1. Pediatr Nephrol. 2010 Aug;25(8):1471-5. Epub 2010 Jan 27.

Incidence of hyponatremia in children with gastroenteritis treated with hypotonic
intravenous fluids.

Hanna M, Saberi MS.

Department of Pediatrics, Saint John Hospital and Medical Center, Detroit, MI,
USA. mina-hanna@uiowa.edu

Comment in
    Pediatr Nephrol. 2010 Aug;25(8):1383-4.

Hypotonic saline solutions have been used for over five decades to treat children
with diarrheal dehydration. However, concern has recently been raised about the
potential for iatrogenic hyponatremia as a result of this therapy. We reviewed
the medical records of 531 otherwise healthy children with gastroenteritis who
had been admitted to the hospital for intravenous fluid therapy. We
retrospectively collected data on 141 of these children who had received two
serum electrolytes (one upon admission and the other 4-24 h thereafter). The
remaining 390 children were excluded because their charts lacked the required
data. We analyzed data in 124 of these 141 patients whose initial serum sodium
(Na) level was between 130-150 mEq/l and excluded 17 patients whose admission
serum sodium fell outside this range. All patients were treated with intravenous 
hypotonic fluids (5% dextrose in 0.2% saline, n = 4; 5% dextrose in 0.3% saline, 
n = 102; 5% dextrose in 0.45% saline, n = 18 patients) as maintenance fluid
therapy or maintenance fluid plus deficit therapy; 100 of these children had
received an initial saline bolus of 21.05 +/- 8.5 ml/kg upon admission. The serum
Na level decreased by 1.7 +/- 4.3 mEq/l in the whole group. Of the 97 children
with isonatremia (Na 139.5 +/- 2.7 mEq/l) on admission, 18 (18.5%) developed mild
hyponatremia (Na 133.4 +/- 0.9 mEq/l, range 131-134), with a decrease in serum Na
of 5.7 +/- 3.1 mEq/l, and 79 remained isonatremic (Na 138.3 +/- 2.7 mEq/l), with 
a decrease in serum Na of 1.8 +/- 3.4 mEq/l (p < 0.0005). There was no
significant difference in type, rate, or amount of intravenous fluid or saline
bolus (26.1 +/- 10.4 vs. 20.2 +/- 8.6 ml/kg, respectively) administered in these 
two groups. Children who became hyponatremic were older (5.8 +/- 2.7 years) than 
those who remained isonatremic (2.8 +/- 3.1 years) (p < 0.0005), but there was no
statistical difference in gender, degree of dehydration, and severity of
metabolic acidosis between the two groups. Although serum Na increased by 3.9 +/-
2.5 mEq/l in 19 patients with mild hyponatremia upon admission (Na 132.8 +/- 1.3 
to 136.7 +/- 2.6 mEq/l) and 73% of these became isonatremic, hypotonic saline
solutions have the potential to cause hyponatremia in children with
gastroenteritis and isonatremic dehydration.

PMID: 20108002  [PubMed - indexed for MEDLINE]