Fluid therapy for acute bacterial meningitis

Acute bacterial meningitis remains a disease with high mortality and morbidity rates. However, with prompt and adequate antimicrobial and supportive treatment, the chances for survival have improved, especially in infants and children. Careful management of fluid and electrolyte balance is an important supportive therapy. Both over- and under-hydration are associated with adverse outcomes.

To evaluate differing volumes of fluid given in the initial management of bacterial meningitis.

We searched the Cochrane Acute Respiratory Infection Group's trials register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to March 2007), EMBASE (1980 to March 2007), and CINAHL (1982 to February 2007).

Randomised controlled trials of differing volumes of fluid given in the initial management of bacterial meningitis were eligible for inclusion.

Six trials were identified in the initial search. On careful inspection three of these met the inclusion criteria. Data were extracted and trials were assessed for quality by all four of the original review authors (one author, R.O.W. has died since the original review, see acknowledgements). Data were combined for meta-analysis using relative risks for dichotomous data or weighted mean difference for continuous data. A fixed-effect statistical model was used.

The largest of the three trials was conducted in settings with high mortality rates. The meta-analysis found no significant difference between the maintenance-fluid and restricted-fluid groups in number of deaths (RR 0.82, 95% CI 0.53 to 1.27); acute severe neurological sequelae (RR 0.67, 95% CI 0.41 to 1.08); or in mild to moderate sequelae (RR 1.24, 95% CI 0.58 to 2.65). However, when neurological sequelae were defined further, there was a statistically significant difference in favour of the maintenance-fluid group in regard to spasticity (RR 0.50, 95% CI 0.27 to 0.93), seizures at both 72 hours (RR 0.59, 95% CI 0.42 to 0.83) and 14 days (RR 0.19, 95% CI 0.04 to 0.88), and chronic severe neurological sequelae at three-months follow up (RR 0.42, 95% CI 0.20 to 0.89).

Some evidence supports maintaining intravenous fluids rather than restricted them in the first 48 hours, in settings with high mortality rates and where patients present late. However, where children present early and mortality rates are lower there is insufficient evidence to guide practice.