Oman Medical Journal | 2021
Maintenance Intravenous Fluids in Children, Should We Change?
Abstract
Maintenance intravenous fluids (IVFs) are an integral part of daily hospital care for sick children. Children who are awaiting surgery and kept nil per oral or children who cannot or should not take orally for various clinical conditions are kept on IVFs. The type of maintenance IVFs chosen for children was historically based on sodium chloride (NaCl) and fluid requirements of the patients as estimated by Holliday and Segar in 1957.1 Solutions containing NaCl concentrations including 0.18%, 0.2%, 0.3%, 0.45%, and 0.9% have been used for children with different clinical conditions. Solutions containing sodium concentrations close to the human serum sodium concentration of 135–145mmol/L are collectively called isotonic solutions. Isotonic solutions include 0.9% NaCl containing 157 mmol/L and Ringer’s lactate containing 130 mmol/L NaCl.2 Ironically, although being called isotonic solutions, neither 0.9% NaCl nor Ringer’s lactate have sodium content in the range of normal human serum. A sodium concentration of 157 mmol/L in 0.9% solution is actually supraphysiological and also contains supraphysiological amounts of chloride. On the other hand solutions containing less sodium than the above ‘isotonic’ solutions are called as hypotonic solutions and include 0.18%, 0.2%, 0.3%, and 0.45% NaCl solutions. In the early 1990s, concerns were raised about using different kinds of hypotonic IVFs, with few children developing devastating outcomes like hyponatremic encephalopathy and death.3 More reports of hyponatremia emerged during the early years of the millennium about children admitted to the intensive care unit who were not on 0.9% NaCl.4,5 Authors hence advocated for the use of 0.9% NaCl as a safer option in response to iatrogenic hyponatremia in children, particularly the critically ill.6 The American Academy of Pediatrics (AAP) in 2018 reviewed the meta-analyses and randomized controlled trials looking at the use of isotonic versus hypotonic IVFs in children. The AAP recommended using 0.9% NaCl or isotonic solutions as maintenance fluids in children aged one month to 18 years of age.2 Studies that were reviewed in the guidelines included children who were on different hypotonic maintenance fluids, including 0.18% NaCl. The guidelines excluded children with neurosurgical disorders, congenital or acquired, cardiac disease, hepatic disease, cancer, renal dysfunction, diabetes insipidus, voluminous watery diarrhea, severe burns, neonates younger than 28 days old, or in the neonatal intensive care unit.2 The guidelines also directed future research addressing the suitability of a 0.9% NaCl solution for children and the risk of hypernatremia, acidosis, or other complications from such fluids.2 Like many parts of the world, the tertiary hospitals in Oman have recently adopted the AAP guidelines and started using 0.9% NaCl in children for fear of hyponatremia-related brain injury when using hypotonic saline solutions. Previously, the standard practice in Oman was to use 0.45% NaCl as the maintenance solution for children and no other hypotonic solutions. Although many clinicians in Oman report that they have not encountered the side effects reported by other studies of iatrogenic hyponatremia, they are all concerned about the safety of their patients. On the other hand, clinicians are concerned that using supraphysiological concentrations of 0.9% NaCl editorial Oman Medical Journal [2021], Vol. 36, No. 4: e278