Abstract
Background
Oral rehydration solution (ORS) is used to treat the dehydration caused by diarrhoeal diseases, including cholera. ORS formulations with an osmolarity (a measure of solute concentration) of <= 270 mOsm/L (ORS <= 270) are safe and more effective than ORS formulations with an osmolarity of >= 310mOsm/L (ORS >= 310) for treating non-cholera diarrhoea. As cholera causes rapid electrolyte loss, it is important to know if these benefits are similar for people suffering fromcholera.
Objectives
To compare the safety and efficacy of ORS <= 270 with ORS >= 310 for treating dehydration due to cholera.
Search methods
We searched the Cochrane Infectious Disease Group Specialized Register (April 2011), CENTRAL (The Cochrane Library Issue 4, 2011), MEDLINE (1966 to April 2011), EMBASE (1974 to April 2011), and LILACS (1982 to April 2011). We also contacted organizations and searched reference lists.
Selection criteria
Randomized controlled trials comparing ORS <= 270 with ORS >= 310 for treating adults and children with acute diarrhoea due to cholera.
Data collection and analysis
Two reviewers independently applied eligibility criteria, assessed trial quality, and extracted data. We pooled dichotomous data using risk ratio (RR), pooled continuous data using mean difference (MD) or the standardized mean difference (SMD), and presented the results with 95% confidence intervals (CI).
Main results
For glucose-based ORS, seven trials (718 participants) met the inclusion criteria. Biochemical hyponatraemia (blood sodium levels < 130 mmol/L) was more common with ORS <== 270 (RR 1.67, CI 1.09 to 2.57; 465 participants, four trials), while a higher level of severe biochemical hyponatraemia (blood sodium levels < 125 mmol/L) in the same group was not significant (RR 1.58, CI 0.62 to 4.04; 465 participants, four trials). No instances of symptomatic hyponatraemia or death were noted in the trials that intended to record them. We found no statistically significant difference in the need for unscheduled intravenous infusion. Analyses separating children and adults showed no obvious trends. Two trials also examined rice-based ORS. In the ORS = 270 group, duration of diarrhoea was shorter (MD -11.42 hours, CI -13.80 to -9.04; 102 participants, two trials).