Early predictive value of renal resistance index combined with sublingual microcirculation for trauma-related acute kidney injury

Yao Xuan; Liu Jing; Yang Xiaoping; Ma Bei; Chen Xi; Yang Yu

doi:10.3969/j.issn.1009-4237.2024.10.010

Abstract：Objective To explore the value of renal resistance index(RRI)combined with sublingual mi-crocirculation in early prediction of trauma-related acute kidney injury(AKI).Methods This prospective study analyzed 45 trauma patients admitted to the ICU of People's Hospital of Chongqing Liangjiang New Area from Sep.2023 to Mar.2024.Among them,26 were males and 19 were females.Patients aged 18-94 years,mean 64.8 years.There were 18 cases of road traffic accidents,15 falls from height,8 ground-level falls,2 crush injuries,and 2 stab wounds.Doppler flow spectrum of the interlobar artery was obtained and RRI was measured.Sublingual microcircu-lation was monitored to obtain microcirculation images of the sublingual region to measure microcirculation indexes,including microvascular flow index(MFI),flow heterogeneity index(FHI),proportion of perfused vessels(PPV),perfused vascular density(PVD),and total vascular density(TVD).Depending on whether AKI occurred within 72 h after injury,patients were divided into AKI group(25 cases)and non-AKI group(20 cases).SPSS 22.0 was used to compare each index between the two groups.Binary Logistic regression analysis was adopted to screen rele-vant factors of AKI in trauma patients.ROC curve was drawn to evaluate the efficacy of these indicators to predict AKI.Results It was found that RRI in AKI group was significantly higher than that in non-AKI group[0.74(0.70,0.76)vs.0.65(0.62,0.70),P＜0.001].As for the indicators of sublingual microcirculation,the AKI group re-vealed much higher FHI[0.56(0.35,1.07)vs.0.04(0,2.22),P＜0.05]and much lower MFI[2.18(1.4,2.55)vs.2.98(2.84,3.00)],PPV[78.9％(40.3％,100％)vs.100％(99.2％,100％)]and PVD(mm/mm2,11.00±5.43 vs.14.47±3.76,all P＜0.05),but non-significant difference for TVD(mm/mm2,15.12±3.40 vs.14.63±3.54,P=0.640).Binary Logistic regression analysis showed that shock,RRI,MFI,FHI,PPV and PVD were statis-tically significant influencing factors for AKI(all P＜0.05).The AUC(95％CI)to predict AKI in trauma patients was 0.851(0.713,0.939)for RRI,0.754(0.550,0.860)for MFI and 0.781(0.631,0.891)for PVD,and their optimal cut-off were 0.72,2.70 and 10.80,respectively.When the three factors were used combinedly,the AUC(95％CI)reached 0.872(0.736,0.953),with a sensitivity of 88％and specificity of 84％.Conclusion The renal ultrasound index of RRI and sublingual microcirculation indexes of MFI and PVD are associated with the incidence of trauma-related AKI.Combined use of the three indexes shows a high predictive value and can be a potential pre-dictor of trauma-related AKI.