AVP and Hyponatremia: Factors such as surgical stress, anaesthesia, and inadequate management of postoperative pain and nausea [8,9,10] can contribute to the development of Syndrome of Inappropriate Antidiuretic Hormone (SIADH), a condition in which the release of antidiuretic hormone is stimulated despite no osmotic trigger, resulting in water retention and dilutional hyponatraemia [9].