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% NaCl in 5% dextrose) or Isotonic fluid (60% Standard maintenance volume as 0.9% NaCl solution in 5% dextrose). OUTCOME MEASURES Primary: Incidence of hyponatremia. Secondary: Serum sodium, serum osmolality, 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%CI: -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% CI: 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.