ultrasound assisted puncture of av fistulas in chronic hemodialysis patients

Conditions: Dialysis; Fistula

Summary: the puncture of the vascular access in hemodialysis patients remains challenging even in the hands of experienced dialysis nurses. unsuccessful punctures are associated with resource wastage, traumatism of the av shunts, shortening of the effective dialysis time and poor patient satisfaction. the use of ultrasound by emergency department nurses and technicians without prior ultrasound experience in patients with difficult intravenous access showed in several studies to be very efficient. the investigators expect to achieve similar results in cannulation of av shunts by the dialysis nurse staff after a short learning program. to show this, the investigators aim to conduct a trail where standard cannulation technique (inspection, palpation) will be compared with the ultrasound-assisted method in terms of efficacy, safety and patient satisfaction.

background the vascular access plays a central role in patients with end-stage renal disease undergoing chronic hemodialysis. it is well documented from various previous studies that the confection of the dialysis access and subsequent complications represent a major cause of morbidity, hospitalization and additional costs in chronic dialysis patients. in european countries most patients undergoing chronic hemodialysis use an arterio-venous fistula as permanent vascular access. because of the anatomical differences of each individual and the accompanying chronic diseases affecting patients' vessels, cannulation of arterio-venous fistulas can be very challenging for the nursing personal and puncture failures necessitating repeated attempts are not so rare. the latter are often time-consuming and result in a loss of effective dialysis' time and reduced proceeded total blood volume, are associated with a higher rate of local complications due to repeated traumatisms of the vascular wall and can lead to severe pain with reduced patient satisfaction. in the investigators' dialysis unit, when a dialysis nurse is not able to puncture a fistula she refers to an experienced nurse who tries to cannulate the fistula after thorough visual and palpatory evaluation. in case of another failure, the nursing team refers to the dialysis physician, who performs a short diagnostic bed-side ultrasound of the vascular access to rule out the presence of thrombosis or large hematoma. using ultrasound-guidance provided by the physician or after being informed about the localization and depth of the ideal puncture site, the dialysis nurse tries then to puncture the fistula again. this often leads to a greater loss of time with reduced effective dialysis dose, increased need for human resources and low patient satisfaction. the use of ultrasound by emergency department nurses and technicians without prior ultrasound experience in patients with difficult intravenous access showed in several studies to be very efficient. the method was safe, the procedure rapid, the patients more satisfied, the success rate as high as this from ultrasound trained emergency physicians and the need for physician intervention reduced. the achievement of similar results in av fistula cannulation in hemodialysis patients would be very suitable. the use of ultrasound in patients with recognized difficult fistulas by dialysis nurses after a short ultrasound learning program provided by an index nurse will enable to achieve a higher rate of satisfactory double-needle punctures, usual blood flow rates and full dialysis length with less time loss and increased patient satisfaction. with this study prospective, single-centre, randomized, controlled study the investigators aim to show that the use of ultrasound by dialysis nurses in patients with difficult fistulas makes the punction of the fistulas easier than when assessing the fistula visually and manually. objective the use of ultrasound in patients with recognized difficult fistulas by dialysis nurses after a short ultrasound learning program provided by an index nurse will enable to achieve a higher rate of satisfactory double-needle punctures, usual blood flow rates and full dialysis length with less time loss and increased patient satisfaction. with a prospective, controlled trail the investigators want to demonstrate this hypothesis. methods a portable ultrasound device will be used by the nursing staff after a short learning program. precise location of av shunt segments and depth will be assessed in the case of a difficult shunt. this procedure will be compared with the standard inspection and palpation method.

Eligibility criteria:
inclusion criteria: * forearm or upper arm av-shunt (native, mixed, graft) * patients with recognized difficult vascular access at any time (potentially each patient) * written informed consent exclusion criteria * recent av-shunt surgery (\< 48 h) * presence of large bandages or severe skin lesions in the area of interest * inability to understand the aim of the study and to give a written informed consent * single needle

Keywords: dialysis av shunt cannulation ultrasound outcome