Fistula First "Unassisted" evaluation of access dysfunction (eyes, ears, and fingers) Tushar Vachharajani, MD Chief, Nephrology Section W. G. (Bill) Hefner VAMC Salisbury, NC Quality improvement projects focused on vascular access 23 Fistula First Breakthrough Initiative (FFBI) Goal: AVF in use 66% 212: AVF in use 6.2 % 213 Fistula First Catheter Last (FFCL) Workgroup Coalition Goals: AVF in use 68% < 1 % Long Term Catheters (> 9 days) FFCL Leverage the FFBI experience and success Utilize quality improvement processes (PDSA) Focus on the individual patient s experience of care Better health for the ESRD population 2 FFCL Focus Dialysis access is a circuit Access planning Access Monitoring Access infection 3 Successful AVF Blood flow adequate to support dialysis Easily accessible Repetitive cannulation Preferably 6mm or less below skin surface At least 6cm straight segment Fistula Maturation Failure A fistula that was created successfully but never developed to support dialysis Incidence (1-6%) ~ 6% failure rate -NIH sponsored DAC study, JAMA 28
Timing of change in flow and size (A) (B) Overview of problem in established AVF Normal Fistulae 8 7 6 5 Blood Flow 4 (ml/min) 3 2 1.6.5.4 Diameter.3 (cm).2.1 2 W 3 W 4 W 6 W 8W 12 W 2 W 3 W 4 W 6 W 8 W 12 W Early AVF Failure 25 2 15 Blood Flow 1 (ml/min) 5 (C).4.35.3.25 Diameter.2 (cm).15.1.5 (D) 2 W 3 W 4 W 6 W 2 W 3 W 4 W 6 W Asif A, Roy Chaudhury P, Beathard GA: CJASN 1:332 339, 26 Nassar et al - Clin J Am Soc Nephrol 1: 275 28, 26. Access Monitoring KDOQI defines monitoring, as applying physical examination techniques to detect access dysfunction. When done correctly, monitoring can identify most access dysfunction. Monitoring of Fistula Function What do you need to evaluate a fistula? Look Listen Feel When should you evaluate the fistula? Evaluation of Fistula after creation, prior to first use Before each dialysis session Vascular Access Monitoring One minute examination The One Minute Access Exam Look Listen Arm elevation Test Feel Augmentation Test 12
Adequacy of AVF for Size and Flow on PE If fistula diameter was.4 cm or greater, the chance that it would be adequate for dialysis was 89% versus 44% if size was less If fistula blood flow was 5 ml/min or greater, the chance that it would be adequate was 84% versus 43% if it was less Combining the two variables, the chance that it would be adequate was 95% versus 33% if neither of the criteria were met Experienced dialysis nurses had a 8% accuracy in predicting the ultimate utility of a fistula for dialysis The One Minute Access Assessment Access Assessment Components Who Look Listen Feel Arm Elevation Test Augmentation Test Frequency Patient + + + Daily Dialysis Staff + + + + Each Dialysis Robbins Radiology 225:59-64, 22 Other Clinician + + + + + Monthly or problem focused Look! LOOK Identify type of fistula Presence of aneurysms Evidence of infection Evidence of extravasation Look at the skin over the access There should be no redness, swelling or drainage Look for bulges Bulges are sometimes seen when the dialysis needles are put in the same area repeatedly Bulges should Not have shiny skin Ooze blood Skin that peels or does not heal 16 Cannulation Sites Check the Draining Vein (s) Think about normal venous anatomy Is the main draining vein visible? Does it seem to disappear? What is diameter of the draining vein? Can it be readily cannulated? Note prior cannulation sites Is it too deep to stick? Are accessory veins visible? Body of the AVF Is there a pulse present downstream from the anastomosis? Pulse strength indicates down stream resistance Soft indicates low resistance, no stenosis Firm indicates high resistance, suggests outflow stenosis
ARM ELEVATION TEST FEEL Arm Elevation Test Applies only to an AVF Does not work as well in upper arm accesses The vein where the blood flows out Should collapse Become less prominent 19 The access should not be Warm Swollen Painful Thrill Vibration or buzz Felt along full length of the access Pulse Slight beating which feels like a heartbeat Fingers should rise and fall slightly with each beat 2 Detection of Juxta-Anastomosis Stenosis Move finger upward along the draining vein Pulse disappears Vein becomes easily collapsible Palpate the arterial anastomosis Pulse very forceful Thrill is weak or absent Inflow assessment Arterial Inflow Determine if the fistula is flowing or thrombosed Find the arterial anastomosis Know anatomical possibilities Become familiar with local surgical practices Look for surgical scars Compare perfusion of extremity with contralateral side Feel pulse or thrill at arterial anastomosis Check for juxta-anastomosis stenosis AUGMENTATION TEST LISTEN Augmentation Test Put your finger on the outgoing vein Feel for pulse Press down until no blood flows through access Keep finger on vein Feel for pulse on lower part of access Normal AVF and AVG Abnormal AVF Abnormal AVG Normal Pulse will bound and may cause you finger to rise and fall 23 24
Summarize Evidence in Literature? 26 Sensitivity and Specificity of PE 142 consecutive patients Upper arm AVF 95 (67%) Forearm AVF 47 (33%) Diagnosis Sens Spec PE + Angio Inflow stenosis 85% 71% 83% Outflow Stenosis 92% 86% 89% Coexisting inflow-outflow 68% 84% 79% stenosis Central vein stenosis 13% 99% poor Asif et al CJASN 2:1191;27 PE: Fellow vs. Experienced Faculty 45 patients with AVF (75% UA and 25% FA) Fellow received intense training for 1month Angiography on all patients Cohen s κ-value - level of agreement beyond chance between PE and angiography zero no agreement.2 -.4 fair agreement.4 -.6 moderate agreement >.6 substantial agreement Leon and Asif Seminars in Dial 21:28 Fellow vs. Experienced Faculty Analysis of pulse and thrill was most important Arm elevation test Pulse augmentation Diagnosis Fellows Faculty Outflow stenosis 81% 89% Inflow stenosis 8% 83% Central stenosis 79% 11% Leon and Asif Seminars in Dial 21:28 PE skill worth learning 177 dysfunctional AVF PE by trained resident followed by angiography by interventionalist PE by general nephrologist vs. trained resident Comparing angiography and PE general nephrologist moderate agreement Trained resident - strong agreement Coentrao L et al NDT 212
PE in the IN Lab PE vs. normalized pressure ratio 97 AVG Prominent thrill vs. prominent pulse Thrill at venous anastomosis post intervention best predictor Pressure ratios were weak predictors of outcome Access Monitoring Simple, basic tool Cheap And most importantly IT WORKS! Treratola SO et al J Vasc Interv Radiol. 23 Use an organized approach Remember that more than one abnormality can occur Always be systematic Check the entire access