Comparison of renal region, cerebral and peripheral oxygenation for predicting postoperative renal impairment after CABG

Abstract

Patients undergoing coronary artery bypass grafting (CABG) are at risk of developing postoperative renal impairment, amongst others caused by renal ischemia and hypoxia. Intra-operative monitoring of renal region tissue oxygenation (SrtO2) might be a useful tool to detect renal hypoxia and predict postoperative renal impairment. Therefore, the aim of this study was to assess the ability of intra-operative SrtO2 to predict postoperative renal impairment, defined as an increase of serum creatinine concentrations of > 10% from individual baseline, and compare this with the predictive abilities of peripheral and cerebral tissue oxygenation (SptO2 and SctO2, respectively) and renal specific tissue deoxygenation. Forty-one patients undergoing elective CABG were included. Near-infrared spectroscopy (NIRS) was used to measure renal region, peripheral (thenar muscle) and cerebral tissue oxygenation during surgery. Renal region specific tissue deoxygenation was defined as a proportionally larger decrease in SrtO2 than SptO2. ROC analyses were used to compare predictive abilities. We did not observe an association between tissue oxygenation measured in the renal region and cerebral oxygenation and postoperative renal impairment in this small retrospective study. In contrast, SptO2 decrease > 10% from baseline was a reasonable predictor with an AUROC of 0.767 (95%CI 0.619 to 0.14; p = 0.010). Tissue oxygenation of the renal region, although non-invasively and continuously available, cannot be used in adults to predict postoperative renal impairment after CABG. Instead, peripheral tissue deoxygenation was able to predict postoperative renal impairment, suggesting that SptO2 provides a better indication of 'general' tissue oxygenation status.Registered at ClinicalTrials.gov: NCT01347827, first submitted April 27, 2011.

Keywords: Acute kidney injury; Cerebral oxygenation; Coronary artery bypass grafting (CABG); Postoperative renal impairment; Renal oxygenation.

Conflict of interest statement

INdK, MP and JJV have no conflict of interest to declare. ARA is an editor of the British Journal of Anaesthesia. He reports reimbursement for consultancy work and paid phase 1 research by The Medicines Company (Parsippany, NJ, USA) and Rigel Inc (San Francisco, CA); unrestricted research funding and reimbursenment for consultancy work from Carefusion (BD; Eysins, Switzerland) and Philips (Eindhoven, The Netherlands); receipt of consultancy fees from Janssen Pharma (Johnson and Johnson; Beerse, Belgium), Ever Pharma (Unterach am Attersee, Austria), PAION (Aachen, Germany) and Orion (Espoo, Finland). All payments made to institution. MAM received grants from AtriCure (Mason, Ohio, USA), Abbott Laboratories (Chicago, Illinois, USA), Edwards Lifesciences (Irvine, California, USA), Getinge Consultancy (Göteborg, Sweden), LivaNova PLC (London, United Kingdom) and Medtronic (Dublin, Ireland). TWLS received research grants and honoraria from Edwards Lifesciences (Irvine, CA, USA) and Masimo Inc. (Irvine, CA, USA) for consulting and lecturing and from Pulsion Medical Systems SE (Feldkirchen, Germany) for lecturing. TWLS is Editor-in-Chief of the Journal of Clinical Monitoring and Computing but had no role in the handling of this manuscript.

© 2021. The Author(s).

Figures

Fig. 1

Example of the calculation of renal region specific tissue deoxygenation. The grey area is the area under the threshold (AUT; (%min)) of renal region specific tissue deoxygenation, which was calculated by subtracting the SrtO2 in % from baseline (renal tissue (blue line)) from the SptO2 in % from baseline (peripheral tissue (orange line))