Page 94 - 15Diarrhoeaandvomiting

Fluid management

Clinical questions
During rehydration with IVT, how much fluid is required, and how quickly should it be given?
Is there a place for ‘rapid rehydration therapy’?
No study was identified that provided direct evidence on the volume of deficit or the duration
over which IV rehydration should be performed. For the second part of the question, three papers
were identified.

Evidence overview
All three studies considered the role of ‘rapid rehydration therapy’ or delivering fluid deficit
replacement over a short period of time in children with severe dehydration (without shock) who
were unable to tolerate oral fluids.
The first was a prospective study with historical controls conducted in Australia 103 to evaluate the
effectiveness of rapid rehydration with IV fluid or with ORT (administered through nasogastric
tube) in the treatment of moderately dehydrated children. Inclusion criteria were age 6 months
to 16 years, duration of illness less than 48 hours, presence of vomiting and diarrhoea with mild
to moderate dehydration, normal respiratory rate and level of consciousness, and a CRT of less
than 2 seconds. All the participants were initially given a trial of oral fluids using Gastrolyte-R®
or apple juice diluted to 25% (2.5 g carbohydrate, 1.25 mg sodium, 20 mg potassium) if
the former was refused. Parents were educated by nurses on the importance of initial oral
rehydration. Moderately dehydrated children who were unable to tolerate 100 ml of oral fluid
over 1 hour (50 ml for children younger than 2 years) were given rapid rehydration. The options
for administration were intravenously using N/2 saline + 2.5% dextrose over 2 hours at 20 ml/kg
per hour or by nasogastric tube with Gastrolyte-R at the same rate. Following rapid rehydration,
children were given another trial of 100 ml of oral fluid (50 ml for children younger than 2 years)
over 1 hour. Children who tolerated and satisfied the discharge criteria were discharged while
those not tolerating orally were admitted to the hospital to continue rehydration. The historical
control group was made of children admitted 2 years earlier in the same hospital with a similar
diagnosis, and their hospital records were checked for data collection. These children were given
a non-standard regimen of initial oral fluid trial, failing which they were rehydrated intravenously
over a period of 24 hours. There was no specific education on oral fluid therapy geared towards
parents and volume of fluid intake was estimated from parents’ reports. Outcomes reported
were admission to hospital, discharge in 8 hours or less after presentation to the emergency
department and re-presentation requiring admission within 48 hours of discharge from the
emergency department. The outcomes were measured for moderately dehydrated patients as well
as for mildly dehydrated patients. Patients having rehydration via the IV route or the nasogastric
tube route were analysed together. [EL = 2−]

In this study, 145 patients were recruited in the intervention group (rapid rehydration therapy)
and 170 in the control group (IV rehydration over 24 hours). The two groups were similar with
regard to age and sex but the intervention group had recruited significantly more moderately
dehydrated children. On comparing moderately dehydrated patients only between the two
groups, a statistically significant reduction was observed in the hospital admission rates in the
intervention group compared with the control group (55.8% versus 96.3%; P < 0.001). Moreover,
significantly more patients in the intervention group were discharged at 8 hours or less after
presentation to the emergency department (44.2% versus 3.7%; P < 0.001). No statistically
significant difference was seen for rates of re-presentation requiring admission within 48 hours
of discharge from the emergency department. For mildly dehydrated patients in the two groups,
no statistically significant difference was seen for the above outcomes. In the intervention group,
electrolytes were analysed for 78 children and 17 were found to be hyponatraemic on initial
assessment. Two of these patients presented with serum sodium levels < 130 mmol/l (128 and
125 mmol/l). However, they did not suffer from any complications or clinical sequelae and their
serum sodium levels returned to normal levels by 12 hours.
The second study was a prospective cohort study from the USA 104 that evaluated the efficacy of
rapid IV rehydration in children with mild to moderate dehydration due to gastroenteritis in the
hospital outpatient department. The criteria for inclusion were age at least 6 months, clinical
diagnosis of acute gastroenteritis with exclusion of other causes, vomiting for less than 48 hours

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