title: Bolus fluid therapy and sodium homeostasis in paediatric gastroenteritis.
abstract: OBJECTIVE
  The study aims to assess the risk of developing hyponatraemia when large-volume bolus fluid rehydration therapy is administered.
  
  
  METHODS
  We conducted a prospective randomised study in a tertiary-care centre emergency department. Participants included children with gastroenteritis and dehydration requiring intravenous rehydration. They were randomised to receive 60 mL/kg (large) or 20 mL/kg (standard) 0.9% saline bolus followed by maintenance 0.9% saline for 3 h. Biochemical tests were performed at baseline and 4 h. The primary outcome measure was the development of hyponatraemia at 4 h. Secondary outcome measures were (i) change in sodium relative to baseline value; (ii) magnitude of decrease among those who experienced a decrease; (iii) risk of hypernatraemia; (iv) correlations between urine parameters and hyponatraemia; and (v) fluid overload.
  
  
  RESULTS
  Eighty-four of 224 (38%) participants were hyponatraemic at baseline. At 4 h, 22% (48/217) had a dysnatraemia, and similar numbers of children were hyponatraemic in both groups: large (23% (26/112)) versus standard (21% (22/105)) (P = 0.69). Among initially hyponatraemic children, 63% (30/48) who received large-volume rehydration and 44% (15/34) of those administered standard rehydration were isonatraemic at 4 h (P = 0.10). Overall, children who received 60 mL/kg experienced a larger mean increase (1.6 ± 2.4 mEq/L vs. 0.9 ± 2.2 mEq/L; P = 0.04) and were less likely to experience a sodium decrease of ≥2 mEq/L (8/112 vs. 17/105; P = 0.04) than those administered 20 mL/kg.
  
  
  CONCLUSIONS
  Large-volume bolus rehydration therapy with 0.9% saline is safe. It does not promote the development of hyponatraemia over the short term, but hastens the resolution of baseline hyponatraemia.
authors: Sections of Emergency Medicine and Gastroenterology, Department of Paediatrics, Alberta Children's Hospital, Alberta, Canada. stephen.freedman@albertahealthservices.ca
authors: Stephen B
authors: SB
authors: Freedman
authors: Denis F
authors: DF
authors: Geary
mesh_terms: D002170:Canada; D002648:Child; D003681:Dehydration / Q000150:complications / Q000628:therapy*; D005260:Female; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D005759:Gastroenteritis / Q000150:complications / Q000628:therapy*; D006706:Homeostasis; D006801:Humans; D007010:Hyponatremia / Q000628:therapy*; D007262:Infusions, Intravenous; D008297:Male; D011446:Prospective Studies; D015532:Rehydration Solutions / Q000008:administration & dosage*; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D015532:Rehydration Solutions; D012965:Sodium Chloride; D012964:Sodium