Hypotonic and isotonic intravenous maintenance fluids in hospitalised paediatric patients: a randomised controlled trial

Abstract

ObjectiveTo compare the changes in serum sodium and acid/base status in patients receiving hypotonic and isotonic solutions.DesignA randomised, controlled and double-blind clinical trial.SettingDepartment of Paediatrics in a tertiary general hospital (Hospital Universitario Austral) in Buenos Aires, Argentina.PatientsChildren between 29 days and 15 years of age who were hospitalised in the paediatric intensive care unit and general hospital between 12 January 2010 and 30 November 2016, and who required exclusively parenteral maintenance solutions for at least 24 hours.InterventionsA hypotonic solution with 77 mEq/L sodium chloride (0.45% in 5% dextrose) and isotonic solution with 150 mEq/L (0.9% in 5% dextrose) were infused for 48 hours and were labelled.Main outcome measureThe main outcome was to evaluate the incidence of hyponatraemia between patients treated with parenteral hydration with hypotonic or isotonic fluids. The secondary outcome was to estimate the incidence of metabolic acidosis induced by each of the solutions.ResultsThe 299 patients in the present study were randomised to groups that received the hypotonic solution (n=154) or isotonic solution (n=145). The mean serum sodium concentration measurements at 12 hours were 136.3±3.9 mEq/L and 140.1±2.3 mEq/L in the hypotonic and isotonic groups, respectively, with a hyponatraemia incidence of 8.27% (n=12) and 18.8% (n=29) (p<0.001). At 24 hours, 12.4% (n=18) of the isotonic group had developed hyponatraemia compared with 46.1% (n=71) of the hypotonic group (p<0.001). The mean serum sodium concentration measurements were 134.4±5.6 and 139.3±3.1, respectively. No patient developed hypernatraemia (serum sodium concentrations >150 mEq/L) or other adverse outcomes. The relative risk in the hypotonic group was 3.7 (95% CI 2.3 to 5.9), almost four times the risk of developing hyponatraemia than those who received isotonic fluids. There were also no significant differences between the groups with regard to the development of metabolic acidosis. Hypotonic solution, age <12 months and postoperative abdominal surgery were risk factors associated with hyponatraemia.ConclusionsThe incidence of iatrogenic hyponatraemia was greater with the administration of hypotonic fluids compared with that of isotonic fluids. There were no significant differences in the incidence of metabolic acidosis between the groups.

Severe hospital-acquired hyponatremia in acutely ill children receiving moderately hypotonic fluids

“…Several well-conducted randomized controlled trials have shown that isotonic fluids are effective in preventing the development of mild or moderate hyponatremia in acutely ill children receiving maintenance fluid therapy [1][2][3][4]. Accordingly, the American Academy of Pediatrics (AAP) has recommended the use of isotonic maintenance fluid therapy to prevent hyponatremia in children [1].…”

Efficacy and Safety of Isotonic and Hypotonic Intravenous Maintenance Fluids in Hospitalised Children: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

“…One study specifically looking into this outcome was included in our analysis. In a study conducted by Torres et al [ 61 ], there were no significant differences in the incidence of metabolic acidosis between the two treatment arms ( Figure 4 and Figure S5 ). Other studies have found that isotonic fluid causes metabolic acidosis, but many of them involved rapid fluid infusion [ 80 , 81 , 82 , 83 , 84 , 85 ].…”

Association Between Hyponatremia and Maintenance Intravenous Solutions in Critically Ill Children: A Retrospective Observational Study

“…The causes could be related to the administration of anesthetic agents or opioids and the non-osmotic secretion of ADH (22)(23)(24). In patients recovering from abdominal surgery, excessive interstitial fluid immediately after the procedure as well as the presence of colostomies (with possible sodium loss) could also explain this association (16).…”

“…These diuretics can cause volume depletion, or the patient may receive a high supply of fluids which is poorly tolerated by the children because loop diuretics may partially alter the ability to dilute the urine. These effects may be more frequent in very small children, who also have difficulties in maintaining a hypertonic renal medulla ( 16 , 27 ).…”

“…Patients in pediatric critical care have a higher risk of hyponatremia associated with their critical clinical condition and associated comorbidities. An up to four times greater risk of hyponatremia has been reported in the PICU, but it is unclear if this risk changes with the use of the various isotonic solutions available today (balanced or unbalanced) vs. hypotonic solutions ( 15 , 16 ). In this study, we sought to describe the frequency of hyponatremia in children in intensive care in a reference hospital, and its association with the use of maintenance fluids, as well as the risk factors most often related to this complication.…”