about this would be appreciated! Thanks.

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[njac]

I'm in pharmacy school but we were taught start with Ceftriaxone, Acyclovir, and some dexamethasone. If listeria is a possibility throw in some Ampicillin for fun.

Especially in the ED when you don't know what they have.

 

[nope80]

See I thought dexamethasone was only for bacterial (specifically pneumococcal) but are you saying that when they first present, you don't know if it is bacterial or viral so its standard to just treat?

Also I thought acyclovir was specifically for infants with HSV or other immunocomp patients...

 

[werd]

you usually give them empiric treatment for bacterial meningitis before even getting the LP (vanc, ceftriaxone +/-ampicillin). if someone's really sick or there's a high suspicion for viral you'd start acyclovir as well. as for how to scale back after the LP it varies by situation. a clean tap and you can d/c antibiotics; tap suggesting viral and you'd begin acyclovir (treats HSV and VZV). if the tap appears to be viral and they're really sick, you may continue bacterial coverage anyway until the bacterial culture's negative or a viral PCR is positive. viruses except for herpes family are usually treated supportively.
my understanding of the dexamethasone thing is there's varied evidence. i think it helps in kids and i think it helps with strep pneumo, but if you give it to all meningitis comers there's no benefit. at my hospital we don't usually give dex to adults. hope this helps.

 

[lazycat]

firstly, to indicate antibiotic for a meningitis patient, we ought to diagnose that is a viral or bacterial meningitis. and we can do it without labs results in some cases.
when observation the CSF , i think we could give a first diagnosis , if the fluid is clear and opening pressure is low, we can guess that a viral meningitis! if the color is not clear or yellow, with high opening pressure, usually > 180 mmH20, we doubt it from bacterial meningitis, and intravenous ceftriaxone 4g is needful.
if we could not diagnose after lumbar puncture, uhm, we have to indicate high dose antibiotic until we have results from lab. we also indicate dexamethasone before or at the same time with initial dose of antibiotic . i think dexamethasone reduce the inflammatory meningeal vessels hence prevent the increasing intracranial pressure.

 

[lazycat]

for reference : Corticosteroids for Bacterial Meningitis
http://content.nejm.org/cgi/content/full/358/13/1399

 

[BigRedBeta]

Standard thought says that if you're suspicious enough to do an LP, you start antibiotics and steroids. A single, correctly sized dose of steroids never hurt anyone, but the benefits can be huge.

Empiric antibiotics vary with patient age though, and you also need to assess risk factors for other types of infections. This is why you need to carry a Sanford guide or the Nelson's Pediatric Antibiotic guide around with you.

As a future peds intern, I'm going to have the antibiotics ready or on their way while starting the LP. There is rapid sterilization of the CSF after first antibiotic dose (within hours), so it's not going to be one of those things where I give the antibiotics and then wait 6 hours to do the tap. If the tap is difficult and there is prolonged time between first dose and getting CSF, that will likely mean that you've bought the patient 2 weeks of empiric antibiotics...which may include drugs that are only IV - so they're going to be in the hospital a long time or get a PICC.

You can stop antibiotics/antivirals after negative culture results (since that's the gold standard) from an appropriately timed CSF sample...so usually that's on Day 3 or 4 depending on your institution and their reporting of culture results.

Cochrane Review on giving of steroids:

http://www.cochrane.org/reviews/en/ab004405.html

 

[njac]

4 gm of IV Ceftriaxone? I've seen 2 gm IV Q12H but not a 4gm load.

Literature?

 

[werd]

here's some usual meningitis abx in a nutshell...

adults: ceftriaxone (covers meningococcus, h.flu, and most strep pneumo) and vanc (covers the 5 or so % of strep pneumo resistant to ceftriaxone)

immunosupressed or over 55: also give ampicillin (covers listeria)

infants: ampicillin and gent (covers listeria, e.coli, and group b strep)

i think the literature says culture results aren't affected if the tap is within 4 hours of giving antibiotics, but don't have time to find the paper. werd.

 

[sprinkibrio]

We were taught that:
1st: if you suspect *bacterial* meningitis but they have focal signs and papilledema do a CT first to rule out a mass. LP can cause herniation with a mass.
2nd: empiric treatment with dexamethasone always, before the antimicrobial
3rd: empiric antimicrobial treatment is dependent on age and immune status:
<2 mo. ampicillin, broad spectrum cephalosporin, 2 mo-50 yrs vancomycin, broad spectrum cephalosporin, >50 yrs vancomycin, broad spectrum cephalosporin, ampicillin, immunocompromised ampicillin, ceftazidime, history of neurosurgery, head trauma, CSF shunt ceftazidime, vancomycin

I think you distinguish bacterial vs. aseptic based on history... aseptic meningitis with no other findings would be herpes or enterovirus (which is more common in children in the summer).

BTW, this helped me study, thanks guys!

 

[TMP-SMX]

Yeah you definitely want to rule out mass effect by CT as herniation is pretty much death.

 

[lazycat]

4 gm of IV Ceftriaxone? I've seen 2 gm IV Q12H but not a 4gm load.

Literature?

i mean 4g/day.