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.

Objective:To investigate the clinical value of thromboelastogram in early diagnosis of deep vein thrombosis (DVT) in patients undergoing free flap surgery of lower extremity.Methods:A retrospective study was conducted to analyze the 192 patients undergoing surgical repair of soft tissue defects at lower extremity with free anterolateral femoral flap at Department of Orthopaedics, Tongji Hospital from January 2018 to June 2022. There were 117 males and 75 females, with an age of (45.6±12.7) years and an area of skin defects ranging from 5 cm × 3 cm to 18 cm × 9 cm. The patients were divided into 2 groups according to whether DVT occurred on the first day after surgery. In the DVT group of 22 patients, there were 14 males and 8 females, with an age of (47.7±14.3) years; in the DVT-free group of 170 patients, there were 103 males and 67 females, with an age of (45.3±12.5) years. The 2 groups were compared in terms of reaction time, coagulation time, maximum amplitude and coagulation angle in the thromboelastogram. Diagram of receiver operating characteristic (ROC) curves was used to evaluate the predictive value of thromboelastography in assessing the risk of DVT after surgery.Results:The 2 groups were comparable because there was no significant difference in the baseline information or operation time between them ( P>0.05). The reaction time [(5.21±0.85) min] and coagulation time [(1.12±0.30) min] in the DVT group were significantly shorter than those in the DVT-free group [(6.48±0.06) min and (1.60±0.03) min], and the maximum amplitude [(71.45±1.17) mm] and coagulation angle [69.54° (64.59°, 76.64°) ] in the DVT group were significantly larger than those in the DVT-free group [(66.63±0.40) mm and 64.92°(54.11°, 74.21°)] (all P<0.05). The optimal cut-off points in the ROC diagram were 5.46 min at reaction time, 1.52 min at coagulation time, 72.31 mm at maximum amplitude and 59.89° at coagulation angle. The sensitivity and specificity of detecting DVT on the first day after surgery were 80.7% and 71.6%, respectively, according to the combination of the best cut-off points in the ROC diagram and all the indexes in the thromboelastogram. Conclusion:Thromboelastogram is of a great value for the diagnosis of lower extremity DVT, and of a positive significance for the prevention of serious complications after surgery in patients undergoing free flap surgery of lower extremity.