Meningitis
-
Upload
mango91286 -
Category
Documents
-
view
214 -
download
2
Transcript of Meningitis
Bacterial meningitis: Causes, diagnosis, treatment, and prognosis
Mortality: 25% in community acquired acute bacterial meningitis o Associated with: >60 years old, obtunded mental status on
admission, onset of seizures within 24 hours of admission Complications: cognitive impairment, hearing loss, seizures,
hydrocephalus, visual deficits Classic triad of fever, nuchal rigidity, altered mental status: in less than
half of patients 95% of patients had at least 2 of: headache, fever, nuchal rigidity,
altered mental status Headache is most common Other symptoms: nausea, vomiting, photophobia, rash
(meningococcal) Kernig’s sign and Brudzinski’s sign not considered useful
diagnostically (5% sensitive, 95% specific) Nuchal rigidity: 30% sensitive, 68% specific Clinical features not consistentCauses
Diagnosis CSF: Gram stain and culture, cell count, glucose, protein
o CT in patients with: immunocompromise, papilledema, focal neurological deficits, CSF shunts, history of hydrocephalus, and/or trauma to prevent brain herniation (secondary to intracranial masses)
Two sets of blood cultures before initiation of antibiotics Blood lactic acid if recent neurosurgical procedure
o 4.0 mmol/L or more is consistent with bacterial meningitis instead of aseptic postsurgical meningitis
Latex agglutination: detects capsular polysaccharides of bacterial pathogens. For patients with negative CSF Gram stain from previous antibiotic use. High false positive rates.
PCR: 100% sensitive, 98.2% specific. Expensive, not widely available Other studies: CSF VDRL, CSF PCR for enteroviruses and herpesvirus,
CSF fungal stain, CSF mycobacterial stainTreatment If negative CSF Gram stains and cultures + high clinical suspicion
chose treatment based on host presentation
Penicillin minimum inhibitory concentration (MIC) <0.1 mg/mL penicillin G, ampicillin
Penicillin MIC 0.1-1 mg/mL third generation cephalosporin (ceftriaxone), cefepime, meropenem
Penicillin MIC >2.0 mg/mL vancomycin + third generation cephalosporin
Ceftriaxone MIC > 2mg/mL add rifampin Pneumococcal meningitis: dexamethasome (0.15 mg/kg every 6
hours) for the first 2-4 days. Only before and during first antibiotic dose. Decreases risk of adverse outcomes.
Meningococcal meningitis: respiratory isolation first 24 hours, prophylaxis for close contacts.
If patient does not improve in 48 hours, repeat LP. However, neck stiffness may persist up to 7 days.
Length of antiobiotic regimen: 7 days for N meningitides and H influenzae, 10-14 days for S pneumonia, 14-21 days for S agalactiae, 21 days for L monocytogenes or aerobic Gram negative bacilli