Incidence of postoperative hyponatremia and complications in critically-III children treated with hypotonic and normotonic solutions

Objective To determine the incidence and clinical consequences of postoperative hyponatremia in children. Study design We performed a retrospective analysis of postoperative admissions to the pediatric intensive care unit (excluding cardiac, neurosurgical, and renal). The incidence of severe (serum sodium < 125 mmol/L or symptoms) and moderate (serum sodium < 130 mmol/L) hyponatremia in children receiving bypotonic (HT) and normotonic (NT) fluids was calculated. Results Out of a total of 145 children (568 sodium measurements; 116 HT and 29 NT), we identified 16 with hyponatremia (11%). The incidences of moderate (10.3% vs 3.4%, P =.258) and severe (2.6% vs 0%; P =.881) hyponatremia were not significantly different in the HT and NT groups. There were no neurologic sequelae or deaths related to hyponatremia. Conclusions in our study group, hyponatremia was common, but morbidity and death were not observed. Careful monitoring of serum sodium level may be responsible for this lack of adverse outcomes. Larger, prospective studies are needed to determine whether the incidence of hyponatremia differs between the HT and NT groups.