Physiologic variability of vascular access blood flow for hemodialysis

Abstract

Aim: To assess the variability of blood flow (QVA) through a native arteriovenous fistula (AVF) in the long-term and to determine the QVA reduction at which an intervention is appropriate.

Patients and methods: The study was performed in a group of 34 chronic hemodialysis patients with no history of a AVF intervention. QVA was measured using the thermodilution method (Blood Thermodilution Monitor, Fresenius). Median follow-up was 41 months and the median number of QVA measurements in each patient was 15. The coefficient of variation (CV) of QVA was calculated for each patient.

Results: Mean QVA was 904 +/- 334 ml/min. The mean CV was 23.3 +/- 11.2%.

Conclusion: QVA may fluctuate during a long-term follow-up period. The detection of QVA decrease by 20-25% could be still within physiological limits. Based on the results we recommend to first repeat the measurement at a shorter interval and to refer the patient to a radiologist only when the decreasing trend is confirmed.