Definitions of AKI after Cardiac Surgery

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Yaqub S., Hashmi S., Kazmi M.K., Aziz Ali A., Dawood T., Sharif H.: A Comparison of AKIN, KDIGO, and RIFLE Definitions to Diagnose Acute Kidney Injury and Predict the Outcomes after Cardiac Surgery in a South Asian Cohort. Cardiorenal Medicine DOI 10.1159/000523828


Various definitions of acute kidney injury (AKI) are in common use, globally. But comparisons of the utility of these definitions for AKI following cardiac surgery have come to differing conclusions.

Yaqub and co-workers have conducted a single-center retrospective review of the receiver operating characteristics of the Acute Kidney Injury Network (AKIN), Kidney Disease Improving Global Outcomes (KDIGO), and the Risk, Injury, Failure, Loss, End-stage kidney disease (RIFLE) in 1,508 subjects undergoing coronary artery bypass surgery during 2015–2019 in South Pakistan. Only changes in serum creatinine were used in applying the definition.

AKI by any definition or stage was found postoperatively in 59% of the subjects – 34% by AKIN, 35% by KDIGO, and 58% by RIFLE. AKIN Stage 2 was found in 8.9%, KDIGO Stage 2 in 10.1%, and RIFLE injury in 13.5% of the subjects. Stage 3 AKI was uncommon by any definition (about 2–3%). RIFLE identified risk in more patients than Stage 1 in either AKIN or KDIGO. Any AKI, regardless of definition or stage, was associated with an increase in 30-day mortality rate, and the RIFLE criterion was superior to both AKIN or KDIGO in the prediction of 30-day mortality rate.

This analysis gives useful insights into the utility of various criteria for the definition of AKI. The question remains if this is generalizable to other settings and other forms of cardiac surgery. The reproducibility of the diagnostic criteria was not studied. It is noteworthy that AKI Stage 3 (AKIN/KDIGO) or loss (RIFLE) was very uncommon in this cohort of subjects.

Richard Glassock


Quoted Karger Article

A Comparison of AKIN, KDIGO, and RIFLE Definitions to Diagnose Acute Kidney Injury and Predict the Outcomes after Cardiac Surgery in a South Asian Cohort