Perioperative Amino Acid Infusion and Renal Outcomes in Cardiac Surgery

Background: Acute kidney injury (AKI) is a common complication after cardiac surgery, associated with increased morbidity and mortality, and caused by reduced renal perfusion during surgery. Intravenous amino acid infusion is a potential preventative strategy to enhance renal blood flow and glomerular filtration rate. However, its efficacy in reducing the incidence of AKI remains to be established. Research Question: This meta-analysis sought to evaluate the efficacy of perioperative intravenous amino acid infusion in reducing the incidence of AKI in cardiac surgery patients. Methods: We systematically searched PubMed, Embase, and Cochrane CENTRAL through March 2026 for randomized controlled trials (RCTs) comparing perioperative intravenous amino acid infusion with standard care in adult cardiac surgery patients. The primary outcome was the incidence of AKI. Secondary outcomes included duration of AKI and other complications. Data were analyzed using R (version 4.5.3). Pooled risk ratios (RRs) were estimated using random-effects models, with heterogeneity assessed by the I 2 statistic. Sensitivity and subgroup analyses were performed, and publication bias was visualized via funnel plots. Results: A total of 7 RCTs involving 4,629 patients met the inclusion criteria. Perioperative intravenous amino acid infusion significantly reduced AKI incidence after cardiac surgery (RR 0.72, 95% CI 0.55-0.95, p=0.02). It reduced the risk of stage 1 AKI (RR 0.87, 95% CI 0.78-0.97, p=0.01) and stage 3 AKI (RR 0.52, 95% CI 0.34-0.80, p=0.003), but not stage 2 AKI (RR 1.22, 95% CI 0.67- 2.21, p=0.51). Length of hospital stay was reduced, though this did not reach statistical significance (mean difference -2.14 days, p=0.06). Amino acid infusion significantly increased postoperative urine output (mean difference +0.45 L, p<0.0001). There were no significant differences in post-operative outcomes, including renal replacement therapy use, stroke, atrial fibrillation, ventricular fibrillation, ICU stay, or AKI duration. Conclusion: Perioperative intravenous amino acid infusion is associated with a reduced risk of AKI in patients undergoing cardiac surgery. These findings suggest a potential nephroprotective role, with larger scale studies needed to establish its safety profile.