Renal Resistive Index Measurement by Transesophageal Echocardiography: Comparison With Translumbar Ultrasonography and Relation to Acute Kidney Injury

• Published in: Journal of cardiothoracic and vascular anesthesia Vol. 29; no. 4; pp. 875 - 880
• Main Authors: Kararmaz, Alper, MD, Kemal Arslantas, Mustafa, MD, Cinel, Ismail, MD, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2015
• Subjects: acute kidney injury; Acute Kidney Injury - diagnostic imaging; Acute Kidney Injury - etiology; Adult; Aged; Anesthesia & Perioperative Care; cardiac surgery; Cardiac Surgical Procedures - adverse effects; Critical Care; Doppler; Echocardiography, Transesophageal - methods; Female; Humans; Kidney - diagnostic imaging; Kidney - physiology; Lumbosacral Region - diagnostic imaging; Male; Middle Aged; Monitoring, Intraoperative - methods; Postoperative Complications - diagnostic imaging; Postoperative Complications - etiology; Prospective Studies; renal resistive index; transesophageal echocardiography; cardiac surgery; transesophageal echocardiography; acute kidney injury; renal resistive index; Doppler
• ISSN: 1053-0770; 1532-8422
• DOI: 10.1053/j.jvca.2014.11.003

Objectives The aim of this study was to evaluate the relationship between transesophageal ultrasonography-derived renal resistive index values (RRITEE ) and a standard translumbar renal ultrasound-derived RRI (RRITLUSG ). The effectiveness of each method to predict acute kidney injury (AKI) after cardiac surgery also was compared. Design A prospective observational study. Setting A teaching university hospital. Participants Sixty patients undergoing cardiac surgery. Interventions First, RRI was measured with both methods after anesthesia induction. Second, another measurement was performed with TEE after cardiopulmonary bypass and immediately following the surgery with translumbar ultrasound. To test the correlation between the 2 methods and to plot a Bland-Altman graph, preoperative RRI values measured by both techniques were used. Receiver operating characteristic curves also were plotted to compare the diagnostic values of RRI measured intraoperatively by TEE after cardiopulmonary bypass and by RRITLUSG after surgery. Measurements and Main Results There was a statistically significant correlation between the 2 RRI measurement approaches (r = 0.86, p<0.0001). The Bland-Altman plot indicated good agreement between the methods. The area under the curve (AUC) of RRITEE in predicting AKI was 0.82 (95% confidence interval [CI] = 0.64-0.9, p = 0.001), and the AUC of RRITLUSG after surgery was 0.85 (95% CI = 0.7-0.98, p<0.0001). In predicting AKI, an uncertainty zone for RRITEE values between 0.68 and 0.71 was computed by the gray-zone approach. Conclusions RRITEE showed clinically acceptable agreement with RRITLUSG . Indeed, RRI measured intraoperatively with TEE was comparable to RRITLUSG in terms of detecting postoperative AKI.