title: A prospective trial comparing isotonic with hypotonic maintenance fluids for prevention of hospital-acquired hyponatraemia.
abstract: Recent literature suggests that hypotonic fluids increase the risk of hospital-acquired hyponatraemia; despite this, hypotonic fluids are widely used.
  
  
  
  To compare the change in serum sodium following the use of hypotonic (0.3% saline, 0.45% saline) or isotonic (0.9% saline) intravenous (IV) maintenance solutions in hospitalised children.
  
  
  
  This was a randomised controlled trial. Children aged 3 months to 15 years with medical or surgical disorders were randomised to receive one of three maintenance IV fluids: two hypotonic solutions (3.3% dextrose in 0.3% saline or 5% dextrose in 0.45% saline) and one isotonic solution (5% dextrose in 0.9% saline). The primary outcome was serum sodium levels at 8 hours. Secondary outcomes included the incidence of hospital-acquired hyponatraemia, adverse events attributable to IV solutions and length of hospital stay.
  
  
  
  151 children were assigned randomly to receive 0.3% saline (n = 49), 0.45% saline (n = 50) or 0.9% saline (n = 52). Baseline characteristics were similar for the three groups. At 8 hours, mean (SD) serum sodium was lower in the hypotonic solutions groups [0.3% saline 134.65 (1.9) mmol/L, 0.45% saline 134.90 (2.3) mmol/L than 0.9% saline 137.98 (2.8) mmol/L] (P < 0.0001). The incidence of hospital-acquired hyponatraemia was higher in the hypotonic groups [0.3% saline 10/49 (20.4%), 0.45% saline 11/50 (22%) than 0.9% saline 1/52 (1.9%), P = 0.006). There were no differences in other adverse effects or length of hospital stay between the groups.
  
  
  
  Hypotonic IV solutions increase the incidence of hospital-acquired hyponatraemia. Isotonic solutions are a safer alternative.
authors.affiliation: a Department of Pediatrics, Hospital Regional Materno Infantil de Alta Especialidad, Tecnológico de Monterrey School of Medicine , Nuevo León , México.
authors.forename: Claudia Montserrat
authors.initials: CM
authors.lastname: Flores Robles
authors.affiliation: b Department of Clinical Epidemiology and Biostatistics , McMaster University , Hamilton , Ontario, Canada.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Cuello García
mesh_terms: D061605:Administration, Intravenous; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007010:Hyponatremia / Q000139:chemically induced / Q000517:prevention & control*; D007038:Hypotonic Solutions / Q000008:administration & dosage* / Q000009:adverse effects; D007049:Iatrogenic Disease; D015994:Incidence; D007223:Infant; D007552:Isotonic Solutions / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D011446:Prospective Studies; D012964:Sodium / Q000097:blood*
chemical_list: D007038:Hypotonic Solutions; D007552:Isotonic Solutions; D012964:Sodium
keywords: Hospital-acquired hyponatraemia; Hyponatraemia; Hypotonic solutions; Intravenous fluids; Isotonic solutions