Polymer-based oral rehydration solution for treating acute watery diarrhoea.

Background: Acute diarrhoea is one of the principal causes of morbidity and mortality among children in low-income countries. Glucose-based ORS helps replace fluid and prevent further dehydration from acute diarrhoea. Since 2004, the World Health Organization has recommended the osmolarity < 270 mOsm/L (ORS </= 270 ) over the > 310 mOsm/L formulation (ORS >/= 310). Glucose polymer-based ORS (eg prepared using rice or wheat) slowly releases glucose and may be superior.
Objectives: To compare polymer-based ORS with glucose-based ORS for treating acute watery diarrhoea.
Search Strategy: In September 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, LILACS, and mRCT. We also contacted researchers, organizations, and pharmaceutical companies, and searched reference lists.
Selection Criteria: Randomized controlled trials of people with acute watery diarrhoea (cholera and non-cholera associated) comparing polymer-based and glucose-based ORS (with identical electrolyte contents).
Data Collection and Analysis: Two authors independently assessed the search results and risk of bias, and extracted data. In multiple treatment arms with two or more treatment groups, we combined outcomes as appropriate and compared collectively with the control group.
Main Results: Thirty-four trials involving 4214 participants met the inclusion criteria: 27 in children, five in adults and two in both. Twelve trials used adequate methods to conceal allocation. Most compared polymer-based ORS with ORS >/= 310. There were fewer unscheduled intravenous infusions in the polymer-based ORS group compared with glucose-based ORS (ORS >/= 310 and </= 270 groups combined) (RR 0.75, 95% CI 0.59 to 0.95; 2235 participants, 19 trials). Adults positive for Vibrio cholerae had a shorter duration of diarrhoea with polymer-based ORS than with ORS </= 270 (MD -7.11 hours, SD -11.91 to -2.32; 228 participants, 4 trials). Wheat-based ORS resulted in lower total stool output in the first 24 hours compared with ORS </= 270 (MD -119.85 g/kg, SD -114.73 to -124.97; 129 participants, 2 trials). Adverse effects were similar for polymer-based ORS and glucose-based ORS.
Authors' Conclusions: Polymer-based ORS shows some advantages compared to ORS >/= 310 for treating all-cause diarrhoea, and in diarrhoea caused by cholera. Comparisons favoured the polymer-based ORS over ORS </= 270, but the analysis was underpowered. If specialists consider a potential role for polymer-based ORS, further trials against the current standard (ORS </= 270) will be required.