Stenosis Monitoring

Lynda K. Ball, RN, BSN, CNN

According to the NKF-KDOQI Guidelines, every dialysis facility should be monitoring vascular accesses for venous stenosis.  Early intervention can extend the life of an access, especially if stenosis can be identified before the access completely fails.  There are several methods of monitoring for venous stenosis they are summarized below.

MonitorFrequencyTimingWhat to look forAccess
Intra-Access Flow (preferred) Monthly During first 1.50 on dialysis x 3 separate measurements
  • Flow < 600 ml/min = fistulogram
  • Flow < 1000 ml/min that has decreased more than 25% over 4 months = fistulogram
Both
  • AVG
  • AVF
Static Venous Pressures Every two weeks Venous pressure at 0 ml/min blood pump speed after running the prescribed blood flow for one hour
  • Trend of increasing venous pressure readings = venography
  • Ratio of intra-access pressure to mean arterial pressure = venography
Both
  • AVG
  • AVF
Duplex Ultrasound As indicated Greater than 50% of normal vessel diameter Recirculation, elevated VPs, decreased blood flow, swollen extremity, increased arterial pre-pump pressures, and decrease KT/V Both
  • AVG
  • AVF
Urea Recirculation As needed At 30 minutes into dialysis, turning off ultrafiltration
  • >10% = angiography (fistulography)
  • >20%, check needle placement first, then reassess
AVF
Unexplained decreases in KT/V or URR Monthly labs;
Assessments - each treatment
  • Reviewing monthly lab work.
  • During pre- and post-dialysis assessments
  • Downward trending KT/V or URR
  • Edema of the access arm
  • Changes in thrill or bruit
  • Prolonged bleeding after needle removal - any combinations = venography
Both
  • AVG
  • AVF

National Kidney Foundation. KDOQI Clinical Practice Guidelines and Clinical Practice Recommendations for 2006 Updates: Hemodialysis Adequacy, Peritoneal Adequacy and Vascular Access. Am J Kidney Dis 48:S1-S322, 2006 (suppl 1), http://www.kidney.org/professionals/kdoqi/guidelines.cfm .

Page updated December 22, 2014