Amino acids for renal protection: time to implement in clinical practice

Acute kidney injury (AKI) is a common complication observed in both surgical and critical care settings. The PROTECTION trial, published in the New England Journal of Medicine, showed that short-term low-dose infusions of amino acids (AA) reduced the rate of both any-stage and severe AKI in more than 3,500 cardiac surgery patients. Its publication resulted in the inclusion of AA in the European guidelines for the management of adult cardiac surgery with cardiopulmonary bypass and changes in clinical practice worldwide. This rapid dissemination has raised practical questions regarding patient selection, formulation choice, dosages, and duration of infusion. In this narrative review, we used the "Wh-questions" framework to provide a clear and structured overview on perioperative AA administration. We outline the historical background of AA-mediated renal protection, the pathophysiological context, and the available AA formulations most commonly used in clinical studies. In addition to the conclusive evidence in cardiac surgery, data supporting potential benefits in other high-risk populations, including urological surgery patients and those receiving temporary mechanical circulatory support, are growing. Importantly, recent insights suggest that clinicians must not exceed a 48-hour infusion. Finally, a reduction in hospitalization costs associated with AA infusions has been demonstrated by a recent health economic analysis. Overall, AA infusions represent a simple, safe, and inexpensive intervention that is effective at reducing AKI. These data further support their immediate adoption in routine clinical practice.