A randomized controlled trial of isotonic versus hypotonic maintenance intravenous fluids in hospitalized children

Diane Laforte,James Fairbairn,Bethany J Foster,Fiona Houghton,Thomas G Saba

doi:10.1186/1471-2431-11-82

Diane Laforte, James Fairbairn + Show 3 more

Open Access

https://doi.org/10.1186/1471-2431-11-82

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Journal: BMC Pediatrics	Publication Date: Sep 23, 2011
Citations: 76	License type: cc-by

Affiliation: Montreal Children's Hospital, McGill University

Abstract

BackgroundIsotonic saline has been proposed as a safer alternative to traditional hypotonic solutions for intravenous (IV) maintenance fluids to prevent hyponatremia. However, the optimal tonicity of maintenance intravenous fluids in hospitalized children has not been determined. The objective of this study was to estimate and compare the rates of change in serum sodium ([Na]) for patients administered either hypotonic or isotonic IV fluids for maintenance needs.MethodsThis was a masked controlled trial. Randomization was stratified by admission type: medical patients and post-operative surgical patients, aged 3 months to 18 years, who required IV fluids for at least 8 hours. Patients were randomized to receive either 0.45% or 0.9% saline in 5.0% dextrose. Treating physicians used the study fluid for maintenance; infusion rate and the use of additional fluids were left to their discretion.ResultsSixteen children were randomized to 0.9% saline and 21 to 0.45% saline. Baseline characteristics, duration (average of 12 hours) and rate of study fluid infusion, and the volume of additional isotonic fluids given were similar for the two groups. [Na] increased significantly in the 0.9% group (+0.20 mmol/L/h [IQR +0.03, +0.4]; P = 0.02) and increased, but not significantly, in the 0.45% group (+0.08 mmol/L/h [IQR -0.15, +0.16]; P = 0.07). The rate of change and absolute change in serum [Na] did not differ significantly between groups.ConclusionsWhen administered at the appropriate maintenance rate and accompanied by adequate volume expansion with isotonic fluids, 0.45% saline did not result in a drop in serum sodium during the first 12 hours of fluid therapy in children without severe baseline hyponatremia. Confirmation in a larger study is strongly recommended.Clinical Trial Registration NumberNCT00457873 (http://www.clinicaltrials.gov/)

Highlights

Isotonic saline has been proposed as a safer alternative to traditional hypotonic solutions for intravenous (IV) maintenance fluids to prevent hyponatremia
Several authors have argued that administration of hypotonic fluids to hospitalized children - many of whom have a non-osmotic stimulus for anti-diuretic hormone (ADH) secretion - may lead to clinically important hyponatremia [10,11,12,13]
Iatrogenic hyponatremia has been the reported cause of neurological injury or death in more than 50 cases [13,14,15,16,17,18]. In many of these cases, fluids were administered at rates well above those typically recommended for maintenance [19]- a practice that has since been identified as a risk factor for hyponatremia [10]

Summary

Introduction

Isotonic saline has been proposed as a safer alternative to traditional hypotonic solutions for intravenous (IV) maintenance fluids to prevent hyponatremia. For almost half a century, pediatricians have ordered “maintenance” intravenous (IV) fluids for children according to the guidelines set out by Holliday and Segar: 100 cc/kg/day for the first 10 kg, plus 50 cc/kg/day for the 10 kg, plus 20 cc/kg/day for each remaining kilogram [1]. Based on these recommendations for water intake, and on the estimated daily sodium and potassium needs of 3 milliequivalents and 2 milliequivalents per 100 kcal per day respectively, a hypotonic solution (0.2% saline) was recommended. The likelihood and severity of complications depend on both the rate of fall in serum sodium concentration [Na] and the absolute [Na] [20]

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