• diabetic ketoacidosis
• diabetes
• fluid management
• cerebral oedema

Young people with insulin dependent diabetes mellitus are three times more likely to die in childhood than the general population.¹ Despite advances in management over the past 20 years, the incidence of mortality associated with diabetic ketoacidosis (DKA) remains unchanged. Cerebral oedema is the predominant cause of this mortality; young children are particularly at risk, with an incidence of 0.7–1% of episodes of DKA.^2,3 The mortality appears to be greatest among patients at first presentation,^1,3,4 if there has been a long history of symptoms prior to admission,³ and during the first 24 hours of treatment.⁴ In a recently published retrospective multicentre analysis of children with DKA, low pco₂ levels and high serum sodium concentration at presentation were identified as particular risk factors for the development of cerebral oedema, together with bicarbonate therapy.⁵ However, in the accompanying editorial, Dunger and Edge point out that this may simply be revealing an association between severe DKA and dehydration and the risk of cerebral oedema.⁶ The pathogenesis of cerebral oedema remains poorly understood but there may be many contributing factors.⁷

The aim of management of DKA is to restore metabolic homoeostasis while minimising the risks of complications including hypoglycaemia, hypokalaemia, cardiac failure, and in children the development of cerebral oedema. How best to achieve this remains contentious, with particular controversy centred on optimal fluid management. The most appropriate volume, type, and rate of fluid to be given have all been the subject of debate. A survey in 1994 of UK paediatricians found a threefold variation in the amount of fluid recommended within the first 12 hours.⁸ Since then national guidelines have been developed by the British Society for Paediatric Endocrinology (BSPE). However, it remains …