Observational Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 6, 2023; 11(16): 3791-3801
Published online Jun 6, 2023. doi: 10.12998/wjcc.v11.i16.3791
Incidence and peri-operative risk factors for development of acute kidney injury in patients after cardiac surgery: A prospective observational study
Stavros Dimopoulos, Georgios Zagkotsis, Charalambia Kinti, Niki Rouvali, Magda Georgopoulou, Mariantzela Mavraki, Androniki Tasouli, Efterpi Lyberopoulou, Antonios Roussakis, Ioannis Vasileiadis, Serafim Nanas, Andreas Karabinis
Stavros Dimopoulos, Charalambia Kinti, Niki Rouvali, Magda Georgopoulou, Mariantzela Mavraki, Androniki Tasouli, Efterpi Lyberopoulou, Antonios Roussakis, Andreas Karabinis, Department of Cardiac Surgery Intensive Care Unit, Onassis Cardiac Surgery Center, Athens 17674, Greece
Stavros Dimopoulos, Georgios Zagkotsis, Ioannis Vasileiadis, Serafim Nanas, Department of Clinical Ergospirometry, Exercise and Rehabilitation Laboratory, National and Kapodistrian University of Athens, Athens 10676, Greece
Author contributions: Dimopoulos S conceptualized and designed the study. Karabinis A supervised the study; Dimopoulos S, Zagkotsis G, Tasouli A, Vasileiadis I and Nanas S were involved in the data curation and analysis, projet administration and provided scientific review; Dimopoulos S, Kinti C, Rouvali N, Georgopoulou M, Mavraki M and Lyberopoulou E performed the research and collected the data; Dimopoulos S and Zagkotsis G wrote the paper, reviewed, edited and revised the final version of the manuscript. All authors have read and approved the final manuscript.
Institutional review board statement: The study was reviewed and approved by Ethics Committee of the Onassis Cardiac Surgery Center, Athens, Greece (Number Id: 663/12.12.19.
Informed consent statement: All study participants provided informed consent and the study was carried out in accordance with the ethical standards set by the Declaration of Helsinki.
Conflict-of-interest statement: There are no conflicts of interest to report.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Stavros Dimopoulos, PhD, Chief Doctor, Consultant Physician-Scientist, Director, Doctor, Research Scientist, Staff Physician, Department of Cardiac Surgery Intensive Care Unit, Onassis Cardiac Surgery Center, Athens, 17674, Greece. stdimop@med.uoa.gr
Received: February 8, 2023
Peer-review started: February 8, 2023
First decision: March 14, 2023
Revised: March 28, 2023
Accepted: May 4, 2023
Article in press: May 4, 2023
Published online: June 6, 2023

Patients admitted to intensive care unit (ICU) after cardiac surgery develop acute kidney injury (AKI) immediately post-operation. We hypothesized that AKI occurs mainly due to perioperative risk factors and may affect outcome.


To assess peri-operative risk factors for AKI post cardiac surgery and its relationship with clinical outcome.


This was an observational single center, tertiary care setting study, which enrolled 206 consecutive patients, admitted to ICU after cardiac surgery. Patients were followed-up until ICU discharge or death, in order to determine the incidence of AKI, perioperative risk factors for AKI and its association with outcome. Univariate and multivariate logistic regression analysis was performed to assess predictor variables for AKI development.


After ICU admission, 55 patients (26.7%) developed AKI within 48 h. From the logistic regression analysis performed, high EuroScore II (OR: 1.18; 95%CI: 1.06-1.31, P = 0.003), white blood cells (WBC) pre-operatively (OR: 1.0; 95%CI: 1.0-1.0, P = 0.002) and history of chronic kidney disease (OR: 2.82; 95%CI: 1.195-6.65, P = 0.018) emerged as independent predictors of AKI among univariate predictors. AKI that developed AKI had longer duration of mechanical ventilation [1113 (777–2195) vs 714 (511–1020) min, P = 0.0001] and ICU length of stay [70 (28–129) vs 26 (21–51) h, P = 0.0001], higher rate of ICU-acquired weakness (16.4% vs 5.3%, P = 0.015), reintubation (10.9% vs 1.3%, P = 0.005), dialysis (7% vs 0%, P = 0.005), delirium (36.4% vs 23.8%, P = 0.001) and mortality (3.6% vs 0.7%, P = 0.046).


Patients present frequently with AKI after cardiac surgery. EuroScore II, WBC count and chronic kidney disease are independent predictors of AKI development. The occurrence of AKI is associated with poor outcome.

Keywords: Acute kidney injury, Renal failure, Cardiac surgery, Predisposing factors, Prognosis, Outcome

Core Tip: Acute kidney injury (AKI) may develop in patients after cardiac surgery. In this observational study we assessed the incidence, the peri-operative risk factors for AKI occurrence and its association with outcome in patients after cardiac surgery post- intensive care unit (ICU) admission. The results of the study have shown that AKI occurs frequently after cardiac surgery. EuroScore II, history of chronic kidney disease and white blood cell count are independent predictors of AKI development. The presence of AKI was associated with poor outcome in terms of mechanical ventilation duration, ICU length of stay, rate of dialysis, reintubation, ICU-acquired weakness, delirium and mortality.