Balanced crystalloid solution versus saline in deceased donor kidney transplantation (BEST-Fluids): a pragmatic, double-blind, randomised, controlled trial.

Background: Delayed graft function (DGF) is a major adverse complication of deceased donor kidney transplantation. Intravenous fluids are routinely given to patients receiving a transplant to maintain intravascular volume and optimise graft function. Saline (0·9% sodium chloride) is widely used but might increase the risk of DGF due to its high chloride content. We aimed to test our hypothesis that using a balanced low-chloride crystalloid solution (Plasma-Lyte 148) instead of saline would reduce the incidence of DGF.
Methods: BEST-Fluids was a pragmatic, registry-embedded, multicentre, double-blind, randomised, controlled trial at 16 hospitals in Australia and New Zealand. Adults and children of any age receiving a deceased donor kidney transplant were eligible; those receiving a multi-organ transplant or weighing less than 20 kg were excluded. Participants were randomly assigned (1:1) using an adaptive minimisation algorithm to intravenous balanced crystalloid solution (Plasma-Lyte 148) or saline during surgery and up until 48 h after transplantation. Trial fluids were supplied in identical bags and clinicians determined the fluid volume, rate, and time of discontinuation. The primary outcome was DGF, defined as receiving dialysis within 7 days after transplantation. All participants who consented and received a transplant were included in the intention-to-treat analysis of the primary outcome. Safety was analysed in all randomly assigned eligible participants who commenced surgery and received trial fluids, whether or not they received a transplant. This study is registered with Australian New Zealand Clinical Trials Registry, (ACTRN12617000358347), and ClinicalTrials.gov (NCT03829488).
Findings: Between Jan 26, 2018, and Aug 10, 2020, 808 participants were randomly assigned to balanced crystalloid (n=404) or saline (n=404) and received a transplant (512 [63%] were male and 296 [37%] were female). One participant in the saline group withdrew before 7 days and was excluded, leaving 404 participants in the balanced crystalloid group and 403 in the saline group that were included in the primary analysis. DGF occurred in 121 (30%) of 404 participants in the balanced crystalloid group versus 160 (40%) of 403 in the saline group (adjusted relative risk 0·74 [95% CI 0·66 to 0·84; p<0·0001]; adjusted risk difference 10·1% [95% CI 3·5 to 16·6]). In the safety analysis, numbers of investigator-reported serious adverse events were similar in both groups, being reported in three (<1%) of 406 participants in the balanced crystalloid group versus five (1%) of 409 participants in the saline group (adjusted risk difference -0·5%, 95% CI -1·8 to 0·9; p=0·48).
Interpretation: Among patients receiving a deceased donor kidney transplant, intravenous fluid therapy with balanced crystalloid solution reduced the incidence of DGF compared with saline. Balanced crystalloid solution should be the standard-of-care intravenous fluid used in deceased donor kidney transplantation.
Funding: Medical Research Future Fund and National Health and Medical Research Council (Australia), Health Research Council (New Zealand), Royal Australasian College of Physicians, and Baxter.
Competing Interests: Declaration of interests MGC has received research support from Baxter Healthcare, the manufacturer of Plasma-Lyte 148, via a Baxter Investigator-Initiated Research grant that provided fluids for the BEST-Fluids trial (commercial value of US$36 270). DWJ has received consultancy fees, research grants, speaker's honoraria, and travel sponsorships from Baxter Healthcare and Fresenius Medical Care; consultancy fees from AstraZeneca and AWAK; speaker's honoraria and travel sponsorships from ONO; and travel sponsorships from Amgen. DR, LEH, LAV, EMP, CK, and JV are employees of the sponsor, The University of Queensland. KBD's salary was funded by a Better Evidence and Translation in Chronic Kidney Disease (BEAT-CKD) grant' and she is an employee of the ANZDATA Registry. PAC is the Deputy Executive Officer of the ANZDATA Registry. CMH has received fees for research committee activities from Janssen and GlaxoSmithKline paid to her institution; personal fees from Otsuka; research grants from Fresenius, Shire, and PKD Australia outside the submitted work; and research grants from Baxter and the National Health and Medical Research Council of Australia related to the current project. LW works in the Department of Anaesthesia at Austin Health, which has received funding from Baxter Healthcare for investigator-initiated clinical research. PFM has received honoraria for presentations on behalf of AstraZeneca and consultancy fees from Vifor. LW has received honoraria from Baxter Healthcare for consulting activities. All LW's fluid-related research, including study design, execution, data collection, analysis, and reporting, has been conducted independently of Baxter Healthcare and other commercial entities. ZHE has received consultancy fees and travel sponsorships from AstraZeneca. WHL has received honoraria from Alexion and education or research grants from Astellas. SJC has received research support, travel support, speaker fees, or honoraria from AstraZeneca, Bayer, CSL-Behring, Novartis, and Takeda. All other authors declare no competing interests.
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