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 focusing on pertinent aspects of the physiology of water and solute excretion. Four areas will be highlighted: an examination of the source of addition of electrolyte-free water, an exploration of the basis for 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, Arieff 1986, Wijdick et al. 1991], and issues related to treatment of acute hyponatremia.