Background: The infusion of hypotonic solutions in the perioperative period can lead to the development of hyponatraemic encephalopathy which is a severe, life threatening but preventable complication.
Clinical presentation: Seven children aged 3-6 yr, ASA 1 or 2, operated on for a scheduled surgical procedure, presented at the 11th postoperative hour with seizures or status epilepticus, associated with vomiting (5/7), and a constant loss of consciousness (median Glasgow Coma Scale at 7), while one child presented with a respiratory arrest. At arrival in ICU, serum sodium was 120 mmol.L-1. All children had received in the perioperative period an hypotonic solution infusion (mainly dextrose 5%), at a high rate for most of them. Management included mechanical ventilation (3/7), antiepileptic drugs (7/7), fluid restriction (7/7), sodium chloride infusion (5/7), and diuretics (6/7). Serum sodium increased to a mean of 135 mmol.L-1 in 12 hours. Six children had a good neurologic outcome while one child died from brain death.
Conclusion: The use of hypotonic solute in the perioperative period can lead to hyponatremic encephalopathy, a severe neurologic complication of acute hyponatremia. It must be prevented by the use of appropriate solutions i-e isotonic fluids in regards of the low free water elimination capacities of the surgical patient.