Sensing Savvy

Almost two million Americans suffer heart attacks and strokes each year. Heart disease and strokes account for about 30% of all deaths in the United States and are the first and fourth leading causes of death, respectively. But the good news is that the major risk factors for heart disease and stroke—high blood pressure, cholesterol, smoking, and obesity—can be prevented and controlled.

Over the past decade the health of Americans has improved in some areas: Life expectancy at birth has increased; rates of death from coronary heart disease and stroke have decreased. Nonetheless, public health challenges remain, and significant health disparities persist.

A serious error in the 2019 proposed National Kidney Foundation’s (NKF) Kidney Disease Outcomes Quality Initiative (KDOQI) is their grouping of all methods of vascular access surveillance as comparable. They are not! For instance, venous pressure measurements (Vasc Alert), can identify an outflow vascular access stenosis but cannot detect an inflow stenosis. In contrast, Transonic’s indicator dilution measurements can identify inflow and outflow stenoses as well as stenoses between the needles. This is significant because Asif et al, reported in his 2005 study “Inflow stenosis in arteriovenous fistulas and grafts: a multicenter, prospective study,” that 35% of vascular accesses sent for intervention do have inflow stenosis.¹

The 2019 proposed National Kidney Foundation’s (NKF) Kidney Disease Outcomes Quality Initiative (KDOQI) recommends a regular physical examination by a knowledgeable and experienced health practitioner to detect flow dysfunction. The proposed Guidelines cite five references to support their position.^1-5 Asif’s 2005 reference “Accuracy of physical examination in the detection of arteriovenous fistula stenosis” from the Miller School of Medicine at the University of Miami was referenced several times. Two other studies^3-4 also originated at that same institution. All four studies^1-4 cited the use of interventionalists, interventionalist fellows, or physicians trained in vascular access physical examinations to monitor for and detect AV-access flow dysfunction.

The value of vascular access surveillance has been widely debated over the past decade. Many studies attest to its usefulness for identifying stenoses. A few question its value. 

A 2015 randomized controlled trial (RCT) by Aragoncillo published in Journal of Vascular Surgery underscores the value of regular surveillance of hemodialysis patients.

The proposed 2019 Kidney Disease Outcomes Quality Initiative (KDOQI) Guidelines are now open for review with comments accepted through June 7, 2019. Transonic hopes hemodialysis stakeholders who have pre-registered to review the proposed Guidelines will submit their comments by the June 7th deadline.

A vascular access is required in order to have hemodialysis. The three most common types of vascular access are: an arteriovenous fistula (AVF) created by joining a vein and an artery, usually in the arm; an arteriovenous graft (AVG) formed by connecting an artery to a vein with a tube, or a central venous catheter (CVC). Optimally, a fistula or graft will be surgically created several months before dialysis starts, in order to ensure it is ready when it is needed. 

Dr. Nikolai Krivitski, hemodialysis pioneer, responds to the debate about vascular access surveillance that recently appeared in NDT in the article “Vascular Access Surveillance in Mature Fistulas: Is It Worthwhile?” Read his feedback to learn more about the history behind the publications and how some basic errors in scientific conclusions may impact your patient care.

A Central Venous Catheter (CVC) is a soft flexible tube that is placed into a large vein, usually in the chest. It has two openings or ports. During hemodialysis, the ports are connected to the hemodialysis machine; one to take blood from your body to be cleaned, and the other to return blood cleaned of its impurities back to the body. A CVC is often used while a patient is awaiting surgery to have an arteriovenous fistula or graft placed to be used as a permanent vascular access. Although not optimal, a CVC can also be used as a permanent vascular access.

When an access suddenly clots or thromboses, all stakeholders are confronted with a crisis that must be immediately resolved.

Needless to say, the end-stage renal disease (ESRD) patient has the most at stake and can suffer the most. He or she must cope with: