NICE-otonic fluids – making the switch to IV fluids containing normal saline

NICE-otonic fluids – making the switch to IV fluids containing normal saline

Key contacts

 Dr Andy Marshall (Paediatric Registrar); Apphia Bunting (Medical Student); Dr Rhiannon Furr (Paediatric Consultant)


NICE advises isotonic maintenance fluids as standard for all children, including most term neonates, due to evidence for hypotonic fluid-induced hyponatraemia. The limited local adoption of this guidance had been attributed, in part, to isolated cases of hypernatraemia in very small infants receiving isotonic fluids, whilst much of the relevant published evidence specifically excludes infants under 3 months.

SMART objectives

Local guidelines were updated and disseminated. A suitable range of isotonic fluids was made available on all wards in collaboration with pharmacy.

Fluid prescriptions were audited for infants under 3 months on paediatric wards, to quantify the extent of guideline uptake, and examine any associated electrolyte imbalances. Electronic record data (for medical and surgical patients, excluding neonatal units) were collected retrospectively for a 16-month period, including maintenance fluid prescriptions and biochemistry results.

Results were presented in paediatric, surgical and anaesthetic team meetings, and wider adoption of guidelines was facilitated through modifications to the electronic prescribing system.

The audit will be repeated to examine the current level of guideline uptake, and whether this has had impacts on electrolyte imbalance. Specifically, after 6 months, we will audit: the proportion of maintenance fluids which are hypotonic;  the number of patients with hypo- or hyper-natraemia, and whether these were associated with IV fluid administration.

 Progress made: What have you learned from doing this?

Audit over 16 months: Of 672 fluid prescriptions for infants under 3 months, 60% were hypotonic. Two cases of significant hyponatraemia  (<130 mmol/L) were associated with hypotonic fluid prescriptions. There were no cases of iatrogenic significant hypernatraemia (>150 mmol/L). 

Audit results were well received by all teams. An application was successfully made through IT and pharmacy to modify the electronic prescription system to promote isotonic solutions as standard for all patients. 

What’s your take home message?

 An audit of NICE IV fluid guideline uptake was successful in quantifying the degree of guideline adherence, and may have helped shift local practice.

If guideline adherence has now improved, a re-audit could further reassure clinicians of the safety of 0.9% saline in small infants.


Balasubramanian, Karthik, et al. “Isotonic versus hypotonic fluid supplementation in term neonates with severe hyperbilirubinemia–a double‐blind, randomized, controlled trial.” Acta Paediatrica 101.3 (2012): 236-241.

Moritz, Michael L., and Juan C. Ayus. “Intravenous fluid management for the acutely ill child.” Current opinion in pediatrics 23.2 (2011): 186-193.

National Patient Safety Agency (2007) Patient Safety Alert – Reducing the risk of hyponatraemia when administering intravenous infusions to children

McNab, Sarah, et al. “140 mmol/L of sodium versus 77 mmol/L of sodium in maintenance intravenous fluid therapy for children in hospital (PIMS): a randomised controlled double-blind trial.” The Lancet 385.9974 (2015): 1190-1197.

Choong, Karen, et al. “Hypotonic versus isotonic maintenance fluids after surgery for children: a randomized controlled trial.” Pediatrics 128.5 (2011): 857-866.

Wang, Jingjing, Erdi Xu, and Yanfeng Xiao. “Isotonic versus hypotonic maintenance IV fluids in hospitalized children: a meta-analysis.” Pediatrics(2013): peds-2013.