Warning against colloids in fluid resuscitation

By Eleanor McDermid, Senior medwireNews Reporter

Hydroxyethyl starch (HES) offers no benefits over saline for fluid resuscitation in critically ill patients and may have renal consequences, shows a randomized trial.

"Thus, the selection of resuscitation fluid in critically ill patients requires careful consideration of its safety, its potential effect on patient-centered outcomes, and its cost," comment lead researcher John Myburgh (George Institute for Global Health, Sydney, Australia) and team.

The study, which appears in The New England Journal of Medicine, involved 7000 patients admitted to intensive care units (ICUs) in 32 Australian and New Zealand hospitals. In all, 18.0% of patients randomly assigned to receive HES for all their fluid resuscitation needs died within 90 days of randomization, as did 17.0% of those assigned to receive saline, which was not a significant difference.

Mortality was the primary study outcome, but the researchers say: "A fundamental reason for conducting our study was to determine whether currently used HES solutions increased the risk of acute kidney injury in ICU patients."

Several previous studies suggested that HES use could affect renal outcomes, but these mostly focused on concentrated HES solutions with high molecular weight and a high molar substitution ratio. The findings of Myburgh et al indicate that the risk is also present with the type of HES solutions usually used in clinical practice, in this case a 6% HES solution, with a molecular weight of 130 kD and a molar substitution ratio of 0.4.

Renal replacement therapy was needed for 7.0% of patients assigned to the HES group, compared with 5.8% of those assigned to receive saline. The 21% relative difference tended toward statistical significance (confidence interval 1.00‑1.45; p=0.04). But in an apparent contradiction, the risk for renal injury was significantly reduced in the HES versus saline groups (34.6 vs 38.0%), as was the risk for renal dysfunction (54.0 vs 57.3%), based on the RIFLE (risk, injury, failure, loss, and end-stage kidney injury) measure.

In a post-hoc analysis of the two components of the RIFLE measure, the team found that HES treatment had a beneficial effect on urine output, increasing this in patients with mild kidney injury. But it also increased serum creatinine levels in all patients, "suggesting a progressive reduction in creatinine clearance and more severe acute kidney injury."

Finally, patients in the HES group had significantly more adverse events than those in the saline group (5.3 vs 2.8%), most commonly pruritus and rash, which the team says is consistent with findings of "increased tissue accumulation of HES within the reticuloendothelial system."

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.