Correct fluid and electrolyte balance is essential to maintain physiological function. Normally, children and young people get the fluid they need by drinking. Many children and young people admitted to hospital may be too ill to drink so may need intravenous (IV) fluid therapy to correct or maintain their fluid and electrolyte balance.

Children and young people may need IV fluids to account for losses of red blood cells, plasma, water or electrolytes beyond the usual losses in urine, stools and sweat. These losses can come from burns, diarrhoea, vomiting or leakage of fluid into the interstitial space. In these cases the aim is to replace any depleted fluids and restore electrolyte balance. Conditions such as cardiac dysfunction, liver disease, inappropriate antidiuretic hormone secretion and nephrotic syndrome can result in an excess of fluids in the body, known as fluid overload. If this happens, the aim is to rebalance and redistribute fluids and ensure the correct levels of electrolytes.

Whether IV fluid therapy is needed for fluid resuscitation, routine maintenance, replacement or redistribution, it is vital that the correct composition, volume and timing of IV fluid therapy is used. IV fluid types include colloids, crystalloids and combinations of fluids, and different types of fluids are appropriate for different situations (see the MHRA Drug Safety Alert for hydroxyethyl starch intravenous infusions). Errors in prescribing or administering IV fluids can result in inadequate or excessive provision, leading to hypovolaemia and poor organ perfusion, or hypervolaemia, oedema and heart failure. Failing to correct imbalances in electrolytes can lead to disturbances in intracellular or extracellular electrolyte balance, particularly in children and young people with reduced liver or kidney function. Failing to deliver correct fluids can therefore have a significant impact on morbidity and mortality.

Surveys have shown that many staff who prescribe IV fluids know neither the likely fluid and electrolyte needs of individual patients, nor the specific composition of the many choices of IV fluids available to them. There is little formal training and education in IV fluid management to support correct prescribing.

There is also a wide variation in the charts used to prescribe fluids and to record fluid and electrolyte status. Monitoring children and young people is often challenging: it may be difficult to assess urine output accurately, and blood tests can be painful, distressing and difficult to repeat. Assessment and monitoring is often suboptimal, and fluid and electrolyte status may not be recorded accurately. Changes in patients' fluid needs may not be reassessed appropriately or at the correct intervals, which can lead to fluids being prescribed incorrectly. Clinical staff need to ensure that appropriate identification, treatment and monitoring of changes in fluid and electrolyte status is maintained and documented. There is a need for a standardised approach to assessing patients' fluid and electrolyte status and prescribing IV fluid therapy in the NHS. This guidance represents a major opportunity to improve patient safety for children and young people having IV fluid therapy in hospital.