External Validation of IRRIV Test Relationship With Renal Functional Reserve (IRRIV-RFR)

Ospedale San Bortolo di Vicenza

Status: Completed

Conditions: Acute Kidney Injury

Study type: Observational

Funder types: Other

Identifiers

NCT03756402

0103/15

Details and patient eligibility

About

The assessment of renal functional reserve (RFR) has been proposed for the risk stratification of patients undergoing potentially nephrotoxic procedures. The investigators hypothesized that there is a correlation between IRRIV and RFR under normal conditions. For this purpose, externally validation of IRRIV test is performed in a validation cohort of healthy subjects.

Full description

Normal subjects display a significant capacity to increase in baseline GFR under physiological needs (e.g. pregnancy) or pathological states (e.g. solitary kidney). This capacity is known as renal functional reserve (RFR), and it 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. 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. For this purpose, externally validation of IRRIV test is performed in a validation cohort of healthy subjects.

Enrollment: 47 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion criteria were:

• Age more than 18 years old;
• Baseline estimated GFR, calculated using the chronic kidney disease epidemiology collaboration (CKD-EPI) equation, greater than or equal to 60 ml/min/1.73 m2.

Exclusion criteria were:

• Age less than 18 years old;
• Comorbidities potentially affecting renal function (i.e. arterial hypertension, diabetes, vasculopathy, etc.;
• Chronic administration of drugs able to modify renal blood flow and/or GFR (angiotensin converting enzyme-inhibitors (ACEI), angiotensin receptor blockers (ARB), calcium channel blockers, loop diuretics etc.);
• Pregnancy;
• Ultrasound evidence of morphological kidney abnormalities and/or renal artery stenosis;
• Nonsteroidal anti-inflammatory drugs (NSAIDs) or contrast media in the 2 days before the tests.

Trial design

47 participants in 1 patient group

Healthy Subjects

Description:

All subjects underwent protein loading test and IRRIV test on the same day. The renal resistive index (RRI) measurements were performed by one trained sonographer using a multi-frequency convex probe through a manual RRI calculations. The RRIs were measured on three interlobular arteries (superior, middle and inferior) in each kidney, and expressed as a mean value. RFR was measured using an oral protein loading test and was then defined as the difference between the highest CrCl obtained after the protein load and the baseline CrCl measured on rest conditions. Urinary creatinine and sCr were measured by the enzymatic method (IL testTM Instrumentation(R), Laboratory SpA, Milano, Italy) and by ILab650 (Instrumentation Laboratory, Werfen Group, Barcelona, Spain).