Sara Samoni1,2, Gianluca Villa3, Silvia De Rosa4, Mauro Neri5, Lorenzo Tofani6, Faeq Husain-Syed7, Massimo De Cal5, Federico Nalesso8, Mario Meola9, Claudio Ronco5,10. 1. Department of Nephrology, Dialysis and Transplantation, International Renal Research Institute Vicenza (IRRIV), San Bortolo Hospital, Vicenza, Italy. sarasamoni1@gmail.com. 2. Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy. sarasamoni1@gmail.com. 3. Department of Anesthesia and Intensive Care, Section of Oncological Anesthesia and Intensive Care, Azienda Ospedaliero Universitaria Careggi, Florence, Italy. 4. Department of Anaesthesia and Intensive Care, San Bortolo Hospital, Vicenza, Italy. 5. Department of Nephrology, Dialysis and Transplantation, International Renal Research Institute Vicenza (IRRIV), San Bortolo Hospital, Vicenza, Italy. 6. Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy. 7. Department of Internal Medicine II, Division of Nephrology, Pulmonology and Critical Care Medicine, University Hospital Giessen and Marburg, Giessen, Germany. 8. Department of Medicine, UOC Nefrologia 2, Azienda Ospedaliera, University of Padua, Padua, Italy. 9. Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy. 10. Department of Medicine, University of Padua, Padua, Italy.
Abstract
BACKGROUND: Renal functional reserve can be used as a clinical tool for risk stratification of patients undergoing potentially nephrotoxic procedures. Ultrasound assessment of intra-parenchymal renal resistive index variation-IRRIV test-has been recently proposed as a safe, reproducible, inexpensive and easy to perform technique to identify the presence of renal functional reserve. The present study has been designed to externally validate the IRRIV test in a validation cohort of healthy subjects. METHODS: We examined data from a group of 47 healthy subjects undergoing protein loading and IRRIV testing. The correlation between IRRIV and renal functional reserve was tested using Pearson correlation analysis. Concordance between presence of renal functional reserve (i.e. a value of renal functional reserve ≥ 15 ml/min/1.73 m2) and IRRIV was evaluated using logistic regression analysis. RESULTS: We found a significant correlation between IRRIV and renal functional reserve (Pearson correlation coefficient = 0.83 [95% confidence interval (CI) 0.71-0.90; p < 0.01]). Concordance between the presence of renal functional reserve and the IRRIV test was described in 45 (95.7%) subjects. In particular, a negative IRRIV test correctly predicted the absence of renal functional reserve in 5 subjects, while a positive IRRIV test correctly predicted the presence of renal functional reserve in 40 subjects. Only two subjects were incorrectly classified by the IRRIV test. IRRIV predicts renal functional reserve with a ROC-AUC of 0.86 [CI 95% 0.68-1]. CONCLUSIONS: The IRRIV test is an ultrasound technique that significantly predicts the presence and the degree of renal functional reserve in healthy subjects.
BACKGROUND: Renal functional reserve can be used as a clinical tool for risk stratification of patients undergoing potentially nephrotoxic procedures. Ultrasound assessment of intra-parenchymal renal resistive index variation-IRRIV test-has been recently proposed as a safe, reproducible, inexpensive and easy to perform technique to identify the presence of renal functional reserve. The present study has been designed to externally validate the IRRIV test in a validation cohort of healthy subjects. METHODS: We examined data from a group of 47 healthy subjects undergoing protein loading and IRRIV testing. The correlation between IRRIV and renal functional reserve was tested using Pearson correlation analysis. Concordance between presence of renal functional reserve (i.e. a value of renal functional reserve ≥ 15 ml/min/1.73 m2) and IRRIV was evaluated using logistic regression analysis. RESULTS: We found a significant correlation between IRRIV and renal functional reserve (Pearson correlation coefficient = 0.83 [95% confidence interval (CI) 0.71-0.90; p < 0.01]). Concordance between the presence of renal functional reserve and the IRRIV test was described in 45 (95.7%) subjects. In particular, a negative IRRIV test correctly predicted the absence of renal functional reserve in 5 subjects, while a positive IRRIV test correctly predicted the presence of renal functional reserve in 40 subjects. Only two subjects were incorrectly classified by the IRRIV test. IRRIV predicts renal functional reserve with a ROC-AUC of 0.86 [CI 95% 0.68-1]. CONCLUSIONS: The IRRIV test is an ultrasound technique that significantly predicts the presence and the degree of renal functional reserve in healthy subjects.
Authors: Andrew S Levey; Lesley A Stevens; Christopher H Schmid; Yaping Lucy Zhang; Alejandro F Castro; Harold I Feldman; John W Kusek; Paul Eggers; Frederick Van Lente; Tom Greene; Josef Coresh Journal: Ann Intern Med Date: 2009-05-05 Impact factor: 25.391