Predictive value of renal venous Doppler waveform pattern for 28-day renal dysfunction in critically ill patients / 中华急诊医学杂志

ABSTRACT

Objective:This study aimed to explore the performance of renal resistive index (RRI), semiquantitative power Doppler ultrasound (PDU) score, and renal venous Doppler waveform (RVDW) pattern in predicting 28-day renal dysfunction in critically ill patients and establish nomogram model.Methods:This was a prospective, observational study. Critically ill patients admitted to the emergency intensive care unit (ICU) of Cangzhou Central Hospital from January 2018 to October 2022 were included. Patients underwent renal ultrasound examination to obtain RRI, PDU score and RVDW pattern within 24 h after ICU admission. The following clinical variables were collected during the renal ultrasound examination session, including heart rate, mean arterial pressure, type and dose of vasoactive drugs, oxygen therapy parameters, and average urine volume per hour derived from a period of 6 h prior to the ultrasound examination. The data on duration of AKI and mortality were recorded on the 28th day of follow-up. Patients were divided into 28-day normal renal function group and 28-day renal dysfunction group according to 28-day renal dysfunction. 28-days of renal dysfunction was defined as failure to achieve renal function recovery within 28 days of ICU admission. The difference of each index between the two groups was compared. Associated factors for 28-day renal dysfunction were determined by univariate and multivariate COX regression analyses. A nomogram was developed based on the independently factors associated with 28-day renal dysfunction. Survival receiver operator characteristic (ROC) curves were plotted to assess diagnostic performance in predicting 28-day renal dysfunction. Delong’s test was used to compare area under the curves (AUC) between each predictor.Results:187 patients were enrolled for the final analysis: 97 with no AKI, 48 with AKI stage 1, 24 with AKI stage 2, and 18 with AKI stage 3 upon enrollment. At 28-day follow up, 16 patients had renal dysfunction and 2 required continuous renal replacement therapy (CRRT). The multivariate COX regression showed that RVDW and SCr upon enrollment were the independent risk predictors. Nomogram based on RVDW and SCr upon enrollment showed the best performance in predicting 14-day renal dysfunction (AUC = 0.918, 95% CI:0.871-0.964, P<0.05), and the AUC was statistically significantly higher than single index (all P<0.05). Nomogram also showed the best performance in predicting 28-day renal dysfunction (AUC = 0.924, 95% CI:0.865-0.983, P<0.05), and the AUC was statistically significantly higher than single index (all P<0.05) except for SCr upon enrollment. The optimal cutoff for nomogram in predicting 28-day renal dysfunction was ≤89.5 (sensitivity, 81.2%; specificity, 90.6%; Youden index, 0.719). Kaplan-Meier analysis showed that the median duration of renal dysfunction in the groups with total nomogram score >85.9 and ≤85.9 was 0 and 22 days (HR=0.220, 95% CI:0.129-0.376, P<0.001). Conclusions:SCr and RVDW pattern within 24 h from ICU admission were independent factors associated with 28-day renal dysfunction in critically ill patients. The value of the nomogram model based on these two factors in predicting 28-day renal dysfunction is superior to each single intrarenal Doppler spectrum indicator and clinical indicator.