Acute kidney injury (AKI) among hospitalized patients is common, consequential, and costly. Annually in the United States, approximately 10% of the estimated 5 million hospitalizations are complicated by AKI, with 0.4% of cases severe enough to require dialysis. Among patients with AKI requiring extracorporeal kidney support (dialysis), in-hospital mortality rates are consistently in excess of 20%, and may exceed 40% when accompanied by nonrenal organ system failure.1-3 Acute kidney injury results in prolonged hospital stay, and is associated with marked increase in hospital costs, with attributable costs estimated to be between $5 billion and $10 billion annually.3-5 Moreover, AKI has been linked with increased longer-term risks of chronic kidney disease (CKD), another condition associated with poor outcomes and high health care resource consumption,6 as well as of higher risks of hypertension.7