Oral rehydration solution (ORS) has reduced childhood deaths from diarrhoea in many countries. Recent studies suggest that the currently recommended formulation of ORS recommended by the World Health Organization (WHO) may not be optimal, and solutions that contain lower concentrations of sodium and glucose may be more effective.
In children with acute diarrhoea, to compare reduced osmolarity glucose-based oral rehydration salt solution with international WHO formulation.
The Cochrane Collaboration Trials Register, MEDLINE, and EMBASE were searched. Additional trials were identified by hand searching. Content experts were contacted.
Randomised controlled trials comparing reduced osmolarity ORS solution with the WHO formulation. Outcomes sought were unscheduled intravenous fluid infusion therapy and measures of clinical illness.
Data were extracted by two reviewers. We tested for heterogeneity using the chi-square statistic, conducted sensitivity analysis by allocation concealment, and the regression approach to assess funnel plot asymmetry from selective trial publication.
The primary outcome was reported in 12 trials. In a meta-analysis of nine trials, reduced osmolarity ORS was associated with fewer unscheduled infusions compared with standard WHO ORS (Mantel Haenzel odds ratio 0.61, 95% confidence interval 0.47 to 0.81) with no evidence for heterogeneity between trials. No unscheduled intravenous fluid infusion therapy was required in any participant in three trials. Thirteen trials reported stool output, and data suggested less stool output in the reduced osmolarity ORS group. Vomiting was less frequent in the reduced osmolarity group in the six trials reporting this. Six trials sought hyponatraemia, with events in three studies, but no obvious difference between the two arms.
In children admitted to hospital with diarrhoea, reduced osmolarity ORS when compared to WHO ORS is associated with fewer unscheduled intravenous infusions, smaller stool volume post randomisation, and less vomiting. No additional risk of developing hyponatraemia when compared with WHO ORS was detected.