Comparison of various surrogate markers for venous congestion in predicting acute kidney injury following cardiac surgery: A cohort study

Venous congestion has been demonstrated to increase the risk of acute kidney injury (AKI) after cardiac surgery. Although many surrogate markers for venous congestion are currently used in clinical settings, there is no consensus on which marker is most effective in predicting AKI. We evaluated various markers of venous congestion, including central venous pressure (CVP), inferior vena cava (IVC) diameter, portal pulsatility fraction (PPF), hepatic vein flow pattern (HVF), intra-renal venous flow pattern (IRVF), and venous excess ultrasound grading score (VExUS) in adult patients undergoing cardiac surgery to compare their ability in predicting AKI. Among the 230 patients enrolled in our study, 53 (23.0%) developed AKI, and 11 (4.8%) required continuous renal replacement therapy (CRRT). Our multivariate logistic analysis revealed that IRVF, PPF, HVF, and CVP were significantly associated with AKI, with IRVF being the strongest predictor (odds ratio [OR] 2.27; 95% confidence interval [CI], 1.38–3.73). However, we did not observe any association between these markers and CRRT. Venous congestion is associated with AKI after cardiac surgery, but not necessarily with CRRT. Among the markers tested, IRVF exhibits the strongest correlation with AKI. •Venous congestion is associated with CSA-AKI, but not necessarily with CRRT.•The surrogates of venous congestion exhibit varying degrees of correlation with each other.•Among all the congestion surrogates, IRVF may be the most closely associated with CSA-AKI.•IVC is not a valuable variable for both venous congestion and CSA-AKI prediction.•Inclusion of IVC may compromise the effectiveness of VExUS in estimating congestion and predicting CSA-AKI.