Dexamethasone treatment for acute bacterial meningitis: how strong is the evidence for routine use?

A methodological appraisal of the published randomised controlled trials on the use of dexamethasone as an adjunct treatment in acute bacterial meningitis was carried out to examine whether the available evidence is strong enough to support the routine use of the drug. Studies were eligible for inclusion if they were published in indexed journals after 1966, written in English, and were randomised controlled trials with dexamethasone as adjunct to antimicrobials in patients with acute bacterial meningitis. All studies were extracted and their adherence to eight methodological principles was graded as adequate, inadequate, or unclear. A sensitivity analysis was done to examine the robustness of the conclusions. Seven studies met the eligibility criteria. No report adhered to all the principles. Major threats to validity of the conclusions included potential bias in analysis in all the studies, and lack of adjustment for baseline imbalances in four. Inadequate reporting of adverse effects hindered risk-benefit analysis. Sensitivity analysis showed that the numbers of patients withdrawn from analysis were enough to invalidate the conclusions. It is concluded that the available evidence is not strong enough to support a routine use of dexamethasone in acute bacterial meningitis. Further research is needed to determine the effect of a policy to use dexamethasone early in the management of suspected acute bacterial meningitis. Future studies should adopt a pragmatic approach, be methodologically rigorous, and meticulously measure the risk as well as the benefit of this policy.