Assessment of the renal functional reserve for predicting the development of cardiosurgically associated acute kidney injury (literature review)

Introduction. Acute kidney injury (AKI) is a common complication of cardiac surgery. Despite a variety of proposed nephroprotective strategies, clinical data on their effectiveness remain inconsistent, and current diagnostic methods often fail to detect subclinical renal dysfunction in a timely manner. Under these circumstances, renal functional reserve (RFR) has gained attention as a potential tool for early prediction and prevention of AKI.

The objective was to summarize current data on renal functional reserve, methods of its assessment and its clinical significance in the prediction and prevention of cardiac surgery associated AKI.

Materials and Methods. A literature review was conducted using scientific publications retrieved from PubMed, Scopus, Web of Science, and eLIBRARY databases, covering the period from 1983 to March 2025. Included were original research articles and reviews focused on the physiology of renal functional reserve (RFR), methods for its assessment, clinical applications, and nephroprotective potential. Only studies involving adult patient populations were considered.

Results. RFR reflects the kidneys’ ability to adapt to physiological stress by increasing the glomerular filtration rate. This section presents the mechanisms underlying RFR activation, methods of its assessment (including protein load and amino acid infusion), and clinical studies demonstrating the prognostic value of RFR and its potential use in nephroprotective strategies.

Conclusion. RFR is a promising biomarker for preoperative risk stratification and the development of individualized nephroprotection strategies in cardiac surgical patients.

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