Safety and Efficacy of Isotonic (0.9%) vs. Hypotonic (0.18%) Saline as Maintenance Intravenous Fluids in Children: A Randomized Controlled Trial

Objective: To compare the safety and efficacy of isotonic versus hypotonic maintenance fluid in children. Design: Randomized controlled trial. Setting: Tertiary-level teaching hospital. Participants: 60 children (age 0.5 to 12 years) who were admitted and anticipated to receive intravenous fluid for the next 48 hours. Intervention: Hypotonic fluid (Standard maintenance volume as 0.18% NaCI in 5% dextrose) or Isotonic fluid (60% Standard maintenance volume as 0.9% NaCI solution in 5% dextrose). Outcome measures: Primary: Incidence of hyponatremia. Secondary: Serum sodium, serum osniolality, blood sugar, blood urea, serum creatinine, serum potassium, serum chloride, pH, urine output, change in weight, morbidity and death. Results: At 24 hours, hyponatremia was noted in 7 (24%) patients in the isotonic and 16 (55%) in hypotonic group (P=0,031). At 48 hours, hyponatremia was noted in 4 (14%) and 13 (45%) patients in isotonic and hypotonic group, respectively (P=0.02). There was significant change in sodium levels in both isotonic (P=0.036) and hypotonic (P<0.001) intervention groups. The peak fall in mean serum sodium level was noted at 24 hours (-6.5, 95%Cl: -3.5, -9.6 mEq/L; P<0.001) in hypotonic group. In isotonic group, there was significant increase between 24 and 48 hours (4.3, 95% Cl: 0.1, 8.4 mEq/L; P=0.04). Conclusions: Reduced volume isotonic fluid results in fewer episodes of hyponatremia than hypotonic fluid in sick children during the first 48 hours of intravenous fluid therapy.