Background: The principles for maintenance intravenous fluid prescription in children were developed in the 1950s. These guidelines based on the use of hypotonic solutions have been challenged regularly for they seem to be associated with an increased risk of hospital-acquired hyponatremia.
Case presentation: We report the case of a 4-week-old Caucasian child admitted for acute bronchiolitis who received hypotonic maintenance fluids and developed severe hyponatremia (94 mmol/L) with hyponatremic encephalopathy.
Conclusion: This clinical situation can serve as a reminder of the latest recommendations from the American Academy of Pediatrics regarding the use of intravenous fluids that promote the use of isotonic fluids in children.
Keywords: Hyponatremia; Hypotonic fluid; Intensive care; Isotonic fluid.