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.

The Role of Ultrasound in the 2019 K-DOQI Vascular Access Guidelines

“…For accurate blood flow measurements, it is important to measure blood flow middialysis sessions or just before dialysis starts. Measuring blood flow immediately after dialysis is not recommended [24]. If borderline stenosis is identified without flow reduction during surveillance, we may consider angioplasty before the blood flow decreases.…”

Arteriovenous Hemodialysis Access Stenosis Diagnosed by Duplex Doppler Ultrasonography: A Review

“…Higher values could be associated with heart failure or hand ischemia [ 31 ]. Importantly, Qa physiologically fluctuates with blood pressure and hydration levels—as does the cardiac output [ 32 ].…”

Vascular access ultrasonography: The risk of simplification

“…A flow volume decrease by >25% represent an additional warning as also mentioned by Manov et al, 2 but a natural flow volume variation within 23% was also described. 6…”