GIT (Glucose Infusion Test): polycentric evaluation of a new test for vascular access recirculation

Area of Science:

• Nephrology
• Vascular Access
• Dialysis Technology

Background:

• Vascular access recirculation (AR) is an often-overlooked cause of inadequate dialysis dose.
• Accurate detection of AR is crucial for optimizing hemodialysis treatment.
• The traditional Urea-test (UT) has limitations in sensitivity and reproducibility.

Purpose of the Study:

• To evaluate the Glucose Infusion Test (GIT) as a novel method for detecting and quantifying AR.
• To compare the performance of GIT against the established Urea-test (UT).
• To assess the prevalence of AR in different types of vascular access.

Main Methods:

• A polycentric evaluation involving 623 patients across eleven dialysis centers.
• GIT protocol involves arterial blood withdrawal, glucose injection, and subsequent arterial withdrawal for glucose measurement.
• Comparison of GIT with UT in 189 paired tests and reproducibility assessment in 28 paired tests.

Main Results:

• GIT screening identified AR in 11% of patients, predominantly in central venous catheters (CVCs) (54%) compared to arteriovenous fistulas (AVFs) (7%).
• GIT demonstrated high sensitivity and specificity when compared to UT, with results matching in 79% of paired tests.
• GIT exhibited superior reproducibility over UT, with a lower coefficient of variation (17% vs. 33%).

Conclusions:

• The Glucose Infusion Test (GIT) is a simple, immediate, and accurate method for detecting and quantifying vascular access recirculation.
• GIT confirmed a high prevalence of moderate AR in CVCs, highlighting a significant clinical issue.
• GIT offers improved accuracy, sensitivity, and reproducibility compared to the Urea-test for assessing AR in hemodialysis patients.