title: Two-operator glucose infusion test (GIT2) for vascular access recirculation measurement during hemodialysis.
abstract: Vascular access recirculation rate (AR) monitoring is fundamental to guarantee treatment adequacy and to detect access failure early. We have evaluated the GIT2 test to measure AR unaffected by cardio-pulmonary recirculation (CPR), based on a short glucose infusion in place of the bolus and on a two-operator sampling, differently from the classical glucose infusion test (GIT). The GIT2 test is based on four steps: 1) basal (B) glucose arterial sample; 2) 10% glucose infusion for 1 min, by infusion pump at 600 ml/hr; (or 20% at 300 ml/hr); 3) simultaneous sampling at arterial (A) and venous (V) ports, after 35-40 sec from starting the infusion, taking care to avoid blood pump stop during the test; 4) AR=100*((A-B)/(V-B)). In vitro tests by dialysis on a 40 L tank containing a urea solution, with AR volumetrically simulated at 0, 5, 10, 20%, and in vivo comparison of GIT, GIT2 with stop-flow (SF) urea method. Our results have shown in vitro an almost perfect correspondence of SF urea method and a better reliability of GIT2 than GIT. The methylene-blue test has shown that a single color bolus in V reaches the A port after variable time, depending on blood flow and AR, while the continuous infusion determines a steady gradient after about 30". In vivo tests (n=24) show good correspondence between GIT2 (4.37 +/- 3.36) and SF (4.51 +/- 3.62), while GIT data (1.01 +/- 0.51) are significantly underestimated. In conclusion, our preliminary results have evidenced a good reliability of the new test, the continuous infusion causing a steady gradient in V and A that more precisely reflects the AR rate.
authors.affiliation: Nephrology Unit, ASL BI, Biella, Italy. gmbostic@alice.it
authors.forename: Gian Mario
authors.initials: GM
authors.lastname: Bosticardo
authors.forename: Veronica
authors.initials: V
authors.lastname: Morellini
authors.forename: Enrico
authors.initials: E
authors.lastname: Schillaci
authors.forename: Marco
authors.initials: M
authors.lastname: Battisti
authors.forename: Massimo
authors.initials: M
authors.lastname: Norza
authors.forename: Paolo
authors.initials: P
authors.lastname: Detoma
authors.forename: Giacomo
authors.initials: G
authors.lastname: Forneris
authors.forename: Oliviero
authors.initials: O
authors.lastname: Filiberti
authors.forename: Pietro
authors.initials: P
authors.lastname: Bajardi
mesh_terms: D001166:Arteriovenous Shunt, Surgical; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism*; D005947:Glucose / Q000008:administration & dosage; D007260:Infusion Pumps; D008751:Methylene Blue / Q000008:administration & dosage; D011237:Predictive Value of Tests; D006435:Renal Dialysis; D015203:Reproducibility of Results; D013997:Time Factors; D014508:Urea / Q000008:administration & dosage
chemical_list: D001786:Blood Glucose; D014508:Urea; D005947:Glucose; D008751:Methylene Blue