The events of hyponatremia occurred in the first 24 h after surgery in the majority of affected participants and plasma-AVP levels were elevated in both treatment arms on post-operative day 1.48 Similarly, in another controlled trial,49 the administration of 0.45% saline as compared with 0.9% saline solution in children after abdominal surgery was a risk factor for hyponatremia. The gene discussed is AVP; the disease is Hyponatremia.