Objective To evaluate the risk of hyponatremia following administration of hypotonic (HT) or isotonic (IT) fluids in postoperative paediatric patients.
Methods Randomised controlled trial phase IV. Surgical paediatric patients who required IV fluids for at least 6 h, aged 6 months to 15 years, >6 kg weight, serum sodium 130–150 mEq/L at admission were included. Patients were randomised to receive 5% dextrose 0,3% saline solutión (HT) or 5% dextrose 0,9% saline solution (IT). We analysed plasma levels of sodium, calcium and potassium on admission, 8, 24, 48 h and PICU discharge. Statistics analysis p < 0.05.?
Results 137 patients were included, 66 HT and 71 IT. Baseline characterics were similar in both groups. The highest frequency of hyponatremia occurs at 8 h (20.5%) and 24 h (27.3%) of income. Patients receiving HT fluid have at greater risk of developing hyponatremia than those receiving IT fluid at 8, 24 h and at discharge. Sodium leves are shown in table. The risk is 12,5 (OR 12,5 95% 3,49- 45.1) times higher at 8 h and 5,4 (1,28–23,37) times higher at 24 h. Severe hyponatremia (<125 mEq/l) ocurred in only 1 patient, and 6 moderate (130–125 mEq/l) hyponatremia. There was no significant risk of hypernatremia in the IT group. Ionic calcium concentration 1.15–1.3 mmol/l, potassium 3.6–4.4 mEq/l.
Conclusions Postoperative paediatric patient have more risk of hyponatremia if they receive an HT fluid. Calcium and potassium supplements are not needed at least in the first 24 h.