Treatment of bacterial meningitis focuses on sterilization of the CSF by antibiotics (Table 100–3) and maintenance of (0–28 days) ceftriaxone plus gentamicin ampicillin with or Ceftazidime plus without gentamicin ampicillin adequate cerebral and systemic perfusion. Due to increasing
S. pneumoniae resistance to penicillin and cephalosporins, empirical cefotaxime (or ceftriaxone) plus vancomycin should be administered until antibiotic susceptibility testing is available. Cefotaxime or ceftriaxone are also adequate to treat
N. meningitidis and H. influenzae. For infants younger than 2 months of age, ampicillin is added to cover the possibility of Listeria monocytogenes. Duration of treatment is 5 to 7 days for N. meningitidis, 7 to 10 days for H. influenzae, and 10 to 14 days for S. pneumoniae.
Dexamethasone (0.6 to 0.8 mg/kg daily in two to three divided doses for 2 days), as adjunctive therapy initiated just before or concurrently with the first dose of antibiotics, significantly diminishes the incidence of hearing loss and neurologic deficits resulting from H. influenzae meningitis. Adjuvant steroids do not appear to decrease mortality or hospital stay in studies in the developed world.
Supportive therapy involves treatment of dehydration, shock, disseminated intravascular coagulation, syndrome of inappropriate antidiuretic hormone (SIADH), seizures, increased intracranial pressure, apnea, arrhythmias, and coma. Adequate cerebral perfusion must be maintained in the presence of cerebral edema.
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SIADH may complicate meningitis and necessitates monitoring of urine output and fluid administration. Computed tomography or magnetic resonance imaging commonly detects subdural effusions with S. pneumoniae and H. influenzae meningitis. Most effusions are sterile and asymptomatic and do not necessitate drainage unless associated with increased intracranial pressure or focal neurologic signs. Persistent fever is common during treatment but also may be related to infective treatment or immune complex-mediated pericardial or joint effusions, thrombophlebitis, drug fever, or nosocomial infection. A repeat lumbar puncture after 48 hours of therapy should be considered for those whose condition has not improved or has worsened and for those who received adjunct steroids, which can interfere with the ability to monitor clinical response.
Even with appropriate antibiotic therapy, the mortality rate for bacterial meningitis in children is significant: 25% for
S. pneumoniae, 15% for N. meningitidis, and 8% for H. influenzae. Of survivors, 35% have sequelae, particularly after pneumococcal infection, including deafness, seizures, learning disabilities, blindness, paresis, ataxia, or hydrocephalus. All patients with meningitis should have a hearing evaluation before discharge and at follow-up. Poor prognosis is associated with young age, long duration of illness before effective antibiotic therapy, seizures, coma at presentation, shock, low or absent CSF white blood cell count in the presence of visible bacteria on CSF Gram stain, and immunocompromised status.
Rarely relapse may occur 3 to 14 days after treatment, possibly from parameningeal foci or resistant organisms. Recurrence may indicate an underlying immunologic or anatomic defect that predisposes the patient to meningitis.