Nephrology Directorate Subject: Objective: Prepared by: Cannulating AV Fistula using Buttonhole Technique To enable the safe insertion and removal of needles into arteriovenous fistulae using the buttonhole technique. Sojan Thomas, Nephrology Specialist nurse (Vascular access & Anaemia) Approved by: Nephrology Clinical Governance Group (March 2014) Evidence Base: Rank: Date of Issue: April 2014 Review Date: October 2016 Evidence base These guidelines have been derived using the following evidence base: Fistula First (2005) National Vascular Access Improvement Initiative Renal Association Guidelines Vascular Access for Haemodialysis 5th Edition 2008-2011(Guidelines 4.2) Dr R Fluck and Dr Mick Kumwenda Section 4.2 Maintenance of Vascular Access. Audit Plans The following subjects would be suitable topics for audit: Infections (local and bacteraemia) related to buttonhole cannulation Patient satisfaction with buttonhole technique. Training and implementation Vascular access training for haemodialysis access is led by the vascular access coordinators and in the individual dialysis units by the ward managers and team leaders. The buttonhole technique will be led by identified haemodialysis nurses in each dialysis unit. Nurses undertaking buttonhole cannulation must have received specific training in the technique including observed practice and assessment of competence. Changes from previous guidelines No previous guidelines for buttonholing technique.
Introduction The Arteriovenous fistula (AVF) remains the gold standard access for Haemodialysis showing better survival and complication rates than grafts and catheters. An AVF should be Patent Palpable with a bruit present Clean and free from signs of infection Able to deliver adequate Haemodialysis The puncture of an AVF is a very important procedure carried out numerous times by dialysis nurses over the course of each day. The correct puncture site and technique are a fundamental factor for an acceptable dialysis session and for a happy comfortable patient. Current recommended practice is that puncture sites are rotated each dialysis session to allow good healing and to avoid complications such as haematoma, stenosis, infection and aneurysm formation. In clinical practice this so called rope ladder technique is often not employed. Both patients and nurses prefer to cannulate the fistula in a similar place to previous attempts to ensure successful needling and reduce the discomfort caused by cannulation. This area needling technique is thought to lead to aneurysm formation as the vessel wall is weakened by repeated cannulation in the same area. The buttonhole technique is a method of puncturing native arterio-venous fistulas (AVF) where the exact same point of puncture and alignment are used in consecutive dialysis sessions. By using exactly the same entry point for a period of weeks, a channel is formed from the surface of the skin to the fistula, surrounded by a wall of scar tissue. With care, this tunnel can be repeatedly used to access the fistula. Emerging evidence suggests that the buttonhole technique may offer the patients advantages in long term survival and patency of their fistula. These benefits include less pain on cannulation, improvements in the cosmetic appearance of the fistula and reduced bleeding time at the access site once dialysis is completed and the needles have been removed. Hazards of cannulating fistulas The potential hazards of cannulating an arteriovenous fistula include: Infection Haemorrhage Risk of air embolism Risk of tissue infiltration Arteriovenous fistula damage Needle stick injury Contamination from blood leakage Venous needle dislodgement during Haemodialysis Cannulation using the buttonhole technique carries with it the same risks in the short-term. There is an increased risk of both local infection at the fistula site and bacteraemia in patients using the buttonhole technique. However, it is suggested that this increased risk is related to poor skin asepsis prior to cannulation.
Patient suitability Buttonhole technique is potentially suitable for all patients with an arteriovenous fistula. The most suitable patients would include those patients who are on home haemodialysis or more frequent dialysis regimes, those with limited needling sites, patients with aneurismal fistulas and those patients who wish to self-cannulate. Buttonhole technique is not suitable for patients with an arteriovenous graft. Patients will be identified by their Named nurse, who will liaise with the lead nurse for buttonhole technique in that unit. The technique will be discussed with patients and they will be given written information. A start date will be agreed with the patient. Staff involved in cannulation Ideally one and at most two track formers (nurses) should commit to undertaking each cannulation of the patient until the blunt needles are established. This is because the same direction, angle and depth must be followed for every cannulation whilst the track is in development. Multiple needlers are probably less likely to be able to achieve this. One nurse should then follow a patient s dialysis schedule until blunt needling is established. Selection of the sites for the formation of the tunnel tracks The track former nurse should visually assess and palpate the patient s fistula at each dialysis session. Using careful assessment of the fistula the track former nurse should select optimal sites for the arterial and venous needle Keep at least 5cm away from the anastomosis of the fistula The two needles should be at least 4-5cm apart and ideally 8-10cm apart to reduce/prevent recirculation The track former should try to avoid previous heavily scarred or aneurysmal areas whenever possible. If it cannot be avoided then a site at the base of the aneurysm rather than directly into it should be chosen Avoid dips and curves in the vessel Needles should always be in the direction of the blood flow. N.B. There should be an assessment made of the pathway for cannulation. Buttonholes cannot be created in a retrograde direction. If direction of blood flow is not clear consider duplex scan to determine. Seek medical review if appropriate. A 'thrill' should be felt for and a 'bruit' should be heard by using a stethoscope before any needles are inserted. If there are any doubts about the fistula then medical or surgical advice should be sought. It is necessary to identify and avoid areas that may be hard as this may indicate the presence of clots. It is also recommended to identify areas that may be inflamed as this may indicate the presence of infection. Local anaesthetic using Lidocaine should not be used whilst establishing the track. Alternative topical analgesic cream (e.g. EMLA) or Ethyl Chloride spray should be offered instead until track is established. Skin cleansing for fistulae Patients should be requested to wash their fistula limb with soap and water upon arrival in the dialysis unit. An alternative is for the patient to clean the arm with a Clinell Wipe.
Chlorhexidine Gluconate 0.5% in 70% v/v alcohol solution (Hydrex Pink ChlorhexidineGluconate 2.5%) is the preferred solution for skin cleansing. ChloraPrep (Frepp 1.5 ml applicaror) 2%w/v / 70% v/v Cutaneous Solution - is preferred use after scab removed If Allergic to Hydrex Pink, 10% Iodinated Povidone (Betadine) can be used to clean the fistula site. patient cannot be buttonholed If allergic to available antiseptic solutions Needle choice New fistula Established AV fistula Use 17g conventional needles for new AV Use patient s normal size conventional Fistula and increase gauge as tolerated. needle. When tract established change to blunt needles and allow other staff to cannulate unless patient is self- cannulating. Documentation Please document assessment & any needling issues of the fistula each time on the Buttonhole Cannulation Documentation Record & CybeRen. Pre-needling assessments can be entered as free text in assessment column under the predialysis tab & issues can be entered as free text in assessment column under postdialysis tab. In post dialysis tab there is also 2 tick box for clotting & infiltration. Equipment List Item Apron Visor Gloves Clean trolley Dressing pack 2 x AV fistula needles- conventional or blunt 2 x Steri pic / blunt needle 2 x 10 ml syringes 0.5 in 70% Alcoholic Chlorhexidine 1x 2% ChloraPrep Frepp sponge Tourniquet - patient s own/ or disposable Alcohol gel Tape
Buttonhole track Gauge of needle Direction of needle Arterial Venous Angle of needle. Art. 30, 35, 40, 45 degrees Ven, 30, 35, 40, 45 degrees Nursing Procedure Procedure Rationale 1. Check the Direction & angle of needle on Buttonhole Cannulation Documentation Record To avoid multiple track formation & to avoid missing the track 2. Put on apron and visor To reduce risk of infection and cross infection. 3. Wash hands and ask patient to wash their To reduce risk of infection. arm with soap and water, including buttonhole sites. If patient has mobility issues Clinell wipes should be used as an alternative. 4. Clean trolley and apply alcohol gel to hands. 5. Prepare dressing pack and other equipment. Wash, dry and apply alcohol gel to hands 6. Apply alcohol gel to hands and put on nonsterile gloves. 7. Place towel from pack under arm supporting arm on a pillow. The arm must be positioned in the same way each session when forming the track. 8. Palpate AV fistula to ensure thrill present. Assess and discuss any swollen, bruised, sore, or inflamed areas with the patient. Seek advice from senior staff if indicated. 9. Soak 2 pieces of gauze with 0.5 in 70% alcoholic chlorhexidine solution 10. Clean each buttonhole site with a separate chlorhexidine soaked gauze 11. Before removing the scab the skin should be cleaned for 30 seconds with the selected To ensure all equipment that is required is available. To reduce the risk of cross-infection. To aid patient comfort. To ensure AV fistula is suitable to be needled. Advice is that the scabs should not be softened as they are more likely to be removed whole if they are not soft Scab heavily colonised with bacteria.
skin cleaning solution dependant on patient s allergies and skin sensitivities. Whilst cleaning the skin stretch the skin away from the scab to loosen it. It should then come off easily with the scab picker attached to the needles. Allow the skin to dry for 30 seconds before removing the scab. Never remove a scab with the fistula needle as this may contaminate the needle and introduce bacteria into the track! Do not cannulate unless all scab is removed, 12. The scab should be assessed at each cannulation. Any change in size should be documented. If the scab becomes more difficult to remove or fragments this should be recorded. If the scab starts to become difficult to remove a new buttonhole should be created. 13. Clean sites with 1x 2% alcoholic chlorhexidine Frepp sponge, allow to dry for 30 seconds. Use the separate sponge for both sites. If an allergy to Chlorhexidine develops use betadine solution. If an allergy develops to Betadine antiseptic solution do not use the buttonhole technique for that patient. 14. Apply tourniquet (if required. If tourniquet used to track form it must always be used) and stabilise vessel, pulling skin taut. 15. Insert the needles at the same angle and direction (see the Buttonhole Cannulation Documentation Record) for every cannulation (bevel facing up). 16. Once flashback is observed the angle of the needle can be lowered. Advance needle down the centre of vessel. If you have difficulties inserting the needle hold needle by the tubing not the wings and in a gentle movement wiggle from side to side advancing the needle into the track. 17. Release tourniquet and tape needles as per unit guideline. Increase risk of infection if buttonhole track is needled following bleeding. To reduce risk of haemorrhage and damage to the vessel. Reduces pain and allows easier cannulation. To ensure buttonhole tract is not damaged. Needle must go through established puncture tunnel and not cut any adjacent tissue. To ensure needles are adequately secured to prevent needle dislodgment. 18. Confirm good flow using syringe. To ensure flow is good enough for dialysis 19. No more than 2 unsuccessful attempts should be made with a bluntl needle at each site. 20. Do not go back to using a conventional needle. Handover to senior nurse for further attempt using blunt needle, if this is not successful, then use a conventional needle in a different site well away(at least 1.5 cm) from the buttonhole track and entry site of buttonhole To ensure that the buttonhole is not damaged. See Vascular Access Nurse. To ensure buttonhole track is not damaged. Seek advice from Vascular Access Nurse.
21. Once patient is connected to the machine ensure that fistula needles are well secured to prevent accidental dislodgment. Ensure there is a little slack in the line before taping. 22. At the end of dialysis the fistula needles are removed. Use sterile gauze, folded, over the needle exit site. Hold the gauze in place, by using even pressure, until it has been established by visible inspection that the needle exit site has completely stopped bleeding. 23. Clean both needling site using same cleaning agent used before needling & Tape sterile folded gauze over the exit. Only allow the patient home / discharged from the dialysis unit if the bleeding from the needle exit site has completely stopped. Advise the patient to remove this dressing the following day if no signs of bleeding. 23. Complete the Buttonhole Cannulation Documentation Record each time To ensure needles are secure. To reduce the risk of needle dislodgement. To ensure that the needle site has completely stopped bleeding before discharge form the dialysis unit. To Avoid needling complications Ongoing track care Action Rationale 1. For new fistulas, increase needle gauge To keep track patent. until satisfied blood flow achieved & once track formed then move to blunt needles. For established fistulas please be advised by track former. 2. Keep same angle of needle insertion To protect/ reduce damage to the track that has been formed 3.Changing to blunt needles will be individual to each patient but look for these signs Sharp needles glide in smoothly without any resistance? Can you see a round hole once the scab is removed? Does it look well healed? N.B This should not be before two weeks i.e. six dialysis sessions. 4. Complete the Buttonhole Cannulation Documentation Record each time 5. When starting to use blunt needles do not use excessive force when inserting into buttonhole site. They should glide in without force.
Troubleshooting Problem Difficulty to remove the scab Infiltrations- blows. Excessive bleeding Infected/blown buttonhole Pain/ difficulty in forming tract Large amounts of subcutaneous tissue may be a barrier to successful buttonhole development. Potential solution Leave a sterile saline socked gauze over the scab for 2-5 min. This will often help to remove the scab easily Remove needle in the usual way and manage infiltrations as with conventional needles at least 1.5cm away from the track. Indicates that the track wall may be getting cut. If bleeding not controllable remove the needle & manage with conventional needles at least 1.5cm away from the track. A Doppler scan my be advisable If using different site other than buttonhole, due to infection or resting due to blow; then stay at least 1.5cm away from buttonhole site to prevent damage to track. Check with the doctor and vascular access nurses to ensure they are aware of infection / blow. If a site is not progressing or there is a lot of pain then abandon and choose another site. Longer needles available Potential benefits of Buttonhole cannulation Potential benefits include: Promotes patient self cannulation Less painful cannulation for patient Prolongs AV Fistula life, with reduction in aneurysm formation Fistula has better cosmetic appearance Less incidence of needling problems Fewer infiltrations Less risk of needle stick injury for staff and patients due to blunt needles Decreases hospitalisations related to access infections and complications