Page 96 - 15Diarrhoeaandvomiting

Fluid management

GDG translation from evidence to recommendation

There was no definitive evidence on the optimum IV fluid regimen for the management of
hypovolaemic shock in the dehydrated child with gastroenteritis. However, there was widespread
consensus that whatever the cause of shock, a bolus of IV fluid should immediately be given. 97,106
Currently, the main focus of discussion regarding fluid administration in patients with shock is on
the optimal choice of fluid. This includes discussion of crystalloid versus colloid fluids, especially
in relation to septicaemic or critically ill patients. The use of albumin solutions in particular is
controversial. 107–109 The GDG considered that for children with shock due to dehydration from
gastroenteritis, 0.9% sodium chloride solution is an appropriate and readily available fluid for
bolus administration.
In hypovolaemic shock associated with gastroenteritis, rapid recovery would be expected in most
children following the administration of a 20 ml/kg bolus of 0.9% sodium chloride solution. 97,106
If an immediate response does not occur, a further 20 ml/kg bolus should be given. In the absence
of prompt response to bolus fluid administration, it is important to consider whether factors other
than hypovolaemia, for example septicaemia, might be responsible. In this case, expert advice
should be sought from a paediatric intensive care specialist.

With regard to the treatment of dehydration (as opposed to shock) with IVT, the GDG recognised
that there was a lack of evidence from clinical trials to inform practice in this area. For example,
the WHO recommends the use of Ringer’s lactate solution for IV rehydration. There has been
much discussion on the optimal choice of IV maintenance fluids for children, particularly since
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the National Patient Safety Agency (NPSA) issued a specific alert on this matter in 2007. The
NPSA alert reinforced an existing trend away from the use of hypotonic solutions such as 0.18%
sodium chloride. This reflected concerns about the risk of hyponatraemia. 111
The NPSA has recommended the use of isotonic solutions such as 0.9% sodium chloride
with or without 5% glucose for children with a range of conditions associated with a risk of
hyponatraemia, including those with diarrhoea. There has been some controversy regarding the
NPSA recommendations. The use of 0.9% sodium chloride solution provides more salt to the
child than is to be found in an average diet. It appears that most children do not experience
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adverse effects with this increased salt load, but some may do. Concern has been expressed at a
possible risk of hypernatraemia and hyperchloraemic acidosis. However, because gastroenteritis
is associated with increased salt losses, the use of 0.9% sodium chloride solution in these children
has not been challenged. Furthermore, the NPSA recommendations emphasise the importance of
careful monitoring of plasma electrolytes during IVT.
The GDG agreed with the NPSA recommendations on this matter. The GDG also considered that
it was important for clinicians to be aware that metabolic acidosis might not be due to persisting
shock. Such misinterpretation could lead to the administration of excessive fluid. 113
As discussed earlier in relation to ORT, there is usually no precise way of determining the exact
fluid deficit and hence the required replacement volume. If a child is considered to be in a
state of hypovolaemic shock, their intravascular volume has been significantly depleted owing to
fluid loss. To reach this stage, it is generally accepted that they are at least 10% dehydrated, i.e.
they will have lost at least 100 ml/kg of total body fluid. The GDG agreed that once shock was
corrected with fluid bolus administration, it was safest to assume that the child might be 10%
dehydrated and they should therefore receive 100 ml/kg as deficit replacement.
For those who are dehydrated but without shock, in keeping with the recommendation for ORT, a
volume of 50 ml/kg IV was considered by the GDG to be an appropriate initial deficit replacement
volume. Regular reassessment would be necessary to determine whether this was sufficient to
reverse the signs of clinical dehydration. Further replacement would be given subsequently if this
was necessary.
The GDG was conscious of a lack of high-quality evidence regarding the optimal time period
over which IV fluids should be administered to children with dehydration. With ORT it is widely
accepted that rehydration can and should be completed quickly – typically over a 4 hour period.
Traditionally, IV rehydration has been performed over a 24 hour time period, and this approach is
still in common use. This practice probably evolved from experience with the use of subcutaneous
fluid replacement in children in the 1940s. The NPSA patient safety alert on IV infusions for
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