Intravenous Amino-acid Infusion to Prevent Acute Kidney Injury after Cardiac Surgery: A Review of the Evidence.

Abstract

Acute kidney injury (AKI) is a frequent and important complication of cardiac surgery. Decreased perfusion is a key mechanism. Such decreased perfusion may be attenuated by intravenous amino acids (AA) through recruitment of renal functional reserve. We performed a PubMed search of all articles published from 1980 to August 30, 2024, combining in the search criteria of "renal functional reserve", "amino acids", "cardiac surgery" and "cardiopulmonary bypass" using MEDLINE (PubMed), Embase, and the Cochrane Central Register of Clinical Trials. We included studies, describing the effect of AA on renal functional reserve and studies of adult cardiac surgery patients with information on renal function. We developed a narrative review. Multiple experimental and human studies over > 40 years have recurrently and consistently shown that the administration of an oral protein load or intravenous AA increase renal blood flow and glomerular filtration rate by > 30%. Moreover, several pilot investigations in cardiac surgery with cardiopulmonary bypass have consistently shown renal benefits with intravenous AA. Finally, a pivotal trial of 3511 cardiac surgery patients (the PROTECTION trial) recently confirmed such beneficial effects in a double-blind multicenter international setting. Intravenous AA consistently recruit renal functional reserve and improve kidney function in cardiac surgery patients. These findings have been confirmed by the PROTECTION trial. Intravenous AA therapy is the only proven treatment to prevent and/or attenuate the severity of cardiac surgery associated AKI.