Résumé
Objective:To explore the predictive value of renal resistive index (RRI) joint with semiquantitative power Doppler ultrasound (PDU) score to acute kidney injury (AKI) in non-septic critically ill patients.Methods:This prospective observational study enrolled non-septic critically ill patients admitted to the Emergency Intensive Care Unit of Cangzhou Central Hospital from January 2018 to August 2019. In addition to general data, RRI and PDU scores were measured with medical ultrasonic instrument within 6 h after admission. Renal function was assessed on the 5th day in accordance with kidney disease: Improving Global Outcomes criteria. The patients who progressed to AKI stage 3 within 5 days after admission were classified into the AKI 3 group, and the rest were classified into the AKI 0-2 group. The difference of each index was compared between the two groups in non-septic critically ill patients and patients with acute heart failure (AHF). Normal distributed continuous variables were compared using independent sample t-tests, whereas Mann-Whitney U tests were used to examine the differences in variables without a normal distribution. Categorical data were compared with the Chi-square test. Receiver operator characteristic curves were plotted to examine the values of RRI, PDU score, RRI-RDU/10 (subtraction of RRI and 1/10 of PDU score), RRI/PDU (the ratio of RRI to PDU score), and RRI+PDU (the prediction probability of the combination of RRI and PDU score for AKI stage 3 obtained by logistic regression analysis) in predicting AKI 3. Delong's test was used to compare the area under the curve (AUC) between predictors. Results:A total of 110 non-septic critically ill patients (51 patients with no AKI, 21 with AKI stage 1, 11 with AKI stage 2, and 27 with AKI stage 3) were recruited. Among them, there were 63 patients with AHF (21 patients with no AKI, 15 with AKI stage 1, 7 with AKI stage 2, and 20 with AKI stage 3). Among the non-septic critically ill patients as well as its subgroup of AHF, compared with the AKI 0-2 group, acute physiology and chronic health evaluation-Ⅱ score, sequential organ failure assessment score, arterial lactate concentration, mechanical ventilation rate, proportion of vasoactive drugs, 28-day mortality, serum creatinine, RRI, RRI-RDU/10, RRI/PDU, RRI+PDU, and rate of continuous renal replacement therapy were higher in the AKI 3 group, and urine output and PDU score were lower ( all P<0.05). As for non-septic critically ill patients, RRI/PDU [AUC=0.915, 95% confidence interval ( CI): 0.846-0.959, P<0.01] and RRI+PDU (AUC=0.914, 95% CI: 0.845-0.959, P<0.01) performed best in predicting AKI 3, and the AUCs were higher than RRI (AUC=0.804, 95% CI: 0.718-0.874, P<0.01) and PDU score (AUC=0.868, 95% CI: 0.791-0.925, P<0.01). The optimal cutoff for RRI/PDU was > 0.355 (sensitivity 92.6%, specificity 81.9%, Youden index 0.745). The predictive value of RRI-RDU/10 for AKI 3 (AUC=0.899, 95% CI: 0.827-0.948, P<0.01) was also better than RRI and PDU scores, but slightly worse than RRI/PDU and RRI+PDU, with statistically difference only between RRI and RRI-RDU/10 ( P<0.05). As for patients with AHF, RRI/PDU (AUC=0.962, 95% CI: 0.880-0.994, P<0.01) and RRI+PDU (AUC=0.962, 95% CI: 0.880-0.994, P<0.01) also performed best in predicting AKI 3, and the AUCs were higher than RRI (AUC=0.845, 95% CI: 0.731-0.924, P<0.01) and PDU score (AUC=0.913, 95% CI: 0.814-0.969, P<0.01) with statistically differences (all P<0.05). The optimal cutoff for RRI/PDU was > 0.360 (sensitivity 95.0%, specificity 90.7%, Youden index 0.857). The predictive value of RRI-RDU/10 for AKI 3 (AUC=0.950, 95% CI: 0.864-0.989, P<0.01) was also better than RRI and PDU score, but slightly worse than RRI/PDU and RRI+PDU, with statistically difference only between RRI and RRI-RDU/10 ( P<0.05). Conclusions:The combination of RRI and PDU score could effectively predict AKI 3 in non-septic critically ill patients, especially in patients with AHF. The ratio of RRI to PDU score is recommended for clinical application because of its excellent predictive value for AKI and its practicability.