BAC MENINGITIS Flashcards
- Is an acute purulent infection w/in the subarachnoid space
- associated w/ a CNS inflammatory reaction that may result in decrease consciousness, seizures, raised intracranial pressure and stroke
Meningitis
Involved in the inflammatory reaction of Meningoencephalitis
- Meninges
- SAS
- brain parenchyma
Organisms most often responsible for community-acquired bacterial meningitis
- S. pneumoniae
- Neisseria meningitidis
- GBS
- L. monocytogenes
- H. influenzae
- N. meningitidis - causative agent of recurring epidemics of meningitits every 8-12 yrs.
Bacterial organism Most common in adults >20 years of age
Streptococcus pneumoniae
Bacterial organism Incidence has decreased with routine immunization of 11-18-years-old with quadrivalent meningococcal glycoconjugate vaccine.
Neisseria meningitidis
Bacterial organism Can cause meningitis in individuals with
chronic and debilitating diseases (diabetes, cirrhosis, chronic UTI) and can complicate neurosurgical procedures.
Gram (-) Bacilli
Bacterial organism Otitis, mastoiditis, and sinusitis are predisposing and associated conditions for meningitis
- Haemophilus sp.
- Enterobactereciae
- Staphylococcus aureus
Bacterial organism Meningitis complicating endocarditis
- Staphylococcus aureus
- Streptococcus viridans, Strep. bovis
- HACEK Group
Bacterial organism
- Previously responsible for meningitis HACEK or. predominantly in neonates
- Reported with increasing frequency in individuals aged >5O years
Group B Streptococcus
Bacterial organism
- important cause of meningitis in neonates (<1 month of age), pregnant women, individuals >60 years, and immunocompromised individuals of all ages.
- acquired by ingesting foods contaminated by Listeria.
Listeria monocytogenes
Bacterial organism causes meningitis in unvaccinated children and older adults
H Influenza
Classic clinical triad of BACTERIAL MENINGITIS
- Fever
- Headache
- Nuchal rigidity
Clinical Manifestation of Bacterial Meningitis
- Decrease level of consciousness (>75% of patients)
- Fever, Headche
- Nausea , Vomiting and Photophobia
- Seizures (20-40%)
- Raised ICP
- Kernig’s sign
- Brudzinski’s sign
- Rash of meningococcemia
- Major cause of obtundation and coma
- > 90% CSF opening pressure >180 mmH20, 20%: >400 mmH20
Signs: Deteriorating level of consciousness, papilledema, dilated poorly reactive pupils, sixth nerve palsies, decerebrate posturing and Cushing reflex (bradycardia, hypertensions and irregular respirations) - Cerebral herniation - most disastrous complication
Raised ICP
DIAGNOSIS of Bacterial Meningitis
- Blood Culture
- Lumbar puncture for CSF evaluation
- CT scan or MRI
- Biopsy of petechial skin lesions
CSF PATHOGEN PANELS OF BACTERIAL MENINGITIS
- Latex Agglutination (LA) Test
- CSF bacterial PCR assay
- Limulus amebocyte lysate assay
Cerebrospinal Fluid (CSF) Abnormalities in Bacterial
- Opening pressure:
- White blood cells:
- Red blood cells:
- Glucose:
- CSF/serum glucose:
- Protein:
- Gram’s stain:
- Culture:
- PCR:
- Latex agglutination:
- Limulus lysate:
- Opening pressure: >180 mmH,0
- White blood cells: 10/tL to 10,000/L; neutrophils predominate
- Red blood cells: Absent in nontraumatic tap
- Glucose: <2.2 mmol/L (<40 mg/dL)
- CSF/serum glucose: <0.4
- Protein: > 0.45 g/L
- Gram’s stain: Positive in >60%
- Culture: Positive in >80%
- PCR Detects bacterial DNA
- Latex agglutination: May be positive in patients with meningitis due to Streptococcus pneumoniae, Neisseria meningitis, Haemophilus influenzae type b, Escherichia coli, GBS
- Limulus lysate Positive in cases of gram-negative meningitis
TREATMENT : Empirical Antibiotic Therapy
- begin antibiotic therapy within 60 min of a patient’s arrival in the emergency room
- initiated in patients with suspected bacterial meningitis before the results of CSF Gram’s stain and culture are known
Empirical therapy of community acquired suspected meningitis in children & adults
- Combination of Dexamethasone, 34 or
- 4” gen cephalosporins, vancomycin plus acyclovir
good coverage for susceptible S. pneumoniae, group B streptococci, and H. influenzae and adequate coverage for N. meningitidis
Ceftriaxone or Cefotaxime
in vitro activity similar to that of cefotaxime or ceftriaxone against Sneumoniae and N. meningitidis andgreater activity against Enterobacter species and Pseudomonas aeruginosa
Cefepime
added to the empirical regimen for coverage of L. monocytogenesin individuals <3 months of age, those >55, or those with suspected impaired cell-mediated immunity
Ampicillin
added to cover gram-negative anaerobes in patients with otitis, sinusitis, or mastoiditis.
Metronidazole
hospital acquired meningitis (following neurosurgical procedures) tx
Combination of Vancomycin and Ceftazidime or Meropenem
- Highly active in vitro against L. monocytogenes
- effective in cases of meningitis caused by P. aeruginosa
- Shows good activity against penicillin-resistant pneumococci
Meropenem
Antibiotics Used in Emperical Therapy of Bacterial Meningtis and Focal CNS Infections
INDICATION:
Preterm infants to infants <1month
Ampicillin + cefotaxime
Antibiotics Used in Emperical Therapy of Bacterial Meningtis and Focal CNS Infections
INDICATION:
Infants 1-3 months
Ampicillin + cefotaxime or ceftriaxone
Antibiotics Used in Emperical Therapy of Bacterial Meningtis and Focal CNS Infections
INDICATION:
Immunocompetent children >3 months and adults <55
Cefotaxime, ceftriaxone, or cefepime + vancomycin
Antibiotics Used in Emperical Therapy of Bacterial Meningtis and Focal CNS Infections
INDICATION:
Adults >55 and adults of any age with alcoholism or other debilitating illnesses
Ampicillin + cefotaxime, ceftriaxone
or
cefepime + vancomycin
Antibiotics Used in Emperical Therapy of Bacterial Meningtis and Focal CNS Infections
INDICATION:
Hospital-acquired meningitis, posttraumatic or postneurosurgery meningitis, neutropenic atients, or patients with impaired cell-mediated immunity
Ampicillin + ceftazidime, ceftriaxone
or
meropenem + vancomycin
antibiotic of choice for susceptible strains
-Penicillin G
Antibiotic for penicillin resistant strains
-Ceftriaxone or Cefotaxime
days IV antibiotic therapy is adequate for uncomplicated Meningococcal Meningitis
7 days
Chemoprophylaxis which through by Close contacts: individuals who have had =contact — with oropharyngeal
secretions, either through kissing or by sharing toys, beverages, or cigarettes.: 2 day regimen of
Rifampin
alternative treatment for adults having Meningococcal Meningitis
-One dose Azithromycin (SOOmg) or Ceftriaxone IM (250mg)
- Pneumococcal Meningitis Antibiotic Use
- ## week course of IV antimicrobial therapy is recommended
Cephalosporins and Vancomycin
strains of S. pneumoniae meningitis should have a repeat LP performed ____ after the initiation of antimicrobial therapy to document sterilization of the CSF.
24-36 h
Patients with penicillin- and cephalosporin-resistant strains
of S. pneumoniae who do not respond to intravenous vancomycin alone may benefit from the addition of ____ vancomycin.
intraventricular
Specific Antimicrobial Therapy for Listeria Meningitis
Ampicillin: at least 3 weeks
added in critically ill patient (2mg/kg loading dose , then 7.5
mg/kg per day given every 8 h and adjusted for serum levels and renal) with Listeria Meningitis
Gentamicin
alternative in penicillin allergic patients with Listeria Meningitis
- trimethroprin + sulfamethoxazole
Specific Antimicrobial Therapy for Staphyloccocal Meningitis suspectible strains
Naficillin
DOC for MRSA and patient allergic to penicillin for Staphyloccocal Meningitis
Vancomycin
If the CSF is not sterilized after 48h of IV vancomycin, either
intraventricular or intrathecal vancomycin , ___ once daily can be added in treating Staphyloccocal Meningitis
20 mg
Specific Antimicrobial Therapy for Gram-Negative Bacillary Meningitis
3rd-Gen cephalosporins:
- Cefotaxime,
- Ceftriaxone
- Ceftazidime,
Tx for meningitis due to P. aeruginosa
Ceftazidime or Meropenem
course of intravenous antibiotic therapy is recommended for therapy for Gram-Negative Bacillary Meningitis
-3-week
- inhibits the synthesis of IL-1B and TNF-a at the level of mRNA
- decreases CSF outflow resistance
- Stabilize the blood-brain barrier
Dexamethasone
Started Adjunctive therapy ____ before, or not later than concurrent with, the first dose of antibiotics.
20 min
Emergency treatment of increased ICP:
- elevation of the patient’s head to 30-45S°
- intubation and hyperventilation (Paco2 25-30 mmHg)
- Mannitol
Highest Mortality rate causing BACTERIAL MENINGITIS
- S. pneumoniae - 20%
- L monocytogenes- 15%
- H influenza, N meningitidis, GBS- 3-7%
Risk of death from bacterial meningitis increases :
- decreased level of consciousness on admission
- onset of seizures within 24 h of admission
- signs of increased ICP
- young age (infancy) and age >SO
- the presence of comorbid conditions including shock and/or the need for mechanical ventilation
- delay in the initiation of treatment
Decreased CSF glucose concentration _____ and markedly increased CSF protein concentration ____ have been predictive of increased mortality and poorer outcomes in some series.
- (<2.2 mmol/L [<40 mg/dL])
- (>3 g/L [> 300 mg/dL])
Sequelae OF BACTERIAL MENINGITIS
- decreased intellectual function,
- memory impairment,
- seizures,
- hearing loss and dizziness, and
- gait disturbances.