There is general consensus that the AV fistula is the preferred vascular access for end-stage renal disease patients undergoing hemodialysis. The AV fistula has been associated with reduced hospitalizations for AV access failure, fewer missed treatments, fewer invasive surgical procedures, fewer infections and reduced costs compared with vascular access grafts or catheters. On the Fistula First/Catheter Last website, the arteriovenous fistula is called the “Lifeline for a Lifetime.”
You can measure vascular access flow with your HD02/HD03 Hemodialysis Monitor on any manufacturer’s blood tubing set by using a Fresenius Medical Care TwisterTM CombiSet bloodline or the stand alone TwisterTM accessory. The TwisterTM enables reversal of the blood lines without manually disconnected them to measure vascular access flow via the Krivitski Method®. The arterial and venous Flow/dilution Sensors are clamped between the TwisterTM and the red and blue caps on the lines that go to the patient’s access. All HD03 and all HD02 software versions 2.0.0 or higher do not require any repositioning of the Flow/dilution Sensors. Simply use the TwisterTM to reverse the bloodlines and take your vascular access measurement.
Although extensively documented in the literature, the AV access is often overlooked as a source of cardiac dysfunction. By bypassing the customary arteriole/capillary beds and establishing a direct high flow connection between the arterial and venous systems, an AV access creates a drop in peripheral arterial resistance that significantly affects blood flow. In order to maintain blood pressure and improve cardiac output, the body compensates for this precipitous drop in resistance by increasing heart rate and stroke volume. This phenomena was first observed in World War II soldiers with trauma-induced arteriovenous fistulas. Iwashima et al reported an 15% increase in cardiac output by the seventh day after arteriovenous fistula creation1. This increased cardiac workload can lead to an increase in size of the left ventricle (left ventricular hypertrophy).
Transonic ’s gold standard Hemodialysis Monitor is used to trend vascular access flow to assess vascular access patency. Unlike other technologies that can only identify outflow stenoses in AV accesses, HD03 Monitor surveillance can detect a stenosis wherever it occurs within the vascular access circuit: inflow, outflow or between the needles in both fistulas or grafts.
The most common access in children remains a central venous catheter (CVC) even though an arteriovenous fistula meets the criteria of delivering a flow rate needed for the dialysis prescription, has a long use life and a low rate of complications. Nationally, only 12.3% of pediatric patients have an AVF and and 8.5% have an AVG. Chand et al reported that, from his experience in northern Ohio where AVF rates in pediatric patients are more than 80%, higher AVF rates can be established through a multi-disciplinary team approach that involves pediatric nephrologists, experienced hemodialysis nurses, vascular surgeons, interventional radiologists and recreational therapist/child life specialists.1
The success of the Centers for Medicare and Medicaid Services (CMS) Fistula First Break-through Initiative has transformed a hemodialysis access in the United States from a “graft-oriented culture” to a “fistula-oriented culture” in less than 10 years. When the Fistula First Initiative took off in 2005, The United States lagged far behind their European counterparts in utilizing a fistula as a vascular access of choice for appropriate hemodialysis patients. An arteriovenous fistula (AVF) is the optimal vascular access for hemodialysis because it is associated with longer survival, fewer infections, lower hospitalization rates, and reduced costs. Now more than 60% of American hemodialysis patients have AV fistulas. The Fistula First goal is to reach 68%.
Transonic ’s Gold Standard Hemodialysis optimizes dialysis adequacy by:
- Identifying a Discrepancy Between Pump Setting & Delivered Blood Flow as a result of:
- Effects of negative pump pressure effects;
- Condition of access;
- Needle size & placement;
- Kinked or occluded tubing;
- Calibration of the dialysis machine;
- Change in type of dialysis tubing,
- Calibration of Flow/dilution Sensors.
The value of vascular access surveillance has been widely debated over the past decade. Some studies attest to its usefulness for identifying stenoses. Others question its value. Although all vascular access clinical guidelines recommend monitoring and surveillance protocols to prevent vascular access thrombosis, randomized clinical trials (RCT) have failed to consistently demonstrate the benefits of flow-based surveillance. Thus, the controversy over the value of surveillance continues.
Vascular Access Flow Surveillance is a medical imperative. Surveillance prolongs life, restores health, reduces pain and suffering in End Stage Renal Disease patients. Ultrasound transit-time indicator dilution flow technology is used to perform surveillance of a patients’ vascular access to prevent or delay the formation of a stenosis in the access. A stenosis can lead to a thrombosis and, if not attended to, ultimately abandonment of the access. Reducing such complications minimizes hemodialysis patient morbidity and mortality. One study demonstrated that vascular access blood flow monitoring decreased fistula thrombosis rate by at least 50%, while reducing access related costs by 48.5%.1
The hemodialysis patient’s vascular access is his or her lifeline. Successful hemodialysis depends on the health of the access. When an access fails, serious complications occur. Consequently, the vascular access has often been called the Achilles heel of hemodialysis.