Hyponatremia More Common With Hypotonic Fluids in Hospitalized Kids

September 17, 2013

NEW YORK (Reuters Health) Sep 17 - A new study provides more evidence that hypotonic fluids are associated with development of hyponatremia in hospitalized children.

Still, the researchers say it's unclear whether isotonic maintenance fluids would fully address the problem of iatrogenic hyponatremia, given that in their study more than 25% of children give isotonic fluids still became hyponatremic.

"It is quite possible that a one-size-fits-all approach to IV maintenance fluid management is no longer tenable," they conclude in a paper online now in The Journal of Pediatrics. They say studies are needed to identify factors that can be used to guide fluid management in hospitalized children.

Dr. Francis Carandang and colleagues from Stanford University School of Medicine and Lucile Packard Children's Hospital reviewed data on 1,048 children hospitalized across the entire spectrum of pediatric disease who had normal values of serum sodium upon admission. This allowed them to analyze the association between hypotonic maintenance fluids and hyponatremia on a larger and more generalizable scale than what has been done before, they say.

About two-thirds of the children (674, or 64.3%) received hypotonic fluids and 374 (35.5%) received isotonic fluids upon admission. Hyponatremia develop in 364 (34.7%), including 260 (38.6%) who received hypotonic fluids and 104 (27.8%) who received isotonic fluids, yielding an unadjusted odds ratio of 1.63 (p<0.001).

After adjusting for intergroup differences and potential confounding factors, children who received hypotonic fluids remained more likely to develop hyponatremia (adjusted OR 1.37). Time-to-event analysis showed that hyponatremia developed earlier in patients receiving hypotonic fluids than in those receiving isotonic fluids.

In multivariable analysis, clinical factors associated with the development of hyponatremia included surgical admission (aOR 1.44), cardiac admitting diagnosis (aOR 2.08) and hematology/oncology admitting diagnosis (aOR 2.37).

In this study, hyponatremia was common regardless of maintenance fluid tonicity, the researchers point out. One of the most "striking" findings, they say, is the relatively high rate of hyponatremia even in those receiving isotonic fluids (roughly 28%). Still, the administration of hypotonic maintenance fluids was associated with a higher risk of nosocomial hyponatremia.

"Additional clinical characteristics modified the hyponatremic effect of hypotonic fluid, and it is possible that optimal maintenance fluid therapy now requires a more individualized approach," they say.

"Rather than focusing solely on fluid composition, future studies designed to determine optimal fluid strategies in hospitalized children should aim to identify additional clinical hyponatremic risk factors, examine alternative approaches to deliver less electrolyte-free water (EFW) such as reduced maintenance fluid volumes in the setting of nonosmotic stimuli for antidiuretic hormone (ADH) production, and assess the ramifications of greater use of isotonic fluids," they conclude.

The authors could not be reached for comment by press time.

SOURCE: http://bit.ly/1eLAuZc

J Pediatr 2013.


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