Page 88 - 15Diarrhoeaandvomiting

Fluid management

solution with 50–80 g/l of rice powder and all the other electrolyte concentrations remained
the same. Participants included both children and adults with signs of dehydration due to acute
diarrhoea. The outcomes reported were stool output during the first 24 hours, total stool output
(from admission to cessation of diarrhoea) and duration of diarrhoea. For studies in children, data
from girls were excluded owing to difficulty in measuring the stool volumes.

Of 22 hospital-based RCTs included for this review, 12 trials included children – five with cholera
and seven with non-cholera diarrhoea. Four of these trials were conducted in Bangladesh, two
in India, and one each in Indonesia, Pakistan, Mexico, Chile, Peru and Egypt. Two trials included
children younger than 6 months whereas the others included children above 4–6 months.
Allocation concealment was adequate in 15 of the 22 studies while the method of randomisation
and concealment was not reported in the remaining studies. None of the trials reported whether
patients with severe dehydration were randomised or whether outcome measurement started
before or after initial IVT. In six trials, 1–15% of randomised patients were excluded from the
final analysis, but these patients should have continued to be monitored and their data included
using intention-to-treat analysis. Outcomes were analysed separately for children with cholera
and non-cholera diarrhoea. [EL = 1++]
Twelve studies (n = 2854) reported the duration of diarrhoea for children younger than 5 years
suffering from non-cholera diarrhoea. Results from the meta-analysis suggest that children
receiving rice-based ORS solution had shorter duration of diarrhoea compared with those
receiving the glucose-based ORS solution, but the difference was not statistically significant
(WMD −1.26 days; 95% CI −4.4 to 1.9 days). There were also no statistically significant differences
between the two types of ORS solution for the outcomes of stool output in the first 24 hours of the
intervention (15 trials; WMD −4.3 g/kg; 95% CI −9.4 to 0.8 g/kg) or total stool output (nine trials;
WMD −28.2 g/kg; 95% CI −52.4 to 3.9 g/kg). For children with cholera, a significant reduction
in the 24 hour stool output was seen with rice-based ORS solution (four trials; WMD −67.4 g/kg;
95% CI −94.3 to −40.5 g/kg). Only one trial (n = 48) reported total stool output and duration of
diarrhoea in children with cholera and that showed a significant decrease in both outcomes with
the use of rice-based ORS solution.

Evidence summary
There is evidence from one high-quality systematic review [EL = 1++] indicating a significant
reduction in the need for unscheduled IV fluids for the treatment of dehydration in children with
diarrhoea when using low-osmolarity ORS solution compared with the previously recommended
high-osmolarity WHO ORS solution. Moreover, the results suggest that low-osmolarity ORS
solution leads to a greater reduction in stool output and vomiting. No difference was seen in
the incidence of hyponatraemia. The other systematic review [EL = 1+] reported no statistically
significant difference between ORS solutions with different sodium contents in terms of treatment
failure (need for IVT) in well-nourished children with gastroenteritis and dehydration. It also
failed to show any consistent trend in favour of either high- or low-sodium ORS solution for
rehydration.
Evidence from a well-conducted systematic review [EL = 1++] found no statistically significant
differences in stool output or duration of diarrhoea when children with non-cholera diarrhoea
were treated with rice-based ORS solution compared with the traditional glucose-based ORS
solution. However, in children with cholera, rice-based ORS solution was associated with a
reduction in stool output and duration of diarrhoea.

GDG translation from evidence to recommendation
ORS solution of reduced osmolarity (<270 mOsm/l) is preferable to solutions with a high
osmolarity (>311 mOsm/l). Reduced osmolarity ORS solution was associated with a lower
incidence of failure to rehydrate and also a greater reduction in stool output.

The original (pre-2002) WHO ORS solution had an intermediate osmolarity of 311 mOsm/l and
a sodium concentration of 90 mmol/l. In 2002, the WHO recommended a new ORS solution
formulation of lower osmolarity and sodium concentration (245 mOsm/l and 75 mmol/l,
respectively). This is closer in composition to the ORS solution products commonly used in the
UK (sodium concentrations 50–60 mmol/l, osmolarities 240–250 mOsm/l; see Table 5.1).

63