Friedman et al, conducted a randomized controlled trial involving 110 patients aged 1 month to 18 years of age. Patients were randomized into 0.9% saline (isotonic) group and 0.45% saline (hypotonic) group.The primary outcome was to measure mean sodium level at 48 hours.The secondary outcomes were mean sodium level at 24 hours, hyponatremia, hypernatremia, weight gain, edema and hypertension. The mean Na levels in isotonic and hypotonic group were similar. Two of the 56 patients developed hyponatremia in hypotonic group (serum sodium levels of 134meq/l after 24 hours). Mean serum sodium levels at 24 hours did not differ between the groups (140.5 [2.7] vs 139.6 [2.7] meq/l respectively, [95% CI:-0.22 to 2.02 meq/l]; p=0.14. One patient in each group developed hypernatremia with serum sodium levels of 147meq/l at 24 hours. Two patients in each group developed hypertension and 2 patients in the isotonic group developed edema.