akinohanayuki ブログ

学位を持っても、センスのない、感染制御専門薬剤師のブログ.  I have Ph.D. but less sense ID pharmacist.

細菌性髄膜炎

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細菌性髄膜炎
 
今日も遭遇しました。
 
ステロイド、抗菌薬の併用、髄糖、血糖など、確認事項が多いですよね。
 
復習です。
 
UpToDate 

 

General approach
 
Bacterial meningitis is a medical emergency, and immediate steps must be taken to establish the specific cause and initiate effective therapy. The mortality rate of untreated disease approaches 100 percent and, even with optimal therapy, there is a high failure rate.
 
If possible, crucial historical information (eg, serious drug allergies, recent exposure to an individual with meningitis) should be obtained before antibiotic treatment of presumed bacterial meningitis is instituted.
 
Initial blood tests should include two sets of blood cultures. The initial approach to management in a patient with suspected bacterial meningitis includes performance of a lumbar puncture (LP) to determine whether the cerebrospinal fluid (CSF) findings are consistent with the diagnosis.
 
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There are three general requirements of antimicrobial therapy for bacterial meningitis: use of bactericidal drugs effective against the infecting organism, use of drugs that enter the CSF, and use of drugs with optimal pharmacodynamics.
 
We recommend that antimicrobial therapy be initiated immediately after the performance of the lumbar puncture or, if a computed tomography (CT) scan is to be performed before LP, immediately after blood cultures are obtained (Grade 1B). Adjunctive dexamethasone should be given shortly before or at the same time as the first dose of antibiotics, when indicated.
 
For adults in the developed world with suspected bacterial meningitis in whom the organism is unknown or Streptococcus pneumoniae is confirmed, we recommend administration of dexamethasone (Grade 1B). Dexamethasone should be continued if the CSF Gram stain and/or the CSF or blood cultures reveal S. pneumoniae. Rifampin is added to the regimen in patients receiving dexamethasone under certain circumstances. 
 
Once the CSF Gram stain results are available, the antimicrobial regimen should be tailored to cover the most likely pathogen. If the CSF findings are consistent with the diagnosis of acute bacterial meningitis but the Gram stain is negative, empiric antibiotic therapy should be continued.
 
The antibiotic regimen should be modified further, when indicated, based on the CSF culture and susceptibility results.
 
Empiric antimicrobial therapy
 
Antimicrobial selection must be empiric immediately after CSF is obtained or when lumbar puncture is delayed. The empiric approach to antimicrobial selection in patients with suspected bacterial meningitis is directed at the most likely bacteria based on the patient's age and underlying disease status. 
 
  • No known immunodeficiency
 
S. pneumoniae, Neisseria meningitidis, and, less often, Haemophilus influenzae and group B Streptococcus are the most likely causes of community-acquired bacterial meningitis in otherwise healthy adults up to the age of 60. Individuals aged over 50 years are also at substantial risk of Listeria monocytogenes meningitis. Patients without known immune deficiency and with normal renal function should be treated empirically with the following regimen until culture and susceptibility data are available 
 
Ceftriaxone – 2 g intravenously (IV) every 12 hours
or
Cefotaxime – 2 g IV every 4 to 6 hours
plus
Vancomycin – 15 to 20 mg/kg IV every 8 to 12 hours (not to exceed 2 g per dose or a total daily dose of 60 mg/kg; adjust dose to achieve vancomycin serum trough concentrations of 15 to 20 mcg/mL)
plus
•In adults >50 years of age, ampicillin – 2 g IV every four hours
 
  • Impaired cell-mediated immunity
 
●Among patients with impaired cell-mediated immunity (due, for example, to lymphoma, cytotoxic chemotherapy, or high-dose glucocorticoids), coverage must be directed against L. monocytogenes and gram-negative bacilli (including Pseudomonas aeruginosa) as well as S. pneumoniae. An appropriate regimen in patients with normal renal function is 
 
Vancomycin – 15 to 20 mg/kg IV every 8 to 12 hours (not to exceed 2 g per dose or a total daily dose of 60 mg/kg; adjust dose to achieve vancomycin serum trough concentrations of 15 to 20 mcg/mL)
plus
Ampicillin – 2 g IV every 4 hours
plus either
Cefepime – 2 g IV every 8 hours
or
Meropenem – 2 g IV every 8 hours
 
  • Healthcare-associated meningitis
 
Empiric therapy for healthcare-associated meningitis must cover both gram-positive and gram-negative (such as Klebsiella pneumoniae and P. aeruginosa) pathogens. An appropriate regimen in patients with normal renal function is:
Vancomycin – 15 to 20 mg/kg IV every 8 to 12 hours (not to exceed 2 g per dose or a total daily dose of 60 mg/kg; adjust dose to achieve vancomycin serum trough concentrations of 15 to 20 mcg/mL)
plus
Ceftazidime – 2 g IV every 8 hours
or
Cefepime – 2 g IV every 8 hours
or
Meropenem – 2 g IV every 8 hours
 
  • Allergy to beta-lactams
 
For empiric coverage in patients with severe beta-lactam allergies and normal renal function, we suggest (Grade 2C):
Vancomycin – 15 to 20 mg/kg IV every 8 to 12 hours (not to exceed 2 g per dose or a total daily dose of 60 mg/kg; adjust dose to achieve vancomycin serum trough concentrations of 15 to 20 mcg/mL)
plus
Moxifloxacin – 400 mg IV once daily
plus
•If Listeria coverage is required (in patients >50 years of age and/or in those with defects in cell-mediated immunity), trimethoprim-sulfamethoxazole – 5 mg/kg (of the trimethoprim component) IV every 6 to 12 hours
 
For the initial therapy of S. pneumoniae, we recommend vancomycin plus either ceftriaxone or cefotaxime rather than a third-generation cephalosporin alone (Grade 1B).
 
If the isolate is proven to be susceptible to penicillin (minimum inhibitory concentration [MIC] ≤0.06 mcg/mL), monotherapy with penicillin G or ampicillin can be used. It is also reasonable to continue therapy with a third-generation cephalosporin alone instead of changing to penicillin or ampicillin, given the excellent efficacy, convenient dosing, and affordability of these agents.
 
If the isolate is resistant to penicillin (MIC ≥0.12 mcg/mL), but susceptible to third-generation cephalosporins (MIC <1.0 mcg/mL), either cefotaxime or ceftriaxone should be used. However, if the isolate is resistant to both penicillin and third-generation cephalosporins, vancomycin plus a third-generation cephalosporin should be continued for the total duration of therapy.
 
For the initial therapy of N. meningitidis, we recommend a third-generation cephalosporin, such as cefotaxime or ceftriaxone, rather than penicillin, while awaiting susceptibility data (Grade 1C). If the isolate is susceptible to penicillin, either a third-generation cephalosporin or penicillin may be used to complete the course of therapy.