Chloride-restrictive intravenous fluids reduce risk for kidney injury

By medwireNews Reporters

The restrictive use of chloride in intravenous (iv) fluids reduces the risk for acute kidney injury (AKI) and renal replacement therapy (RRT), research shows.

The use of the chloride-restrictive iv strategy was also associated with a smaller increase in mean creatinine levels.

There is now a need to "exert prudence" in the administration of fluids with supraphysiologic concentrations of chloride, especially in critically ill patients with signs of, or at risk for, acute renal dysfunction, according to Rinaldo Bellomo (Monash University, Victoria, Australia) and colleagues.

Published in JAMA, the prospective, "before-and-after" pilot study included approximately 1500 patients treated at a tertiary intensive care unit (ICU).

During the control period, 760 patients admitted to the ICU received standard iv fluids. After a 6-month phase-out period, 773 patients were treated with a chloride-restrictive solution.

In place of chloride-rich fluids, a lactated crystalloid solution, a balanced buffered solution, and a 20% albumin solution were used. Chloride-rich fluids were only available with a prescription from a specialist for specific conditions, such as hyponatremia.

Chloride administration decreased from 694 mmol per patient during the control period to 496 mmol per patient with the use of chloride-restrictive fluids.

Mean serum creatinine level increase was 22.6 µmol/L during the control period and 14.8 µmol/L during the chloride-restrictive intervention period.

Regarding outcomes, the rate of AKI decreased from 14.0% during the chloride-rich control period to 8.4% during the intervention period, a statistically significant reduction.

The use of RRT was 10% during the control period compared with 6.3% in the intervention period, also a significant reduction.

After adjusting for multiple confounding variables, including disease severity, outcome ascertainment, baseline kidney function, and the amount of iv fluid administered, the risk for AKI was 48% lower when the chloride-restrictive iv fluid was used compared with the control period.

Similarly, the risk for RRT was 48% lower during the intervention period compared with the control period.

The researchers say that the chloride-restrictive strategy deserves to be tested in other trials, as well as in other healthcare systems and different ICUs, given the benefits observed in this study.

In an editorial, however, Sushrut Waikar and Wolfgang Winkelmayer (Brigham and Women's Hospital, Boston, Massachusetts, USA) say that deciphering which component of the intervention was responsible for the benefit is impossible.

In addition to less chloride, there was also a lower administration of sodium and a greater administration of buffers, such as lactate, acetate, and gluconate, they say.

The results, however, are important and deserve to be followed up, say the editorialists, and should help focus attention on the formulation of iv fluids.

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.