Neville et al reported on a randomised controlled trial of hypotonic versus isotonic saline for rehydration of children with gastroenteritis. They found that isotonic saline was superior with regards to correction of hyponatraemia.¹ The majority of patients in the study received a “rapid replacement protocol” which entailed the infusion of 40 ml/kg of isotonic saline over 4 hours in the isotonic saline arm of the study. The authors did not report on important known adverse effects associated with rapid infusion of isotonic …