Effect of intraoperative renal artery resistance index in predicting postoperative acute kidney injury after cardiac surgery
Objective To investigate the effect of intraoperative renal artery resistance index(RI)in predicting postoperative acute kidney injury(AKI)in patients undergoing cardiac surgery with cardiopul-monary bypass(CPB).Methods Forty-four patients undergoing elective cardiac surgery with CPB,21 males and 23 females,aged ≥18 years,BMI 18.5-30.0 kg/m2,ASA physical status Ⅰ-Ⅲ,were select-ed.Left renal artery peak systolic velocity(PSV)and end-diastolic velocity(EDV)were measured by transesophageal echocardiography(TEE)20 minutes after general anesthesia induction(T1)and 30 minutes after CPB cessation(T2).RI was calculated as(PSV-EDV)/PSV.Patients were divided into two groups:the AKI group and the non-AKI group,according to whether occurred AKI by the diagnostic criteria of the kidney disease:improving global outcomes organization(KDIGO).Logistic multivariate regression analysis was performed to identify the risk factors for AKI occurrence.Results Sixteen patients(36%)oc-curred AKI.Compared with the non-AKI group,the CPB duration and aortic cross-clamp duration were sig-nificantly prolonged(P<0.05),the renal artery RI at T,and T2 were significantly increased in the AKI group(P<0.05).Multivariate logstic analysis showed that RI at T2 was an independent risk factor for AKI occurrence after cardiac surgery,the AUC was 0.893(95%CI 0.794-0.991,P<0.010),the sensitivity and specificity were 84.5%and 78.6%,respectively,and the cut-off value was 0.720.Conclusion Intra-operative renal artery RI in patients undergoing cardiac surgery is an independent risk factor for AKI after cardiac surgery,and renal artery RI>0.720 at 30 minutes after CPB cessation can serve as a predictive in-dicator for AKI after cardiac surgery.