Page 130 - 15Diarrhoeaandvomiting

Other therapies

• IV metoclopramide versus placebo
• IV dexamethasone versus placebo.
The outcomes considered were duration of the disease (vomiting and diarrhoea outcomes),
tolerance of ORT, need for IVT, dehydration status and hospitalisation. Follow-up, treatment
protocol and definition criteria for inclusion of the children with gastroenteritis varied between
the three studies.
The first of the trials conducted in the USA 164 had two treatment arms and recruited children aged
6 months to 12 years with gastroenteritis presenting to a paediatric emergency department with
at least five episodes of vomiting in the preceding 24 hours and who had not received an anti-
emetic (n = 145). Those with an underlying chronic condition, possible appendicitis, a urinary
tract infection or who had severe gastroenteritis requiring immediate IV fluids were excluded.
Children were randomised to treatment with three doses (appropriate for age group) of oral
ondansetron (n = 74) or placebo (n = 71) per day. The methods of randomisation were adequate
and patients and outcome assessors were blind to treatment allocation. The power calculation
presented estimated that for a treatment success rate of 80% in the ondansetron group and 60% in
the placebo group, a sample size of 91 per group would be required. Outcomes measured were
cessation of vomiting during the stay in the emergency department, the need for IV rehydration,
hospitalisation and diarrhoeal episodes during follow-up. [EL = 1+]

The groups were similar at baseline for age, sex and severity of illness. No children were
lost to follow-up in the emergency department stay, but by 48 hours 32/145 had been lost.
More children in the ondansetron group (64/74) stopped vomiting in the first few hours after
treatment in the emergency department compared with those who received placebo (46/71).
This difference was statistically significant (RR 1.33; 95% CI 1.10 to 1.62). Fewer children treated
with oral ondansetron required IVT (8% estimated from histogram) or were admitted to hospital
(2/74) compared with those treated with placebo (22.5% and 11/71, respectively) (RR 0.42;
95% CI 0.17 to 1.00 and RR 0.15; 95% CI 0.03 to 0.71, respectively). The mean number of
diarrhoeal episodes while undergoing rehydration (mean length of stay in emergency department
106 minutes ondansetron group versus 120 minutes placebo group) was statistically significantly
higher in children who had received ondansetron (mean 1.40) compared with the placebo group
(mean 0.50) (P < 0.001) even after adjustment for number of episodes prior to admission.
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The second US trial recruited children aged 6 months to 10 years presenting to an emergency
department with gastroenteritis (defined as at least one episode of vomiting within the 4 hours
preceding triage, at least one episode of diarrhoea and mild to moderate dehydration) (n = 215).
Those with a body weight less than 8 kg, severe dehydration, an underlying disease that could
affect the assessment of dehydration, a history of abdominal surgery or hypersensitivity to
ondansetron were excluded. Participants were randomised to treatment with oral ondansetron
(dose appropriate for age group) (n = 108) or placebo (n = 107). The methods of randomisation
were adequate and treatments were given by a bedside nurse such that the patient, caregivers
and outcome assessors were blinded to allocation. The proportion of patients randomised but lost
to follow-up was less than 20%. The power calculation presented estimated that to provide the
study with a statistical power of 90% to detect a change from 35% in the placebo group to 15%
in the treatment group (in the children who vomited during ORT) (type I error 0.05), 215 children
would need to be recruited. The primary outcome was the proportion of children who vomited
while receiving ORT and the secondary outcomes were episodes of vomiting during ORT, rate of
IV rehydration, rate of hospitalisation and diarrhoeal episodes during follow-up (on days 3 and 7
after randomisation). [EL = 1+]
The two groups were comparable at baseline for sex, age, weight, heart rate, dehydration
score, the number of vomiting and diarrhoeal episodes prior to presentation, and serum values.
Statistically significantly more children in the ondansetron group (92/107) stopped vomiting in
the first few hours after treatment compared with those who received placebo (70/107) (RR 1.31;
95% CI 1.12 to 1.54). Fewer of the children receiving ondansetron required IVT (15/107) than
those treated with placebo (33/107), the difference being statistically significant (RR 0.45; 95% CI
0.26 to 0.79). There were no statistically significant differences between groups in the numbers
of children admitted to hospital or in episodes of diarrhoea while undergoing rehydration (mean
length of stay in emergency department 2 hours ondansetron group versus 3 hours placebo
group). However, over the next 48 hours, children receiving ondansetron had statistically

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