CANNT Journal. 27(3):13–19, JUL 2017
Issn Print: 1483-698X
Publication Date: 2017/07/01
Examining the effect of blood flow rate on hemodialysis urea clearance
Keira St. George;Lynda Whitlum;John Duncan;
Abstract
The National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF KDOQI) 2015guidelines identify urea clearance as the primary measure of hemodialysis adequacy, and note that a blood flow rate (Qb) of less than 300 mL/min provides insufficient clearance. There are no guidelines as to the optimal blood flow rate greater than 300 mL/min. Scant research exists on how clearance differs according to blood flow rate. Some suggest that a higher blood flow rate could negatively impact the health of arteriovenous fistulae (AVF). The authors hypothesized that clearance would meet or exceed KDOQI minimum guidelines of Kt/V 1.2 and URR (urea reduction ratio) 65%, whether dialyzing at Qb 320 mL/min or Qb 380 mL/min. Using a randomized, crossover design, data were collected from 24 patients with AVF dialyzing at a single centre over four weeks. Results showed that both Qb 320 mL/min and Qb 380 mL/min have Kt/V and URR averages above the minimally adequate doses, although the latter had an 11% higher Kt/V. This study establishes the need and importance of larger and longer studies examining clearance, Qb, and fistula health.Key words: dialysis, blood flow, clearance rate, dialysis adequacy, dialysis clearance, flow adequacy, flow rate, hemodialysis, Qb
