5. Incidence and
etiology
pyogenic
meningitis
•Bacterial meningitis is commonest in infancy
•May result in death within hours of onset if not
treated
•Responsible for 3% hospital admissions
•More frequent in infant males
•Any organism can cause meningitis
•Great risk during 6-12 months and 95% cases
occur between 1month and 5years
6. Causative agents for different
ages
pyogenic
meningitis
Age Causative agents
0 – 2 months •Escherichia coli
•Group B streptococci
•Staphylococcus aureus
•Listeria monocytogenes
2months – 2
years
•Haemophilus influenzae type b
•Streptococcus pneumoniae
•Neisseria meningitides
2 years – 21
years
•Neisseria meningitides
(serotypes A, B, C, Y and W 135)
•Streptococcus pneumoniae
(serotype 1, 3, 6, 7, 14, 19, 21,
23)
•Haemophilus influenzae
8. Pathogenes
is
•Causative agent enter CNS via blood or
direct invasion
•Anatomic or congenital defect can also
cause invasion
•Inflammation of meninges initiated when
cell elements of organism disrupt blood
brain barrier
•Followed by outpouring of polymorphs and
fibrin
pyogenic
meningitis
9. •Release of cytokines and chemokines in
CNS stimulated by bacteria
•Meninges become swollen, inflamed and
covered in exudates
•Early in illness cerebral edema present
and ventricles reduced in size
•Pressure on peripheral nerves may lead to
motor or sensory deficit
•Communicating hydrocephalus due to
adhesive thickening of arachnoid in basal
cisterns pyogenic meningitis
pathogenesis
10. •Obstructive hydrocephalus due to
fibrosis blocking aqueduct of sylvius or
foraminas
•Affected cranial nerves cause deafness
and vestibular problem
•Cerebral vessels and cranial nerves can be
involved and may lead to permanent
neurologic damage
•Cerebral atrophy by thrombosis of small
cortical veins pyogenic meningitis
pathogenesis
11. •Inflammation involving veins crossing
subdural space lead to increase in
vascular permeability and loss of albumin
into subdural space
•Hypoglycorhacia by decreased transport
of glucose across the inflamed choroid
plexus and increased use by host
•Seizures by electrolyte imbalance
ultimately depolarization of neuronal
membranes pyogenic meningitis
pathogenesis
12. Clinical
features
Meningitis always must be considered in
any young infant whose temperature is
greater than 100.7°F (38.2°C) and who
has no obvious site of infection
pyogenic
meningitis
13.
14. Neonates and
infants
•Gram negative organisms are
commonly responsible
•Infective illness in mother, prolonged rupture of
membranes or difficult delivery put the
newborn at risk
•Premature infants have low level of antibodies
•Predisposing factor is spina bifida or dermal
sinus
15. •Initial signs are subtle
•Fever occurs in 50% of cases
•Infant is ill looking and feeds poorly
•May develop vomiting, hypothermia,
lethargy, convulsions
•Has bulging anterior fontanelle, head
retraction and high pitch cry
pyogenic meningitis neonates and
infants
16.
17. Older
children
•Classic signs preceded by upper respiratory
or GIT symptoms
•High grade fever, head ache and projectile
vomiting
•Seizures are common
•Increased CSF pressure leads to bulging
fontanelle and diastasis of sutures
pyogenic
meningitis
18. •Neck stiffness, positive kerning's
sign and brudzinski’s sign
•Cranial nerve palsies and papilledema
•Hemiplegia in cases late reported, ataxia may
also be present
•Patient may be semi comatose or comatose
•Meningococcal meningitis is characterized by
the presence features of Waterhouse
Friderichsen syndrome
pyogenic meningitis older
children
19. •Otitis media and mastoiditis is likely to
lead streptococcal or pneumococcal
meningitis
•Staphylococcal infection is likely following
surgical procedures, skull fractures or skin
infections
•If there is no specific sign between 6months –
2years then H. influenzae is the cause
•Onset of clinical signs is sudden in
meningococcal and S. pneumoniae infection
pyogenic meningitis in older
children
20.
21. Investigation
s
Lumbar puncture
•CSF pressure should be noted, fundi
checked for papilledema
•Xanthochromia due to jaundice, bilirubin
from hemorrhage or increased protein
•If lumbar puncture is traumatic; one
leukocyte per 700 RBC in CSF is subtracted
and 1 additional mg protein is added in CSF
protein for 800 RBC
pyogenic
meningitis
22. •CSF glucose should be compared to
blood glucose, CSF glucose is 2/3 of
blood glucose
•In CSF of neonates normally there are up
to 30 lymphocytes and 150mg/dl protein
•Gram stain is important to recognize
the causative agent
pyogenic meningitis investigations
LP
23.
24. CSF findings in various CNS disorders
Conditon Color Leucocytes Protein mg/dl Glucose mg/dl
Normal Clear 0 – 5 20 – 45 >50 or 75% of
60 – 70% blood glucose
lymphocytes
Acute bacterial Opalescent 100 –20000 100 –500 <40
meningitis to purulent PMN predominate May be none
Tuberculous Opalescent 10 – 2000 >50 <40
meningitis PMN early but May be none
lymphocyte later
Viral Clear 5 – 500 30 – 150 30 – 70
encephalitis Mostly
lymphocytes
PMN early
pyogenic meningitis investigations
LP
26. Contraindications for immediate
LP
pyogenic meningitis investigations
LP
•Increased ICP especially with focal
neurologic deficits
•Severe cardio pulmonary compromises
•Infection of skin overlying the site of LP
•Bleeding or clotting disorder
27. Recommendation for repeat
LP at 24 – 36 hours
pyogenic meningitis investigations
LP
•All neonates
•Meningitis caused by S. pneumoniae and
gram negative enteric bacilli
•Lack of cranial improvement in 24 –
36hours after therapy
•Prolonged or second fever
•Recurrent meningitis
•Immunocompromised patients
28. CSF culture
The yield of CSF culture decreases soon
after antibiotic therapy has been started.
More sensitive technique, polymerase
chain reaction may help to diagnose cases
of bacterial meningitis in patients treated
by antibiotics
Blood culture
90% H. influenzae and 80% S.
pneumoniae
pyogenic meningitis
investigations
29. Blood counts
Total and differential leukocyte count;
generally there is leucocytosis with
predominant polymorphs
X – ray chest
To rule out TB and pneumonia
CT scan
pyogenic meningitis
investigations
30. Indications for CT
scan
pyogenic meningitis
investigations
•Newborn except for disease caused by
listeria
•Prolonged comatose condition
•Seizures 72 hours after start of treatment
•Continued excessive irritability
•Focal neurologic findings
•Persistently abnormal CSF findings
•Relapse or recurrence
31. Rapid diagnostic tests
•Concurrent immuno electro phoresis
•Latex particle agglutination
•ELISA to detect bacteria antigen in CSF
•CSF lactate level
•Enzyme radioisotope to detect activity
of ß lactamase in CSF
Gram staining
Smears of petechial or purpuric lesions on
skin pyogenic meningitis
investigations
34. •Body weight, serum electrolytes monitored
12 hourly
•For fever sponge and give antipyretics
•Feeding continued and give tube feeding if
necessary
•Fluid restricted to 60%, not indicated in
hypotension
•Care of comatose patient
•IV diazepam for seizures,
35. Specific
measures
Antibiotics
•Appropriate antibiotic given by culture report
•Term infants in 1st month given combo
of ampicillin with gentamicin or
cefotaxime
•Low birth weight preterm infants presenting
late should be given vancomycin and an
aminoglycoside
pyogenic meningitis
management
36. •1 – 2 month infants given ampicillin ad
ceftriaxone
•Resistant strains treated with
vancomycin alternatively meropenem
•Duration of therapy is 7 – 10 days
Steroids
•Dexamethasone for 2 – 4 days
•Given before antibiotic is started for good
result
pyogenic meningitis management
specific
37. Treatment of
complications
Cerebral edema and raised ICP
•Head elevated about 30°
•Steroids for reducing inflammation and brain
water content
•Mannitol
Subdural effusion
•Symptomatic effusion should be aspirated
pyogenic meningitis
management
39. Inappropriate ADH
secretion
•Hyponatremia, coma, seizures, weight
gain, puffiness of face, decreased urine
output
•Treated with fluid restriction and diuretics
Waterhouse Friderichsen syndrome
•Patient in shock with hypotension petechial
rash
•Give normal saline/plasma, steroids
and dopamine infusion
pyogenic meningitis management treatment of
complications
42. Prognosi
s
pyogenic
meningitis
•Worse prognosis in young children with higher
bacterial colony counts, intractable seizures,
subdural effusion, bacteremia and prolonged
fever, thrombocytopenia, low ESR, absence of
leukocytosis, DIC, rapidly progressive purpura
in 12hours, hypotension or coma
•Mortality rate is 8 – 25%
•35% have permanent deficit