The incidence, risk, presentation, pathophysiology, treatment, and effects of perioperative acute kidney injury.

Purpose: Present clinical updates, current research findings, and consensus statements relevant to the care of the acute kidney injury (AKI) patient.

Principal Findings: Acute kidney injury is one of the most frequent and debilitating complications of surgery and critical illness. Consensus criteria use serum creatinine and urine output measurements to diagnose AKI and allow for objective diagnosis and more accurate comparisons across populations. New serum and urine biomarkers may provide earlier evidence of AKI, but their clinical utility, while increasing, remains limited. Avoidance of nephrotoxins, intravascular fluid management, and maintenance of renal perfusion are the mainstays of preventive management and treatment of AKI. Optimal timing for the initiation of renal replacement therapy is controversial and remains under investigation.

Conclusions: Acute kidney injury continues to affect large numbers of patients receiving surgery or in the intensive care unit, but specific advances in resuscitation techniques, endpoint refinements, epidemiology, biomarkers, and pathology are providing the necessary framework to reduce AKI and associated morbidity.