Written by Clay Smith
Hypotonic maintenance IV fluid (MIVF) dropped serum sodium at 24 hours compared with isotonic MIVF in pediatric patients. We should stop using D51/2NS for routine MIVF in children.
Why does this matter?
The AAP already recommends isotonic fluid for children 28 days to 18 years who need MIVF, but old habits die hard. If you are in doubt that hypotonic MIVF causes worsening hyponatremia, would a RCT change your mind? Let’s see.
Don’t be diluted, D51/2NS drops Na+
This was an unblinded RCT with 200 pediatric inpatients admitted on MIVF, age 3 months to 12 years, who were randomized to D51/2NS or D5NS. Serum sodium at 24 hours was 136.07 (all in meq/L) in the D51/2NS group and dropped to 134.62 at 24 hours, which was statistically significant. In the D5NS group, sodium was 136.67 and went up slightly to 136.78 at 24 hours, essentially unchanged. By chance, there was an imbalance in the groups, with 32% having mild hyponatremia (Na 130-134) in the D51/2NS group at baseline. For those starting with mild hyponatremia, even more patients became hyponatremic at 24 hours in the D51/2NS group (32% at baseline up to 47% at 24 hours). In the D5NS group, 20% had mild hyponatremia at baseline, and 17% had Na 130-134 at 24 hours. Since the AAP guideline already recommends isotonic MIVF, this study confirms what should already be our practice: use D5NS not D51/2NS.
0.45% Versus 0.9% Saline in 5% Dextrose as Maintenance Fluids in Children Admitted With Acute Illness: A Randomized Control Trial. Pediatr Emerg Care. 2022 Sep 1;38(9):436-441. doi: 10.1097/PEC.0000000000002621. Epub 2022 Jan 26.