Bacterial Meningitis Medical Slides

Present data showing that each hour of antibiotic delay increases mortality by 3-7%. Teach the principle: if bacterial meningitis is suspected, administer empiric antibiotics immediately, even before CT or lumbar puncture if these will cause delay. Blood cultures drawn before antibiotics can still identify the organism in 50-70% of cases.

Create a comparison table of bacterial versus viral versus fungal versus TB meningitis showing WBC count and differential, glucose ratio (CSF/serum below 0.4 in bacterial), protein levels, and Gram stain yield. Emphasize that partially treated bacterial meningitis can mimic viral profiles, and that CSF lactate above 3.5 mmol/L has high specificity for bacterial etiology.

Administer dexamethasone 0.15 mg/kg IV before or with the first dose of antibiotics, continuing every 6 hours for 4 days. Present the de Gans 2002 trial showing reduced mortality and hearing loss in pneumococcal meningitis. Note the controversy: benefit is best demonstrated for Streptococcus pneumoniae in high-income settings, and some guidelines suggest discontinuing if a non-pneumococcal organism is identified.