VASCULAR TECHNOLOGY PROFESSIONAL PERFORMANCE GUIDELINES Evaluatin f Dialysis Access This Guideline was prepared by the Prfessinal Guidelines Subcmmittee f the Sciety fr Vascular Ultrasund (SVU) as a template t aid the vascular technlgist/sngrapher and ther interested parties. It implies a cnsensus f thse substantially cncerned with its scpe and prvisins. This SVU Guideline may be revised r withdrawn at any time. The prcedures f SVU require that actin be taken t reaffirm, revise, r withdraw this Guideline n later than three years frm the date f publicatin. Suggestins fr imprvement f this guideline are welcme and shuld be sent t the Executive Directr f the Sciety fr Vascular Ultrasund. N part f this guideline may be reprduced in any frm, in an electrnic retrieval system r therwise, withut the prir written permissin f the publisher. Spnsred and published by: Sciety fr Vascular Ultrasund 4601 Presidents Drive, Suite 260 Lanham, MD 20706-4831 Tel.: 301-459-7550 Fax: 301-459-5651 E- mail: svuinf@svunet.rg Internet: www.svunet.rg Cpyright by the Sciety fr Vascular Ultrasund, 2012. ALL RIGHTS RESERVED. PRINTED IN THE UNITED STATES OF AMERICA.
Evaluatin f Dialysis 2014 Evaluatin f Dialysis Access PURPOSE T determine patency and flw adequacy f a dialysis access fistula r graft and/r identify abnrmalities that may be present. COMMON INDICATIONS Failure t mature n basis f physical examinatin Symptms and signs f disease present Signs f access site malfunctin during dialysis (e.g., lw bld flws, kt/v, recirculatin times, r increased venus pressure) Mass assciated with an AVF/AVG Lss f palpable thrill f AVF/AVG Arm swelling Hand pain, pallr, and/r digital ulceratin (evaluatin fr arterial steal syndrme) Difficult cannulatin by multiple persnnel n multiple attempts CONTRAINDICATIONS AND LIMITATIONS Cntraindicatins fr evaluatin f dialysis access are few; hwever, sme limitatins exist and may include the fllwing: Open wunds n the skin surface Dialysis r shuntgram perfrmed n the same day (flw vlumes may be lwer, cmpressin f access fr pssible steal phenmenn nt recmmended) PATIENT COMMUNICATION Intrduce self t the patient and explain why the evaluatin is being perfrmed and indicate hw much time the exam will take. Explain the prcedure t the patient, taking int cnsideratin the age and mental status f the patient, and ensure that the patient understands the necessity fr each aspect f the evaluatin. Respnd t questins and cncerns abut any aspect f the dialysis access evaluatin. Refer specific diagnstic, treatment r prgnsis questins t the patient's physician. 2 Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America.
Evaluatin f Dialysis 2014 PATIENT ASSESSMENT Patient assessment must be perfrmed befre Evaluatin f the Dialysis Access is perfrmed. It includes assessment f the patient s ability t tlerate the prcedure and an evaluatin f any cntraindicatins t the prcedure. The technlgist/sngrapher/examiner shuld: Obtain a cmplete, pertinent histry by interview f the patient r patient s representative and review f the patient s medical recrds whenever pssible. A pertinent histry includes: Review f perative ntes Surgical cnfiguratin Revisins/fistulagrams Current status f dialysis Verify that the requested prcedure(s) crrelates with the patient s clinical presentatin Perfrm a limited r fcused physical exam, including bservatin and lcalizatin f any signs r symptms f access dysfunctin. Determine access patency by the presence f a palpable thrill as well as the strength and cnsistency f thrill thrughut the access (Nte: prminent pulsatility is abnrmal) Prvide a visual inspectin f the limb and access site nting scars, areas f redness, ecchymsis, swelling, dilatatin, and presence f cllateral vessels PATIENT POSITIONING Patient psitining is mst ften supine, with the arm relaxed and extended ut t the side with area t be evaluated clsest t the sngrapher. Fr patient cmfrt, it is helpful t supprt the arm n a bedside table/pillw. Thigh fistula/graft shuld be evaluated in the supine psitin. Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 3
Evaluatin f Dialysis 2014 INSTRUMENTATION Use apprpriate duplex instrumentatin, which includes display f bth twdimensinal structure and mtin in real-time and Dppler ultrasnic signal dcumentatin with: Spectral analysis with clr Dppler imaging Imaging carrier frequency f at least 5-10 MHz Dppler carrier frequency f at least 3.0 MHz Digital strage capabilities Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 4
Evaluatin f Dialysis 2014 EXAM PROTOCOL Thrughut each examinatin the technlgist/sngrapher/examiner shuld: Observe the sngraphic characteristics f the nrmal and abnrmal tissues, structures, and bld flw t allw necessary adjustments t ptimize exam quality Assess and mnitr the patient s physical and mental status, allwing mdificatins t the prcedure plan accrding t the patient s clinical status Analyze sngraphic findings t ensure that sufficient data is prvided t the physician t direct patient management and render a final diagnsis Dppler is used primarily t dcument patency f the vessels and fistula/graft as well as t identify any areas f stenses in the inflw artery, anastmsis, within the fistula/graft r in the utflw vessels. Dppler spectral analysis is perfrmed in the sagittal plane. All Dppler samples must be perfrmed at an angle f 60 degrees r less with respect t the directin f bld flw. Dppler cursr alignment is recmmended parallel t the vessel walls. Representative wavefrms shuld be recrded. When a stensis is identified, velcities shuld be dcumented in the stensis, prximal t the stensis and distal t the stensis. Flw vlumes shuld be calculated and used t determine fistula maturatin. Functinal disrders can als be identified using flw vlumes. Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 5
Evaluatin f Dialysis 2014 ARTERIOVENOUS FISTULA Fllw a standard exam prtcl fr evaluatin f the dialysis access. The standard exam includes assessment f the inflw (afferent) artery, arterial anastmsis, and utflw (efferent) vein. INFLOW ARTERY (afferent) Obtain PSV/EDV at least 2 cm cephalad t the arterial anastmsis PSV shuld be >150 cm/s with lw resistance wavefrm Measure flw vlumes (FV) using system sftware Obtain 2D diameter using B-Mde imaging Optimize spectral windw and btain Time-Averaged Mean Velcity (TAMV) Open sample vlume (slightly wider than vessel) Use a 60-degree angle Measure 2-3 cardiac cycles Nrmal range 800 ml/min t 2500 ml/min ARTERIAL ANASTOMOSIS Obtain spectral Dppler Measure PSV (may be very elevated) and cmpare t the PSV btained in the afferent artery Nte any audible bruit Evaluate with B-Mde imaging (nte any thickening/narrwing) Significant (>50%) anastmtic stensis is indicated when velcity triples cmpared t the afferent artery velcity. OUTFLOW VEIN (efferent) Measure vein diameters (transverse, inner wall-inner wall) Alng curse f vein (prximal, mid, distal) when indicated fr fistula maturatin Mature fistulas have a diameter 4 mm At areas f narrwing Residual lumen f < 2-3 mm indicates significant narrwing Of branches (als nte lcatin in relatin t arterial anastmsis) Measure depth (skin line t tp f vessel) when indicated fr fistula maturatin Mature fistulas have a depth 5 mm. Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 6
Evaluatin f Dialysis 2014 Nte any extrinsic findings (hematma, serma, aneurysm, pseudaneurysm) Measure flw vlumes using system sftware (see Inflw Artery sectin fr technique) Select the mid-prtin f the vein in an area that is straight and nntapering Nrmal range 800 ml/min t 2500 ml/min Dppler evaluatin Significant stensis alng the efferent cnduit is indicated when velcity dubles alng cntiguus segments. Obtain spectral Dppler at areas f increased turbulence/narrwing (if apprpriate) PSV > 400 cm/s, EDV >250 cm/s indicates significant utflw vein stensis Measure PSV and FV cephalad t areas f stensis PSV < 150 cm/s and FV < 800 ml/min indicates pr functining f the AV access. Fllw the venus utflw t its rigin Cephalic arch and basilic vein swing pints are cmmn sites fr stensis ARTERIOVENOUS GRAFT Fllw a standard exam prtcl fr evaluatin f the dialysis access. The standard exam includes assessment f the arterial inflw, arterial anastmsis, graft bdy, venus anastmsis, and utflw vein. Measure PSV/EDV at the fllwing lcatins Arterial inflw Arterial anastmsis Graft bdy (mid) Venus anastmsis (cmmn site f stensis) Outflw vein Areas f increased turbulence/narrwing Diagnstic criteria fr significant anastmtic r c Measure flw vlumes Straight AVG Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 7
Evaluatin f Dialysis 2014 Mid prtin f the cnduit Lp AVG Arterial side (mid) Venus side (mid) ADDITIONAL IMAGES Stents Stents may be present in the dialysis access (arterial inflw, graft, r utflw vein). T assess stent patency, Measure velcities prximal, mid, and distal stent Diminished FV in the absence f utflw vein stensis If FV are lwer than 800 ml/min withut bvius utflw vein stensis Evaluate central venus utflw (subclavian and brachicephalic veins), t assess pssible central vein stensis r cclusin. Multiple venus branches near the shulder may indicate central vein stensis/cclusin Duplex the subclavian and axillary arteries t evaluate fr stensis Arterial inflw disease is rare, but mre likely in elderly, diabetics and thse with lng-standing renal disease Nte: AVF branches may als divert significant flw vlume and reduce flw alng the main cnduit. Steal Phenmenn Digit disclratin, cmplaints f numbness, r pain in the hand suggests a steal phenmenn may be present Dcument arterial flw beynd the arterial anastmsis Flw shuld be twards the hand, hwever all AV accesses steal. Gal f steal testing is t identify clinically significant steal. If it is retrgrade, cmpress the dialysis access (cntraindicated if fistula/graft had been accessed the same day) Nrmalizatin f flw with cmpressin cnfirms a steal phenmenn Clinically significant steal is uncmmn Cnsider btaining an rder fr digit brachial indices with and withut access cmpressin t cnfirm significance f steal phenmenn Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 8
Evaluatin f Dialysis 2014 REVIEW OF THE DIAGNOSTIC EXAM FINDINGS The technlgist/sngrapher/examiner shuld: Review data acquired during the Evaluatin f the Dialysis Access t ensure that a cmplete and cmprehensive evaluatin has been perfrmed and dcumented. Explain and dcument any exceptins t the rutine Evaluatin f the Dialysis Access examinatin prtcl (i.e., study limitatins, missins r revisins). Recrd all technical findings required t cmplete the final diagnsis s that the findings can be classified accrding t the labratry diagnstic criteria in the patient s medical recrd. Dcument the exam date, clinical indicatin(s), technlgist perfrming the exam and a summary f the exam results in the patient s medical recrd Alert health care prvider when immediate medical attentin is indicated based n exam findings and accrding t labratry prtcl. Dcument in patient s medical recrd. PRESENTATION OF EXAM FINDINGS Preliminary results may be prvided as established by internal guidelines in individual labratries. Present recrd f diagnstic images, data, explanatins, and technical wrksheet t the interpreting physician t use in rendering a diagnsis and fr archival purpses. EXAM TIME RECOMMENDATIONS High quality and accurate results are fundamental elements f the dialysis access examinatin. A cmbinatin f indirect and direct exam cmpnents is the fundatin fr maximizing exam quality and accuracy. Indirect exam cmpnents include pre-exam prcedures: btaining previus exam data; pre-exam paperwrk; exam rm and equipment preparatry activities; patient assessment and psitining; and, pst-exam prcedures: cleanup; cmpiling, prcessing, reviewing exam data fr preliminary and/r frmal interpretatin; patient cmmunicatin; exam charge and billing activities. Recmmended time alltment is 25 minutes. Direct exam cmpnents include equipment ptimizatin and the actual hands-n examinatin prcess. Recmmended exam time is 35-45 minutes. If additinal testing is indicated fr steal phenmenn an additinal 15-30 minutes will be required. Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 9
Evaluatin f Dialysis 2014 REFERENCES 1. NKF-K/DOQI clinical practice guidelines fr vascular access. AM J Kidney Des 48 [Supp 1]:S248-S273, 2006. 2. Hubbard J, Markel K, Bendick P, Lng, G. Distal Revascularizatin-Interval Ligatin (DRIL) fr the treatment f dialysis access steal phenmenn. Jurnal f Diagnstic Medical Sngraphy, Nv 2009; Vl 25:pp. 316-322. 3. Back MR, Maynard M, Winkle A, Bandyk D. Expected flw parameters within hemdialysis access and selectin fr remedial interventin f nnmaturing cnduits. Vasc Endvascular Surg. 2008 Apr- May;42(2):150-8. 4. Rbbin M, Chamberlain N, Lckhart ME, Gallichi M, Yung CJ, Deiehi MH, Alln M. Hemdialysis arterivenus fistula maturity: US evaluatin. Radilgy. 2002 Oct;225(1):59-64. 5. Cmeaux ME, Harkrider WW.: Clr Dppler imaging evaluatin f venus hypertensin in the upper extremity cmplicating vascular access graft. J Vascu Technl 1994; 18 (1): 45-47. 6. Eliades SJ, Eliades J.: Hemdynamic changes during dialysis in the arm and digits in the arms and digits f patients with plytetraflurethylene arterivenus grafts. J Vasc Technl. 1998, 22 (3): 143-151. 7. Singh P, Rbbin ML, Lckhart ME, Alln M. Radilgy. Clinically immature arterivenus hemdialysis fistulas: effect f US n salvage. 2008 Jan;246(1):299-305 Cpyright by Sciety fr Vascular Ultrasund, 2012. All Rights Reserved. Printed in the United States f America. 1 0