Can isotonic fluid therapy lead to electrolyte disorders in acutely ill kids?

When treating acutely ill children, are all fluid therapies created equal? An investigation in JAMA Pediatrics examines whether commercially available plasmalike isotonic fluids lead to a risk of electrolyte disorders in this population.¹

The researchers ran an unblinded, randomized clinical pragmatic trial that was performed at a pediatric emergency department in Finland. The patients included in the study were aged 6 months to 12 years, were hospitalized because of an acute illness, and required intravenous fluid therapy. Exclusion criteria included a need for renal replacement therapy; severe liver disease; pediatric cancer requiring protocol-determined chemotherapy hydration; inborn errors of metabolism; a plasma sodium concentration of less than 130 mmol/L or greater than 150 mmol/L on admission; a plasma potassium concentration of less than 3.0 mmol/L on admission; clinical need of fluid therapy with 10% glucose solution; or a history of diabetes, diabetic ketoacidosis, or diabetes insipidus. Each patient was randomly assigned to receive either commercially available plasmalike isotonic fluid therapy (140 mmol/L of sodium and 5 mmol/L potassium in 5% dextrose) or moderately hypotonic fluid therapy (80 mmol/L sodium and 20 mmol/L potassium in 5% dextrose).

A total of 614 children were included in the study’s cohort, with an average age of 4.0 years. Investigators found that a clinically significant electrolyte disorder was more common in the children who received the plasmalike isotonic fluid therapy (61 of 308 patients) than in the children who received moderately hypotonic fluid therapy (9 of 305 patients; 95% CI of the difference, 12%-22%; P < .001). Overall the risk of developing an electrolyte disorder was 6.7-fold greater in children who were given isotonic fluid therapy. Among the patients who received the plasmalike isotonic fluid therapy and developed an electrolyte disorder, hypokalemia developed in 57 patients and hypernatremia developed in 4 patients. Additionally, weight change was greater in patients who received the isotonic, plasmalike fluid therapy in comparison with the children who received mildly hypotonic fluids (mean weight gain, 279 vs 195 g; 95% CI, 16-154 g; P = .02).

Investigators concluded that using commercially available plasmalike isotonic fluid therapy led to a marked increase in the risk of a clinically significant electrolyte disorder in acutely ill children. The same was not true when using moderately hypotonic fluid therapy containing 20 mmol/L of potassium, which had been the widely used fluid therapy previously.

Reference

1. Lehtiranta S, Honkila M, Kallio M, et al. Risk of electrolyte disorders in acutely ill children receiving commercially available plasmalike isotonic fluids. JAMA Pediatr. October 26, 2020. doi:10.1001/jamapediatrics.2020.3383