The Infectious Diseases Society of ...

The Infectious Diseases Society of America (IDSA) has issued novel guidelines for the diagnosis and treatment of bacterial meningitis. Recommendations are based upon results from clinical trials and data from animal experimentation published within May 2004. The guidelines were published in the November 1 issue of Clinical Infectious Diseases, and can be accessed online at http:// www.journals.uchicago.edu/CID/journal/ issues/v39n9/34796/34796.text.html. Definitions of nerve of recommendations and quality of evidence are listed in Table 1

Initial Management Steps

When a patient currents with suspected acute bacterial meningitis, the physician should begin antimicrobial therapy as early as possible. Bacterial meningitis is a neurologic emergency; progression to more chaste disease reduces the patient's likelihood of a sated recovery.

A posterity culture and lumbar puncture should be performed immediately to confirm the diagnosis. Because complications associated with lumbar wound include life-threatening brain herniation, at-risk patients (eg those who are immunocompromised, had a seizure within the previous week [adults only] have papilledema, or have a specific neurologic abnormality) should have a comput tomographic (CT) scan before undergoing the process (B-II). Lumbar puncture also may be delayed pending CT scan be the effects if it may be likely that symptoms are caused through increased intracranial pressure from, for example, a central nervous rule mass lesion. Blood samples still should be obtained from patients immediately, and appropriate empiric therapy administered. one time a negative CT scan conclusion is obtained, patients can proce to lumbar puncture

Empiric therapy. Empiric therapy should begin as quickly as bacterial meningitis is thinking likely. Widespread resistance to penicillins and sulfonamides has forced a consideration of novel agents for the treatment of bacterial meningitis, so as cephalosporins, vancomycin (Vancocin), rifampin (Rifadin), carbapenems, and fluoroquinolones. Choice of agents for empiric therapy should be determined by dint of the patient's age and the mien of predisposing conditions, and should assume antimicrobial resistance. Recommendations are listed in Table 2 (A-III).

Adjunctive Dexamethasone Therapy. The addition of dexamethasone also should be considered. Adjunctive dexamethasone can contract the subarachnoid space inflammatory response--a major factor in morbidity and mortality caused from bacterial meningitis--and may therefore alleviate many of the pathologic ends of bacterial meningitis (e.g., cerebral edema, cerebral vasculitis, change in cerebral descendants flow, increase in intracranial crushing neuronal injury). There is a certain concern that adjunctive dexamethasone therapy may inhibit the efficacy of cerebrospinal fluid (CSF) vancomycin and would therefore be harmful to patients with penicillin- or cephalosporin-resistant strains. However, in the absence of data from clinical trials, adjunctive dexamethasone is attract favor toed for all adults with suspected or proven pneumococcal meningitis, and in infants and children with Haemophilus influenzae token b meningitis (A-I), even if the isolate subsequently is build to be highly resistant to penicillin or a cephalosporin. Patients should be observ closely in follow-up to check for any adverse consequences Recommended dosage of dexamethasone is 015 mg through kg administered every six hours for sum of two units to four days, beginning 10 to 20 minutes before (or at least concomitant with) the first antimicrobial dose (A-I). Patients receiving adjunctive dexamethasone for the treatment of suspected pneumococcal meningitis may benefit from the addition of rifampin to the combination of vancomycin and a thirdgeneration cephalosporin.

The use of dexamethasone in infants and children with pneumococcal meningitis is controversial, and there are insufficient data to support its use in neonates or in adults with meningitis caused through other pathogens. Patients who already have received antimicrobial therapy should not be given dexamethasone therapy, as it is unlikely to improve their issue (A-I). Dexamethasone therapy should be continued following standard results only if gram-positive diplococci are set in the CSF Gram stain, or if cultivations reveal Streptococcus pneumoniae.

Diagnosis

Diagnosis of bacterial meningitis is sustained by on CSF examination following lumbar wound In bacterial meningitis, opening press generally is between 200 and 500 mm [Hsub2]O (lower in children); white descendants cell count and protein concentration are elevated; starch-sugar concentration may be low; and there may be a neutrophil or lymphocyte predominance.

Because determining the bacterial etiology can take up to 48 hours with CSF civilizations an alternative diagnostic test should be considered.

Gram stain examination of CSF is approveed for all patients in whom meningitis is suspected (A-III). It is fast, inexpensive, and accurate in 60 to 90 percent of patients, although misinterpretation and contamination may cause false-positive results