Randomised controlled trial of intravenous maintenance fluids.
OBJECTIVE
Traditional paediatric intravenous maintenance fluids are prescribed using hypotonic fluids and the weight-based 4:2:1 formula for administration rate. However, this may cause hyponatraemia in sick and post-operative children. We studied the effect of two types of intravenous maintenance fluid and two administration rates on plasma sodium concentration in intensive care patients.


METHODS
A Factorial-design, double-blind, randomised controlled trial was used. We randomised 50 children with normal electrolytes without hypoglycaemia who needed intravenous maintenance fluids for >12 h to 0.9% saline (normal saline) or 4% dextrose and 0.18% saline (dextrose saline), at either the traditional maintenance fluid rate or 2/3 of that rate. The main outcome measure was change in plasma sodium from admission to 12-24 h later.


RESULTS
Fifty patients (37 surgical) were enrolled. Plasma sodium fell in all groups: mean fall 2.3 (standard deviation 4.0) mmol/L. Fluid type (P = 0.0063) but not rate (P = 0.12) was significantly associated with fall in plasma sodium. Dextrose saline produced a greater fall in plasma sodium than normal saline: difference 3.0, 95% confidence interval 0.8-5.1 mmol/L. Full maintenance rate produced a greater fall in plasma sodium than restricted rate, but the difference was small and non-significant: 1.6 (-0.7, 3.9) mmol/L. Fluid type, but not rate, remained significant after adjustment for surgical status. One patient, receiving normal saline at restricted rate, developed asymptomatic hypoglycaemia.


CONCLUSIONS
Sick and post-operative children given dextrose saline at traditional maintenance rates are at risk of hyponatraemia.
Yung
Michael
M
Paediatric Intensive Care Unit, Women's and Children's Hospital, South Australia, Australia. michael.yung@cywhs.sa.gov.au
Keeley
Steve
S
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D005947:Glucose / Q000008:administration & dosage*; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D007038:Hypotonic Solutions / Q000008:administration & dosage; D007223:Infant; D007262:Infusions, Intravenous / Q000379:methods; D015278:Intensive Care Units, Pediatric; D007552:Isotonic Solutions / Q000008:administration & dosage; D011182:Postoperative Care / Q000379:methods; D012964:Sodium / Q000097:blood; D012965:Sodium Chloride / Q000008:administration & dosage*; D016896:Treatment Outcome
D007038:Hypotonic Solutions; D007552:Isotonic Solutions; D012965:Sodium Chloride; D012964:Sodium; D005947:Glucose