Education in vascular access.

The successful creation and use of an arteriovenous vascular access (VA) requires a coordinated, educated multidisciplinary team to ensure an optimal VA for each patient. Patient education programs on VA are associated with increased arteriovenous VA use at dialysis initiation. Education should be tailored to patient goals and preferences with the understanding that experiential education from patient to patient is far more influential than that provided by the healthcare professional. VA education for the nephrologist should focus on addressing the systematic and patient-level barriers in achieving a functional VA, with specific components relating to VA creation, maturation, and cannulation that consider patient goals and preferences. A deficit in nursing skills in the area of assessment and cannulation can have devastating consequences for hemodialysis patients. Delivery of an integrated education program increases nurses' knowledge of VA and development of simulation programs or constructs to assist in cannulation of the VA will greatly facilitate the much needed skill transfer. Adequate VA surgical training and experience are critical to the creation and outcomes of VA. Simulations can benefit nephrologists, dialysis nurses surgeons, and interventionalists though aiding in surgical creation, understanding of the physiology and anatomy of a dysfunctional VA, and practicing cannulation techniques. All future educational initiatives must emphasize the importance of multidisciplinary care to attain successful VA outcomes.

Arteriovenous fistulas for hemodialysis: application of high-frequency US to assess vein wall morphology for cannulation readiness.

PURPOSE: To determine whether venous wall thickness and hoop (circumferential) stress, as determined with high-frequency ultrasonography (US), can predict cannulation readiness in arteriovenous fistulas (AVFs). MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this prospective study. To determine the US appearance of the venous wall, an AVF specimen was excised and scanned in a bath of degassed lactated Ringer solution with a 55-MHz probe. The appearance of the wall at high-frequency US was correlated with histologic findings. High-frequency (40-55-MHz) US was used to image the near-field AVF venous wall of 14 men (mean age, 59 years ± 11 [standard deviation]) and six women (mean age, 55 years ± 14) with newly created AVFs within 1 week of cannulation between January 2008 and December 2009. Measurements of the intima-media thickness (IMT) were generated by three independent observers who were blinded to outcomes. Intraclass correlation analysis was performed. Cannulation readiness was defined as no extravasation during the first dialysis treatment. RESULTS: By using high-frequency US, the IMT was defined as the sum of a thin echogenic blood-intima interface and a uniform hypoechoic media. The mean IMT of the no extravasation group (0.16 mm ± 0.03) was greater than that of the extravasation group (0.10 mm ± 0.02) (P < .001). A minimum threshold IMT of 0.13 mm (P < .001) was associated with successful cannulation. The mean hoop stress of the no extravasation group (246 kPa ± 57) was lower than that of the extravasation group (530 kPa ± 199) (P < .001). A maximum hoop stress threshold of 248 kPa was associated with successful cannulation (P = .009). CONCLUSION: Venous IMT and hoop stress assessed with high-frequency US can predict cannulation readiness in AVFs that are clinically deemed mature.