• brain damage
• elective surgery
• fluid management
• hyponatraemia

At least two children in Northern Ireland have died in recent years as a result of severe hyponatraemia (serum sodium <130 mmol/l).¹ Death or neurological morbidity related to this condition has been reported in more than 50 children.² Although risk factors include vomiting, pain, anxiety, disturbances of the central nervous system, and metabolic and endocrine disorders, it has become recognised that any child receiving intravenous fluids or oral rehydration is potentially at risk.³ The particular risks associated with the postoperative period were highlighted by Arieff in 1998, who pointed out that plasma levels of vasopressin (antidiuretic hormone, ADH) are raised in virtually every child in the postoperative period.⁴ If …