Table 1

 Characteristics of included studies

Brazel (1996)14Dagli (1997)16Neville (2006)15Hoorn (2004)18Burrows (1983)17Wilkinson (1992)19
CVS, cardiovascular; LR, Lactated Ringers; NS, normal saline; PNa, plasma sodium; pre/post-op, pre- or postoperative; Gp, group; NaCl, sodium chloride; RCT, randomised controlled trial.
Age (years)12.3–18.11–126 months–14 years7±66–162 months–14 years
Inclusion criteriaAdolescent females undergoing idiopathic scoliosis repairASA 1 patients undergoing elective minor surgeryGastroenteritis with dehydration37 patients with hospital acquired hyponatraemia, 111 isonatraemic historical controlsPreviously healthy patients with idiopathic scoliosis undergoing surgical correctionCraniofacial surgery
MethodologyRCT, unmaskedControlled trialRCT, unmaskedCase controlCohort studyRetrospective chart review
Intervention (all solutions included appropriate dextrose content unless otherwise stated)Near isotonic solution (LR), n = 5; v hypotonic solutions: (0.3%–0.18% NaCl), n = 7Gp 1: LR Gp 2: 1% Dextrose in LR Gp 3: 3.3% Dextrose in 0.3% NaClGp1: 0.45% NaCl Gp 2: 0.9% NaClStandard prescription for maintenance IV fluidsPostoperative maintenance fluids: Isotonic (LR), n = 4 Hypotonic (0.25–0.5% NaCl), n = 20Isotonic (LR or NS), n = 30 Hypotonic (0.16–0.5% NaCl), n = 26
PNa mmol/lGreater and more sustained drop in PNa in hypotonic group (p<0.01)Post-op PNa in Gp 3 significantly lower (p<0.05). No significant change in Gp 1 and 2Mean PNa after 4 hours: Gp 1 134.3 mmol/l (2.1) Gp 2 136.3 mmol/l (3.3)Cases: PNa dropped from 139±3 to 133±2 mmol/l in 19±10 hours Controls: PNa 140±2 mmol/lGreater fall in PNa in hypotonic group: 6.2±2.9 mEq/l (p⩽0.05); 3.0±0.8 mEq/l in isotonic groupMedian PNa: 130.5 (121–136) in hypotonic Gp; 139 in isotonic group
Hyponatraemia (PNa <136)1 patient in LR group, 7 in hypotonic groupPNa in hypotonic group (Gp 3): 133.3±4.6 mEq/l (p<0.05)21/31 in Gp 1, 2/21 in Gp 2All cases by definitionPost-op PNa: 131±2.8 in hypotonic group; 135±1.9 mmol/l in isotonic group20/26 patients in hypotonic group, 2/30 in isotonic group
Severe hyponatraemia (PNa <130)4 in hypotonic groupNot described5/22 in Gp 1 (PNa ⩽130); 0/22 in Gp 2Not described5 patients in hypotonic group11 in hypotonic group
Clinical sequelae related to hyponatraemiaNot mentionedNot describedNone describedMore nausea and vomiting reported in hyponatraemic groupIncreased interstitial pulmonary fluid in hypotonic group (p<0.05)Seizures: 2/26 in hypotonic group
Hypernatraemia (PNa >145)NoneNoneNoneNoneNoneNone