Purpose of review: Intravenous dexamethasone (DXM) is used as adjuvant medication in bacterial meningitis of childhood, although no single study has proven its efficacy against death, severe neurological sequelae, or hearing impairment. Meta-analyses do not facilitate interpretation, because they combine profoundly dissimilar populations and neglect the child's presenting condition. Important new information was revealed by a large double-blind, prospective study from Latin America in which the effects of oral glycerol (GLY) were compared with those of DXM.
Recent findings: Of 654 children, mainly with Haemophilus influenzae type b or pneumococcal meningitis, 166 received DXM, 159 DXM and GLY, 166 GLY, and 163 placebo. Neither of the adjuvants prevented hearing impairment, regardless of agent or timing of antibiotic. Instead of the causative agent, the presenting status was the only characteristic that associated with all three outcomes. GLY, but not DXM, prevented neurological sequelae, especially in Haemophilus influenzae type b meningitis. The likely mechanism of GLY is the increase in plasma osmolality. Cerebrospinal fluid genome counts differ enormously and predict death in pneumococcal but not Haemophilus influenzae type b meningitis.
Summary: Being the first adjuvant in childhood meningitis with documented clinically meaningful benefits, GLY seriously challenges the position of DXM as adjuvant medication. Severe neurological sequelae are relieved by GLY, whereas no current medication prevents hearing impairment.