Cardiac surgery-associated acute kidney injury: putting together the pieces of the puzzle.
BACKGROUND
Acute kidney injury (AKI) is a common problem in the context of cardiac surgery. There are both similarities and differences with AKI occurring in other clinical scenarios. In this paper, we discuss those aspects of AKI that are particular to cardiac surgery-associated AKI (CSA-AKI), with emphasis on recent advances in the field.


METHODS
We summarize the recent literature relating to CSA-AKI, focusing on epidemiology, pathophysiology, risk prediction and prevention.


RESULTS
The Acute Kidney Injury Network (AKIN) criteria for the diagnosis and severity of AKI are a useful framework within which future epidemiological studies of AKI may be considered. Percent change in serum creatinine remains a sensitive and clinically relevant continuous measure of declining kidney function. New biomarkers of diagnosis are currently being validated, while biomarkers of prognosis are lacking. Notably, intraoperative antifibrinolytic therapy effects invalidate 'tubular proteinuria' biomarkers. Better characterization of genetic predisposition to CSA-AKI may enhance risk prediction, since currently available clinical models lack precision, particularly for the important clinical endpoint of new renal replacement therapy.


CONCLUSIONS
CSA-AKI remains a clinically relevant problem for 5-10% of cardiac surgery patients and is associated with adverse clinical outcomes. Small changes in serum creatinine are important and should not be ignored. The overall incidence of new dialysis after cardiac surgery remains low.
Shaw
Andrew
A
Division of Cardiothoracic Anesthesia and Critical Care Medicine, Duke University Medical Center, Durham, NC 27710, USA. andrew.shaw@duke.edu
Swaminathan
Madhav
M
Stafford-Smith
Mark
M
D058186:Acute Kidney Injury / Q000453:epidemiology*; D006348:Cardiac Surgical Procedures / Q000706:statistics & numerical data*; D015984:Causality; D015897:Comorbidity; D006801:Humans; D015994:Incidence; D011183:Postoperative Complications / Q000453:epidemiology*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors