title: Isotonic versus hypotonic maintenance IV fluids in hospitalized children: a meta-analysis.
abstract: OBJECTIVE
  To assess evidence from randomized controlled trials (RCTs) on the safety of isotonic versus hypotonic intravenous (IV) maintenance fluids in hospitalized children.
  
  
  METHODS
  We searched PubMed, Embase, Cochrane Library, and clinicaltrials.gov (up to April 11, 2013) for RCTs that compared isotonic to hypotonic maintenance IV fluid therapy in hospitalized children. Relative risk (RR), weighted mean differences, and 95% confidence intervals (CIs) were calculated based on the effects on plasma sodium (pNa). The risk of developing hyponatremia (pNa <136 mmol/L), severe hyponatremia (pNa <130 mmol/L), and hypernatremia (pNa >145 mmol/L) was evaluated. We adopted a random-effects model in all meta-analyses. Sensitivity analyses by missing data were also performed.
  
  
  RESULTS
  Ten RCTs were included in this review. The meta-analysis showed significantly higher risk of hypotonic IV fluids for developing hyponatremia (RR 2.24, 95% CI 1.52 to 3.31) and severe hyponatremia (RR 5.29, 95% CI 1.74 to 16.06). There was a significantly greater fall in pNa in children who received hypotonic IV fluids (-3.49 mmol/L versus isotonic IV fluids, 95% CI -5.63 to -1.35). No significant difference was found between the 2 interventions in the risk of hypernatremia (RR 0.73, 95% CI 0.22 to 2.48). None of the findings was sensitive to imputation of missing data.
  
  
  CONCLUSIONS
  Isotonic fluids are safer than hypotonic fluids in hospitalized children requiring maintenance IV fluid therapy in terms of pNa.
authors.affiliation: Department of Pediatrics, Second Affiliated Hospital of Medical School of Xi'an Jiaotong University, 157 Xiwu Rd, Xi'an, Shaanxi 710004, China. xiaoyanfeng.xjtu@gmail.com.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.forename: Erdi
authors.initials: E
authors.lastname: Xu
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D002648:Child; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D006760:Hospitalization; D006801:Humans; D006955:Hypernatremia / Q000209:etiology* / Q000517:prevention & control; D007010:Hyponatremia / Q000209:etiology* / Q000517:prevention & control; D007038:Hypotonic Solutions / Q000009:adverse effects*; D007262:Infusions, Intravenous; D007552:Isotonic Solutions / Q000009:adverse effects*; D015233:Models, Statistical; D017063:Outcome Assessment, Health Care; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D012720:Severity of Illness Index
chemical_list: D007038:Hypotonic Solutions; D007552:Isotonic Solutions
keywords: children; hyponatremia; hypotonic fluid; intravenous fluid; isotonic fluid