management of bacterial meningitis in children

8/7/2019 Management of bacterial meningitis in children

1/21

Meningitis Lumbar Puncture


2/21

Objectives

Signs of meningitis how good are they?

Who needs an LP considering the evidence Interpreting LP results

Absolute values

Before / After antibiotics


3/21

Causes of childhood acute bacterial

meningitis.

In children aged > 1 month two pathogenspredominate in unvaccinated populations usually

accounting for >80% of cases outside themeningitis belt:

Strep. Pneumoniae

H. influenzae

In children < 1month the range of pathogens iswider with common ones being:

Group B Streptococcus

E.coli

Klebsiella spp.


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Outcome of childhood acute bacterial

meningitis

Death

~30% fatality unless

meningococci are a

prevalent cause when

mortality is a little lower.


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Outcome of childhood acute bacterial

meningitis

Death ~ 30%

Severe Handicap ~ 25-30% Hemiplegia

Blindness

Deafness

Severe Learning Difficulty Severe behavioural disturbances

Severe Epilepsy.


6/21

Can we do better with hospital care?

Steroids?

The inflammation taking place around thebrain causes damage.

Fluid management?

Restrict fluids to reduce brain oedema

New antibiotics?

Ceftriaxone?


7/21

Can we do better with hospital care?

Steroids?

No good evidence that they reduce deaths. Fluid management?

Fluid restriction may do more harm than good

New antibiotics?Ceftriaxone there is NO good evidence that

such antibiotics reduce deaths (yet)


8/21

CNS - acute infectious disease

Cerebral

Malaria

Acute

Bacterial

Meningitis

Encephalitis

Abscess / TB

Any severe illness

causing respiratory or

circulatory failure


9/21

Who has bacterial meningitis and who needs

an LP? consider 100 cases of meningitis

Clinical signs in a febrile

child

Able to

detectMissed

Number

over-

diagnosed

1 Bulging fontanelle / Stiffneck

40 60 110

2 Signs in 1 or fits aged

6yrs60 40 215

3 Signs in 1 or 2 or partialor focal convulsions

70 30 495

4 Signs in 1 or 2 or 3 or

reduced consciousness80 20 915


10/21

So what is a sensible rule for LP?

At a minimum, if you want to avoid missing

meningitis (and deaths and handicap from

it), and avoid wasting antibiotics, at least LP

those with history of fever and one of:

Bulging fontanelle

Stiff neck

Fits if age 6 yrs Partial or focal fits

Reduced consciousness


11/21

Value of LP findings Acute

bacterial meningitis.

All the true acute bacterial

meningitis cases


12/21

Bedside assessment alone is very helpful.

75% of acute bacterial

meningitis cases can bedetected by examining

for CSF cloudiness or

turbidity at the bedside.


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CSF Cloudiness / Turbidity

A simple test of CSF

turbidity is to see if

normal print can be

read easily through

the sample CSF

should be crystal

clear.

Cloudiness usuallyappears at CSF

WBC counts >

200x106 Wbc per L


14/21

CSF culture is great but if it is not

available a microscope will provide

nearly all you need to know.

82% of acute bacterialmeningitis cases can be

detected by either turbidity

or a CSF white cell count

and using a cut-off of >50

Wbc per L. (>50 x 106 Wbcper L)


15/21

CSF microscopy, blood and CSF glucose

measures are highly sensitive.

96% of acute bacterial

meningitis cases can bedetected by turbidity, a CSF

white cell count of >50 Wbc

per L (>50 x 106 Wbc per L)

or a CSF glucose to Blood

glucose ratio


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17/21

But the lab needs. Specimens before treatment ideally

CSF must be processed within 1 hour of

collection

CSF cannot be put in a fridge

Only put CSF in an incubator if the temperature

is < 150C and it cannot be taken to the labquickly.


18/21

What do we use for treatment?

MoH recommends Penicillin +

Chloramphenicol

If you prove meningitis by LP then

Ceftriaxone is a very reasonable

alternative.but you should have an LP

result.


19/21

Summary Meningitis is suspected clinically but

confirmed by LP

Children will die and suffer disabilitybecause clinicians do not do an LP blaming the lab is no excuse.

If clinicians and lab staff work togetheracute bacterial meningitis can be accuratelydiagnosed.


20/21

The CSF sample is examined for presence and types of

white blood cells, red blood cells, protein content and

glucose level.Gram staining of the sample may

demonstrate bacteria in bacterial meningitis, but absence of

bacteria does not exclude bacterial meningitis as they are

only seen in 60% of cases and Gram staining is less

reliable in particular infections such as listeriosis.

Microbiological culture of the sample is more sensitive butresults can take up to 48 hours to become available.The

type of white blood cell predominantly present indicates

whether meningitis is bacterial (usually neutrophil-

predominant) or viral (usually lymphocyte-

predominant),although in the beginning of the disease this

is not always a reliable indicator. Less commonly,

eosinophils predominate, suggesting parasitic or fungal

etiology.


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The concentration of glucose in CSF is

normally above 40% that in blood. In

bacterial meningitis it is typically lower; the

CSF glucose level is therefore divided by

the blood glucose (CSF glucose to serumglucose ratio). A ratio less than 0.4 is

indicative of bacterial meningitis;in the

newborn, glucose levels in CSF are

normally higher, and a ratio below 0.6

(60%) is therefore considered abnormal.

management of bacterial meningitis in children

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