#2543 NEPHROFLOW FOR ESTIMATION OF VASCULAR ACCESS FLOW FOR HEMODIALYSIS: WHEN TO MEASURE?

Abstract

Abstract Background and Aims Current guidelines emphasize the need for surveillance of vascular access (VA) for hemodialysis (HD), especially arteriovenous fistulas (AVF). Detecting a reduction in VA flow is auseful tool to anticipate the complications of VA as thrombosis. The DMed NephroFlow(NIPRO®) system, based on ultrasound dilution (UD) methods, has been shown tobe comparable to the classic Transonic® measurement system for estimating VA flow and canbe applied for VA surveillance. Our objetctive is to determine if there are significant differences when performing flow measurements with NephroFlow® between the first hour and the second hour of the HD session, as well as between any of the three days in which the patient attends HD. Method For two consecutive weeks, patients with AVF or graft (gAVF) on HD in our unit underwent VA flow measurements using the NephroFlow® system at the first and second hour of HD, on the 3 days that they attended HD sessions. Interspersing the first hour with the second each week to avoid significant loss in HD quality. For the study, we proceeded according to the usual recommendations of stable flow at 250 ml/min, corresponding ultrafiltration rate, needles in the same vein, without change in dry weight, with the same nurse staff, and transferring all patients to conventional HD. Results Twenty-one patients have been included, 13 male and 8 female, mean age 68±12.3 years. The mean time on HD was 36±23 months. The type of VA was: 10 patients presented a radiocephalic AVF, 5 brachiocephalic AVF, 2 patients a brachiobasilic AVF, and 4 patients a gAVF. The estimated mean flow obtained by NephroFlow ® in the first hour of all sessions and in the second hour was 1056 ± 754 and 1130.16 ± 769 ml/min, respectively; intraclass correlation index was 0.737 and K-W Test H 0.349 (p≤0.05). The mean flow on the first day was 1129±794.5ml/min, ICC = 0.662; second day 1027.5±729ml/min, ICC = 0.812; third day 1121.5±±ml/min, ICC = 0.774. In all cases p<0.05. Conclusion No significant differences have been observed in the VA flow estimated with the NephroFlow® ultrasound dilution system, neither at measurement time (the first or the second hour of HD session) nor day of performance (first, second or third day of HD session of the week). NephroFlow® UD system may be a useful tool for VA surveillance and could be applied when is necessary.