Acute hyponatremia in the perioperative period: insights into its pathophysiology and recommendations for management

Our purpose is to review the topic of acute postoperative hyponatremia by f ocusing on pertinent aspects of the physiology of water and solute excretio n. Four areas will be highlighted: an examination of the source of addition of electrolyte-free water, an exploration of the basis fur the very large natriuresis that occurs during cerebral salt wasting following neurosurgery , possible reasons to explain why acute postoperative hyponatremia may pose a greater risk for young women [Ayus and Arieff 1996, Ayus et al. 1992, Ar ieff 1986, Wijdick ct al. 1991], and issues related to treatment of acute h yponatremia.