The standard practice in paediatric departments in Danish hospitals is to prescribe hypotonic maintenance fluids (sodium content 20-40 mmol/l) for children, who are fasting or have a reduced enteral intake. The past decades have provided strong evidence, that this can lead to hypo-natraemia and subsequent neurologic damage or death. We recommend, that prefabricated isotonic solutions containing 140-154 mmol/l of sodium and 5% glucose, with or without an additional 20 mmol/l of potassium, are available as standard maintenance fluid for children in all Danish hospitals.