Intravenous isotonic fluids induced a positive trend in natraemia in children admitted to a general paediatric ward.

Aim: Using hypotonic intravenous solutions for baseline fluid needs in paediatric patients on a nil by mouth diet may cause serious complications, including hyponatraemia, cerebral oedema and even death. We analysed the evolution of natraemia and explored any adverse effects on children treated with intravenous isotonic fluids.

Methods: This was a prospective study of 50 patients consecutively admitted to a general paediatric ward who were treated with isotonic intravenous fluids and on a nil by mouth diet.

Results: The most prevalent diagnosis was acute gastroenteritis (64%). Hyponatraemia, defined as sodium in plasma of <135 mEq/L, affected 22% of the subjects, but none displayed this during the first postadmission analysis at a median of eight hours. Sodium levels changed by an average of +0.64 mEq/L/hour. The subgroup analysis (0.91 versus 0.56 mEq/L/hour, p = 0.02) and multiple linear regression (R(2) = 0.756) showed a greater increase in sodium when patients had hyponatraemia on admission. Iatrogenic hyponatraemia was not detected, but two patients showed mild hypernatraemia and 35% developed clinically insignificant hyperchloraemia.

Conclusion: Using intravenous isotonic fluids induced a positive trend in natraemia on a general paediatric ward, particularly if patients were hyponatraemic when admitted, and did not induce clinically relevant adverse effects.