title: Meta-analysis of studies comparing adjuvant dexamethasone to glycerol to improve clinical outcome of bacterial meningitis.
abstract: BACKGROUND
  Neurological complications are a problematic factor in acute bacterial meningitis; hence, its prevention is the key to ensure the success of meningitis treatment. Glycerol and dexamethasone are both applied in this regard. Oral glycerol is an appropriate alternative instead of intravenous dexamethasone because it does not have problems related to intravenous injection, the high cost, and drug complications. The main objective of this study was to compare the efficacy of adjuvant dexamethasone versus glycerol in order to improve the clinical outcome of bacterial meningitis.
  
  
  METHODS
  We conducted a search on the available resources including PubMed, Ovid, Elsevier, Cochrane, and another search engines such as Google till 2014. All clinical trials that were performed in the field of comparing the effectiveness of the two drugs and met the inclusion criteria were gathered and after extraction the relative risk (RR) values, the pooled RR was calculated. The main outcome was neurological complications. Meta-analysis of the data was performed in Stata version 11.2 using both fixed and random effect models, weighting each study by inverse of variance.
  
  
  RESULTS
  In 5 comparative studies (1,340 patients), the rate of neurological complications of glycerol compared to that of dexamethasone was 1.02 [95% confidence interval (CI), 0.98 compared to 1.12]. The rate of neurological complications of dexamethasone compared to dexamethasone + glycerol was 1 (95% CI, 0.97 compared to 1.03), dexamethasone compared to placebo was 0.99 (95% CI, 0.97 compared to 1.03), glycerol compared to glycerol + dexamethasone was 0.98 (95% CI, 0.94 compared to 1.02), and glycerol compared to placebo was 0.97 (95% CI, 0.94 compared to 1.01). In these studies, no difference was reported between dexamethasone and glycerol in terms of reducing neurological complications.
  
  
  CONCLUSIONS
  Although there were some weak evidences for the nonstatistical significant effect of glycerol in the prevention of neurologic complication after meningitis, there was no difference between glycerol and dexamethasone.
authors.affiliation: Department of Infectious and Tropical Disease, School of Medicine, Kermanshah, Iran.
authors.forename: Siavash
authors.initials: S
authors.lastname: Vaziri
authors.affiliation: Department of Infectious and Tropical Disease, School of Medicine, Kermanshah, Iran.
authors.forename: Fiezollah
authors.initials: F
authors.lastname: Mansouri
authors.affiliation: Department of Infectious and Tropical Disease, School of Medicine, Kermanshah, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Sayad
authors.affiliation: Department of Infectious and Tropical Disease, School of Medicine, Kermanshah, Iran.
authors.forename: Keyghobad
authors.initials: K
authors.lastname: Ghadiri
authors.affiliation: Department of Infectious and Tropical Disease, School of Medicine, Kermanshah, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Torkashvand
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Mansour
authors.initials: M
authors.lastname: Rezaei
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Farid
authors.initials: F
authors.lastname: Najafi
authors.affiliation: Department of Medical Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Azizi
keywords: Dexamethasone; glycerol; meningitis; neurological complications