Basic Knowledge about Acute Kidney Injury for Certified Anesthesiologists

Abstract

There are currently three international definitions for acute kidney injury (AKI) : Risk-Injury-Failure-Loss-Endstage renal disease, Acute Kidney Injury Network, and Kidney Disease : Improving Global Outcomes. Incidence of postoperative AKI is highest in patients undergoing transplantation followed by cardiac/aortic surgery, major abdominal surgery, and noncardiac minor surgery. A wide variety of risk factors for postoperative AKI are known including comorbidities (e.g., chronic renal disease, hypertension, peripheral vascular disease), pre- and intraoperative medications (e.g., contrast agents, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers), intraoperative interventions (e.g., cardiopulmonary bypass, transfusion), and intraoperative pathological conditions (e.g., massive hemorrhage, fluid overload). Anesthesiologists are expected to play an important role in preventing postoperative AKI from occurring by maintaining optimal intravascular volume status and optimal hemodynamic status, and by not administering drugs with possible nephrotoxicity. Oliguria is often encountered during anesthesia because of hemodynamic or hormonal effects of anesthesia drugs, surgical procedures, and positive pressure ventilation. In case of oliguria, risk evaluation based on characteristics of patients and surgical procedures is essential to decide how to cope with it.