Wigmore, G.J.Deane, A.M.Presneill, J.J.Serpa Neto, A.Eastwood, G.Maiden, M.J.Bihari, S.Baker, R.A.Bennetts, J.S.Ghanpur, R.Anstey, J.R.Raman, J.Bellomo, R.2025-07-162025-07-162025Journal of Cardiothoracic and Vascular Anesthesia, 2025; 39(4):967-9741053-07701532-8422https://hdl.handle.net/2440/145996Objective: To compare the effects of fluid bolus therapy (FBT) with 20% albumin to crystalloid FBT on the incidence of cardiac surgery–associated acute kidney injury (CSA-AKI) and its severity and duration. Design: Secondary analysis of the multicenter, parallel-group, open-label, randomized HAS FLAIR-II trial. Setting: Six intensive care units. Participants: Patients who required clinician-determined FBT after cardiac surgery requiring cardiopulmonary bypass. Interventions: Patients were randomized to receive FBT with 20% albumin (up to 400 mL/day) or crystalloid fluid for all FBTs in the intensive care unit. Measurements and Main Results: A total of 452 patients were included in the modified intention-to-treat population (224 in the 20% albumin group and 228 in the crystalloid group). AKI occurred in 54 (24%) patients in the 20% albumin group and 50 (22%) in the crystalloid group (odds ratio: 1.13, 95% confidence interval [CI]: 0.73 to 1.76). However, in patients who developed stages 2 and 3 AKI, those allocated to 20% albumin had a significantly lower median time-weighted average (TWA) creatinine: 144 µmol/L (interquartile range [IQR]: 109 to 162) versus 254 µmol/L (IQR: 182 to 294) than the crystalloid group (difference –105 µmol/L, [95% CI –170 to –41], p = 0.003) and a lower peak serum creatinine (–110 µmol/L [–189 to –32], p = 0.01). The reduced TWA creatinine in the 20% albumin group was seen in patients with both a low (p = 0.04) and normal preoperative serum albumin concentration (p < 0.001). Conclusions: FBT with 20% albumin compared with crystalloid-based regimen did not reduce the occurrence of AKI in patients after cardiac surgery. However, it reduced the severity and duration of stages 2 and 3 AKI.en© 2025 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)acute kidney injury; albumin; cardiac surgery; critical care; creatinine; azotemiaHumansPostoperative ComplicationsAlbuminsIsotonic SolutionsFluid TherapyCardiac Surgical ProceduresAgedMiddle AgedFemaleMaleAcute Kidney InjuryCrystalloid SolutionsJournal article10.1053/j.jvca.2024.12.041726870Deane, A.M. [0000-0002-7620-5577]Maiden, M.J. [0000-0003-4345-3213]