Sensing Savvy

A 75-year-old female patient with a central venous catheter underwent a Flow-QC test with a Transonic Hemodialysis Monitor. Her blood lines were in a normal line position. The pump setting on the hemodialysis machine was 290 mL/min. The Flow-QC test measured Delivered Blood Flow at 190 mL/min along with no recirculation.

“Very high reproducibility and negligible impact of flow (Qb) on vascular access flow (QVA) determination justifies the current ultrasound dilution status as a reference method in QVA evaluation.” Lopot et al¹

“Any access recirculation is abnormal. Recirculation … should have prompt investigation of its cause. … If access recirculation values exceed 20%, correct placement of needles should be confirmed before conducting further studies.” http://www.kidney.org/professional/KDOQI/guidelineñupHDñVA/index.htm

As the value of surveillance in managing vascular accesses is undergoing scrutiny, a critical review by distinguished leaders in the field including Drs. A Besarab, A Asif, P Roy-Chaudhury, LM Spergel and P Ravani responds to the skepticism about access surveillance.

“Adequate blood flow in peripheral hemodialysis fistulae and grafts is vital to the success of hemodialysis and to the survival of the patient. Reduction in flow ... presages failure of the access device itself. Access flow can therefore be considered a fundamental property of the access that should be monitored.” Depner TA, MD, UC Davis

“The Transonic Flow-QC Hemodialysis Monitor has benefited numerous dialysis-dependent patients by reducing and, in many cases, eliminating the agony of a clotted AV graft or fistula, thereby facilitating correction of access stenoses on an elective basis that prevents missed dialysis and the need for placing temporary catheters.”

Thomas Depner, MD, UC Davis

“The Transonic Flow-QC Hemodialysis Monitor has benefited numerous dialysis-dependent patients by reducing and, in many cases, eliminating the agony of a clotted AV graft or fistula, thereby facilitating correction of access stenoses on an elective basis that prevents missed dialyses and the need for placing temporary catheters.” Depner T, MD, UC Davis

“QA-based surveillance combining Doppler ultrasound and ultrasound dilution reduces the frequency of thrombosis, is cost effective, and improves thrombosis free and secondary patency in autologous AV.”Aragoncillo I et al, “Adding access blood flow surveillance reduces thrombosis and improves arteriovenous fistula patency: a randomized controlled trial,” J Vasc Access. 2017 Apr 20:0. (Transonic Reference # HD11190)

Transonic ultrasound dilution technology revolutionized comprehensive vascular access patency management by enabling routine surveillance to detect decreasing access flows that presage access thrombosis failure.^2-6 However, the value of vascular access surveillance continues to spark a spirited debate within the nephrology community with skeptics of surveillance challenging its value and proponents lauding its value.

Studies that attest to the value of vascular access surveillance coupled with early intervention, to reduce the thrombosis rate in both fistulas and grafts include the following:

Mary Christiensen moved to the senior citizen’s residence after her husband died. The move had been traumatic. Mary felt uprooted, having left behind friends and the home she and her husband had shared for 42 years. One constant remained from her old life. Three times a week she would be driven to a clinic for hemodialysis, as she had for the seven years when her kidneys failed. Even though the treatments drained her, she welcomed them because she would then feel better for a day or so.

Ultrasound indicator dilution is the current Gold Standard for measurement of vascular access recirculation and access flow;¹

• Ultrasound indicator dilution is the method of choice for monthly surveillance of vascular access grafts in adherence to NKF-K/DOQI guidelines
• Available evidence suggests that access flow measurements are the best tests currently available to screen for access dysfunction.
• Monthly surveillance is a cost-effective strategy.