There was no significant difference in the incidence of acute kidney injury or failure for intensive care unit (ICU) patients who received a buffered crystalloid or saline for fluid therapy, according to a study appearing in JAMA. The study is being released to coincide with its presentation at the 28th annual congress of the European Society of Intensive Care Medicine.

The administration of intravenous fluids to increase intravascular volume or maintain hydration is a frequent intervention in the ICU, although the choice of fluid remains controversial. Globally, 0.9 percent sodium chloride (saline) is the most commonly used resuscitation fluid. However, despite its widespread use, emerging data provide uncertainty about the safety of saline in patients who are critically ill, with a concern that the high chloride content may contribute to the development of acute kidney injury (AKI), according to background information in the article.

One alternative to saline is a buffered crystalloid solution with an electrolyte composition that more closely resembles that of plasma, such as the prototype compound sodium lactate solutions or proprietary "buffered" or "balanced" crystalloid solutions. Observational data suggest that buffered crystalloids may be associated with a decreased risk of AKI and of death compared with saline. Paul Young, F.C.I.C.M., of the Medical Research Institute of New Zealand, Wellington, and colleagues studied 2,278 patients who were receiving treatment in 4 ICUs in New Zealand and requiring crystalloid fluid therapy. Of these patients, 1,152 of 1,162 patients (99 percent) receiving buffered crystalloid and 1,110 of 1,116 patients (99.5 percent) receiving saline were analyzed.

In the buffered crystalloid group, 102 of 1,067 patients (9.6 percent) developed AKI within 90 days after enrollment compared with 94 of 1,025 patients (9.2 percent) in the saline group. In the buffered crystalloid group, renal replacement therapy (dialysis) was used in 38 of 1,152 patients (3.3 percent) compared with 38 of 1,110 patients (3.4 percent) in the saline group. Overall, 7.6 percent of patients in the buffered crystalloid group and 8.6 percent of patients in the saline group died in the hospital.

"Further large randomized clinical trials are needed to assess efficacy in higher-risk populations and to measure clinical outcomes such as mortality," the authors write.

Editorial: Assessing Toxicity of Intravenous Crystalloids in Critically Ill Patients

In an accompanying editorial, John A. Kellum, M.D., of the University of Pittsburgh, and Andrew D. Shaw, M.B., F.R.C.A., of the Vanderbilt University School of Medicine, Nashville, comment on the findings of this study.

"The results of the trial by Young et al provide reassurance that neither 0.9 percent saline nor a low-chloride electrolyte solution appears to be particularly hazardous when the total dose used in patients at low to moderate risk is about 2 L. This is an important contribution to the care of patients in the ICU. However, the large body of 'circumstantial' evidence that points to a harm signal for saline - with scant, if any, evidence of comparative benefit - should behoove intensivists and other clinicians to proceed with caution when ordering intravenous fluids."