Lehtiranta S, Honkila M, Kallio M, et al. - In this unblinded, randomized clinical pragmatic trial involving 614 acutely ill children (mean [SD] age, 4.0 [3.1] years; 315 children were boys [51%] and all 614 were Finnish speaking [100%]), researchers sought to assess the risk for electrolyte disorders, including hyponatremia, hypernatremia, and hypokalemia, and the risk of fluid retention in acutely ill children receiving commercially available plasmalike isotonic fluid therapy. This trial was carried out at the pediatric emergency department of Oulu University Hospital, Finland, from October 3, 2016, through April 15, 2019. Children with acute illness were randomized to receive commercially available plasmalike isotonic fluid therapy (140 mmol/L of sodium and 5 mmol/L potassium in 5% dextrose) or moderately hypotonic fluid therapy (80 mmol/L sodium and 20 mmol/L potassium in 5% dextrose). The authors discovered that commercially available plasmalike isotonic fluid therapy substantially increased the incidence of clinically significant electrolyte disorders, primarily due to hypokalemia, in acutely ill children relative to moderately hypotonic fluid therapy containing 20 mmol/L potassium that was previously commonly used.