Table 1.

Sliding-scale fluid prescription given to the parents to adjust daily fluid prescription according to the home blood sodium result

Blood Sodium (mmol/L)	Daily Fluid Prescription (mls)*
Below 130	100	Telephone and go to ED for assessment
130-134	500	Repeat sodium level before PM dose
135-139	800	Repeat sodium level before PM dose
140-145	1,200	Sodium is in target range
146-150	1,350	Repeat sodium level before PM dose
151-155	1,500	Repeat sodium level before PM dose
Over 155	1,800	Telephone and go to ED for assessment

Parents were instructed to telephone the Paediatric Endocrine department and attend the emergency department (ED) if levels were below 130 or over 150 mmol/L.

*The fluid prescription is based on 1,200 ml maintenance fluids, with additions or subtractions based on the formula for calculating water deficit in ml (600 × wt(kg) × (1-target [Na]/measured [Na]). If the sodium is >150 mmol/L, the extra fluid above maintenance has been reduced by 25% to avoid excessively rapid correction.