THE RELATIONSHIP OF RECIRCULATION TO ACCESS BLOOD-FLOW

The relationship between vascular access recirculation and access bloo d flow has been obscured by measurement techniques that overestimate r ecirculation, We measured brachial artery blood flow (a surrogate for access blood flow) using Doppler ultrasound and access recirculation u sing a two-needle slow/stop flow method and the standard peripheral ve in method in 77 chronic hemodialysis patients, These patients had 25 n ative arteriovenous fistulae and 52 polytetrafluoroethylene grafts. Ac cess recirculation by the slow/stop flow method was uniformly absent i n these patients unless their access blood flow rate was less than the dialyzer blood flow rate, The peripheral vein method averaged 10.7% i n these patients; many values were considerably higher, We conclude th at access recirculation is a function of access blood flow and does no t occur (in the absence of or reversed needle cannulation) unless acce ss blood flow is markedly impaired. (C) 1997 by the National Kidney Fo undation, Inc.