Perioperative water and electrolyte balance and water homeostasis regulation in children with acute surgery.

Background: Hospital-acquired hyponatremia remains a feared event in patients receiving hypotonic fluid therapy. Our objectives were to assess post-operative plasma-sodium concentration and to provide a physiological explanation for plasma-sodium levels over time in children with acute appendicitis.

Methods: Thirteen normonatremic (plasma-sodium ≥135 mmol/L) children (8 males), median age 12.