The Relationship Between IRRIV and RFR Under Pathologic Conditions (IRRIV-RFR)

The assessment of renal functional reserve (RFR) has been proposed for the risk stratification of patients undergoing potentially nephrotoxic procedures. The present pilot study is designed to explore the correlation between IRRIV and RFR under pathologic conditions.

Study Overview

• Status: Completed
• Conditions: Acute Kidney Injury

Detailed Description

Renal functional reserve (RFR) represents the capacity of the kidney to increase glomerular filtration rate (GFR) in response to certain physiological or pathological stimuli or conditions.

RFR is calculated as the difference between the measured maximum GFR achieved through a renal stress test and the baseline GFR measured in rest conditions. In clinical practice, the most common renal stress test is performed as a standardized protein loading test. Recently, in a pilot study, the investigators demonstrated a significant correlation between RFR and the intra-parenchymal renal resistive index variation (IRRIV) during an echo renal stress test in a cohort of healthy volunteers. IRRIV test has proven to be rapid, safe, bedside and easy to perform and it might represent a preliminary test in screening patients' RFR.The present pilot study is designed to explore the correlation between IRRIV and RFR under pathologic conditions.

• Study Type: Observational
• Enrollment (Actual): 31

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients scheduled for cardiac surgery with cardiopulmonary bypass (coronary artery bypass, valve replacements, combined or other operations)

Description

Inclusion Criteria:

• Estimated GFR (CKD-EPI) greater than or equal to 60 mL/min/1.73 m2
• Scheduled cardiac surgery with cardiopulmonary bypass (coronary artery bypass, valve replacements, combined or other operations).

Exclusion Criteria:

• Age less than 18 years old
• Pregnancy
• Ultrasound evidence of morphological kidney abnormalities and/or renal artery stenosis
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Contrast media in the 2 days before the tests.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

IRRIV and RFR; Enrolled patients will receive IRRIV test and RFR assessment. RFR will be evaluated through a protein loading test. (1.2 g of protein/Kg of body weight) performed with cooked beef. The RFR was then defined as the difference between the highest CrCl obtained after the protein load and the baseline CrCl measured on rest conditions. Concerning the IRRIV test, a weight of 10% of the patient's body weight is applied on the abdominal wall. RRIs is recorded in a middle interlobular artery, every minute for 10 minutes during the echo-renal stress test. The lowest RRI reached is taken as reference (stress RRI). The IRRIV is defined as the percentage difference between baseline RRI and stress RRI

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between IRRIV test and RFR in cardiac surgery patients	IRRIV test and RFR will be determined and a relationship will be assessed	Change from baseline to 60 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concordance between IRRIV test and RFR in cardiac surgery patients	Concordance between presence of RFR (i.e. a RFR≥15ml/min/1.73m2) and a positive/uncertain/negative IRRIV is evaluated.	Change from baseline to 60 minutes

Collaborators and Investigators

• Sponsor: Ospedale San Bortolo di Vicenza
• Investigators: Study Director: Claudio Ronco, Ospedale San Bortolo di Vicenza

Publications and helpful links

General Publications

• Samoni S, Nalesso F, Meola M, Villa G, De Cal M, De Rosa S, Petrucci I, Brendolan A, Rosner MH, Ronco C. Intra-Parenchymal Renal Resistive Index Variation (IRRIV) Describes Renal Functional Reserve (RFR): Pilot Study in Healthy Volunteers. Front Physiol. 2016 Jul 6;7:286. doi: 10.3389/fphys.2016.00286. eCollection 2016.

Helpful Links

• SSamoni ppt

Study record dates

Study Major Dates

• Study Start (ACTUAL): September 2, 2015
• Primary Completion (ACTUAL): November 10, 2015
• Study Completion (ACTUAL): January 13, 2016

Study Registration Dates

• First Submitted: November 26, 2018
• First Submitted That Met QC Criteria: November 26, 2018
• First Posted (ACTUAL): November 28, 2018

Study Record Updates

• Last Update Posted (ACTUAL): November 29, 2018
• Last Update Submitted That Met QC Criteria: November 27, 2018
• Last Verified: November 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Kidney Diseases; Urologic Diseases; Renal Insufficiency; Acute Kidney Injury
• Other Study ID Numbers: 35/14

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No