Cardiac Surgery-associated Acute Kidney Injury: A Comprehensive Review

Background: Cardiac surgery-associated acute kidney injury (CSA-AKI) is acommon and serious complication occurring within 7 days after cardiac surgery. Withover 2 million cardiac surgeries performed worldwide annually, CSA-AKI incidenceranges from 19% to 43% in adults and up to 64% in neonates, increasing perioperativemortality by 3-8-fold, prolonging hospital stays, and substantially increasinghealthcare costs. Despite advances in perioperative care, CSA-AKI remains a majorclinical challenge due to its multifactorial pathophysiology and limited therapeutic options. Purpose: This review aims to provide a comprehensive and updated overview of CSA-AKI, systematically summarizing current knowledge on its pathophysiology, risk factors, diagnostic criteria, prevention strategies, and treatment options, with particular emphasis on recent advances through 2026. Methods: A comprehensive literature review was conducted by searching electronic databases for relevant clinical studies, systematic reviews, meta-analyses, and guideline updates on CSA-AKI published through 2026. The reviewed literature was analyzed and synthesized across key domains including pathophysiological mechanisms, risk factor classification, diagnostic criteria comparison, and evidence-based prevention and treatment strategies. Conclusions: The pathophysiology of CSA-AKI involves multipleinteracting mechanisms including hypoperfusion, ischemia-reperfusion injury, inflammation, oxidative stress, nephrotoxicity, and genetic susceptibility, with renalhypoperfusion during cardiopulmonary bypass identified as a central mechanism. KDIGO criteria currently offer the highest diagnostic sensitivity among availableclassification systems. Goal-directed perfusion (GDP) strategies maintaining indexedoxygen delivery above targeted thresholds have demonstrated significant reduction in CSA-AKI incidence, with emerging evidence supporting sex-specific optimization. Pharmacological advances, particularly amino acid therapy, have shown a 28%reduction in CSA-AKI incidence with a Class IIa recommendation. Earlyidentification of high-risk patients, optimization of cardiopulmonary bypassmanagement through GDP, and implementation of evidence-based prevention bundlesremain the cornerstones of clinical management. Future research should prioritizetargeted pharmacological therapies, machine learning-based risk prediction models, and adequately powered multicenter trials.