Relation between Renal Resistive Index and Serum Albumin in Nephrotic Syndrome

BACKGROUND Renal resistive index (RRI) is a non-invasive marker of renal function, which can be measured by renal USG Doppler. High RI indicates poor prognosis, which has been associated with conditions such as proteinuria, hypertension, chronic kidney disease and renal failure. As nephrotic syndrome is characterised by significant proteinuria and hypoalbuminemia, which may progress to renal failure, it is important to see the correlation of RRI with serum albumin level. The purpose of this study was to assess the relation between renal resistive index and serum albumin in nephrotic syndrome. METHODS USG renal Doppler was done for all the children with nephrotic syndrome and RRI was calculated as [(peak - systolic velocity − end - diastolic velocity) / peak - systolic velocity]. Blood investigations were also done, from which serum albumin values were obtained. RRI was compared with mean serum albumin level. Statistical analysis of data was performed using the computer programme, Statistical Package for Social Sciences (SPSS for windows, version 21.01, Chicago, SPSS Inc.) and Microsoft excel 2010. Results on continuous measurement were presented as mean ± standard deviation and compared using Analysis of Variance (ANOVA). RESULTS The mean serum albumin in the children with nephrotic syndrome in our study was 1.82 ± 0.32 gm / dl. The mean RI value was 0.66 ± 0.14 SD, 0.64 ± 0.15 SD and 0.66 ± 0.12 SD as well as 0.63 ± 0.12 SD, 0.67 ± 0.16 SD and 0.71 ± 0.13 SD on the right and left kidney respectively for each of upper, middle, and lower pole. P value of left kidney and right kidney was 0.0057 and 0.6409 respectively. CONCLUSIONS Lower the mean serum albumin level, higher the range of RRI. KEY WORDS Serum Albumin, Renal Resistive Index, Nephrotic Syndrome, USG Renal Doppler

MO437RENAL RESISTIVE INDEX IS INDEPENDENTLY ASSOCIATED WITH THE RENAL BLOOD FLOW IN HYPERTENSIVE PATIENTS

Background and Aims The Renal Resistive Index (RRI) measured in intrarenal arteries is considered a marker of cardiovascular damage, and its value can express the amount of renal perfusion. However, some experimental investigations don’t confirm this association. Moreover, in recent works, End Diastolic Velocity (EDV) was used as a better than RRI marker of kidney damage. The study aimed to investigate relations between different ultrasound Renal Doppler parameters (RRI, acceleration (ACC), acceleration time (ACT), and EDV) with the Renal Blood Flow (RBF) estimated in contrast-enhanced computed tomography (CE-MDCT). Method In 25 patients (14F, 11M; age 58.9 ±19.0; eGFR 56,9 ±27.4 mL/min/1.73m2) with hypertension and suspected renal artery stenosis, ultrasound Color Doppler examination of intrarenal segmental arteries (GE Logiq P6) was performed. Then CE-MDCT (GE Discovery 750 HD) of renal arteries with RBF assessment was completed. Renal Doppler parameters (RRI, ACC, ACT, and EDV) and RBF were evaluated for each kidney separately. Finally, 31 kidneys without a narrowing of supplying arteries were considered for statistics. Results Mean values of intrarenal Doppler parameters were calculated: RRI = 0.699 ±0.113; ACC = 7.41 ±2.75 [m/s2]; ACT = 35.8 ±8.4 [ms]; EDV = 13.68 ±8.41 [cm/s]. CE-MDCT RBF = 218.04 ±71.92 [ml/s/100g]. Only RRI and EDV correlated significantly with RBF (r = -0.544; p=0.002 and r=0.428; p=0.018, respectively). The retrograde multivariable regression analysis included all investigated ultrasound renal Doppler parameters showed an independent association only between RRI and RBF (b = -0.544; R2 = 0.27, p < 0.002). Conclusion Only Renal Resistive Index measured in intrarenal segmental arteries is independently related to the Renal Blood Flow from investigated ultrasound renal Doppler parameters. Although End Diastolic Velocity is positively correlated with RBF, this association is not superior to Renal Resistive Index.

Transabdominal Renal Doppler Ultrasound in Healthy Adult Holstein-Friesian Cows: A Pilot Study

There is a notable lack of reference values for the renal resistive indices in the bovine kidney. Ultrasound (US) Doppler evaluation of these indices is a powerful, non-invasive technique for assessing, monitoring and diagnosing renal diseases in humans and other animals (e.g., small animals and horses). The aims of the present study were to establish a protocol for renal Doppler US in adult healthy Holstein-Friesian cows and to provide reference values for the renal resistive index (RI) and pulsatility index (PI). In cattle, the right kidney is always visible through a right abdominal window. Nevertheless, the left kidney is rarely accessible by transabdominal ultrasound. Doppler evaluation of the kidneys via a transabdominal approach is possible when accessible, but measurements can only be made in the larger vessels at the renal hilum. Normal RI and PI values were respectively 0.49 ± 0.07 and 0.70 ± 0.15 for the right kidney and 0.53 ± 0.05 and 0.79 ± 0.11 for the left kidney. We suggest an upper cut-off value for the RI of 0.63 and for the PI of 1.00 in healthy Holstein-Friesian cows. This is the first report describing normal values for the renal RI and PI in cattle that may be useful in future studies for characterizing different bovine pathologies that affect the renal parenchyma.

Non-invasive evaluation of obstruction after ureteroscopic stone removal: Role of renal resistive index assessment

Objectives: The aim of this study is to evaluate prediction of postoperative ureteral obstruction needing ureteral stent insertion by evaluating the resistive index (RI) values and the grade of hydronephrosis. Material and Methods: A total of 66 adult patients undergoing stentless endoscopic ureteral stone treatment (URS) between January 2018 and January 2019 were included in this prospective study. Preoperative patient and stone characteristics were noted. All patients were evaluated with renal Doppler ultrasonography study to assess degree of hydronephrosis and RI values. A renal Doppler ultrasonography was repeated at postoperative 1st, 3rd and 7th days. Changes in both RI and hydronephrosis levels before and after the procedures were noted. On the postoperative 7th day, patients were divided into two groups including obstructive and non-obstructive cases according to RI values assessed where a RI value of 0.7 was accepted as the cut-off for obstruction. The preoperative and perioperative characteristics of both groups were evaluated in a comparative manner. Results: The mean patient age was 43.6 ± 1.72 years. Significant improvements were noted in RI and grade of hydronephrosis after the operation. The grade of hydronephrosis and RI values were found to improve more significantly on postoperative 3rd day when compared to the postoperative 7th day (p < 0.01 and p < 0.01). A significant correlation was detected between the grade of hydronephrosis (>grade 2) and obstructive RI values (> 0.7) in each postoperative visits (p: 0.001). RI values (> 0.7) at postoperative seventh days were correlated with larger mean stone size, increased ureteral wall thickness, increased diameter of the ureter proximal to the stone, and longer duration of the operation. Preoperative high-grade hydronephrosis indicated obstructive RI values at postoperative seventh day (p = 0.001) Conclusion: Changes in RI values on Doppler sonography and the grade of hydronephrosis may be a guiding parameter in assessing postoperative ureteral obstruction.