Understanding Your Dialysis Access

Your access is the point where blood leaves your body for the machine and returns to it. It is the part of your treatment you are most responsible for between sessions, and the part most worth understanding properly — a well-cared-for access can last years, and problems caught early are usually fixable.

Fistulas, grafts, and catheters compared

There are three kinds of access, and which one you have depends on your veins, your general health, and how urgently treatment had to start.

An arteriovenous fistula is made by a surgeon joining an artery to a vein, usually in your arm. Over the following weeks the vein thickens and enlarges under the stronger flow, until it is robust enough for needles. It is the first choice for most people, because it generally lasts longer and has fewer problems with infection and clotting than the alternatives. The trade-off is that it has to be created well ahead of when it is needed.

An arteriovenous graft uses a short piece of soft tube to join an artery and a vein. It is the second choice, used when your own vein is not suitable for a fistula. It can be used sooner than a fistula, but it carries a higher risk of clotting and infection.

A catheter is a soft tube placed into a large vein, usually in the neck. It can be used immediately, which is why it is what most people start with when dialysis begins urgently. It is generally a temporary measure — occasionally a permanent one — and it carries the highest infection risk of the three, because it is an opening that runs from outside your body directly into a large vein.

If you are currently using a catheter, it is reasonable to ask your nephrologist whether a fistula is planned for you and when. Because a fistula needs time to mature before it can be used, that conversation is worth having earlier than feels necessary.

Daily care for your access site

If you have a fistula or a graft:

• Wash the area with antibacterial soap every day, and always before dialysis
• Do not scratch the skin over it, and do not pick at scabs
• Check the blood flow several times a day by resting your fingers on it and feeling for a vibration — this is called a thrill or buzz
• Ask the staff to rotate the needle sites rather than using the same two points every session
• Keep watch for redness, warmth, or any pus forming
• Do not let anyone take blood, insert a drip, or measure blood pressure on that arm
• Avoid sleeping on it, carrying heavy bags over it, or wearing tight sleeves, watches or jewellery on that side

Feeling for the thrill is the single most useful habit to build. It takes a few seconds, and it is how you find out that an access has clotted while there is still time to save it. Make it part of something you already do daily so you do not have to remember it separately.

If you have a catheter:

• Keep the dressing clean and dry at all times
• Let the staff clean the site and change the dressing at each session — this is not something to do yourself unless you have been trained
• Never open the catheter to the air
• Keep a spare dressing kit at home in case the dressing is damaged or gets wet
• Do not swim, and follow the advice you were given about showering

Warning signs to report immediately

Call your center by phone if you notice any of these. None of them should wait for your next scheduled session.

• You cannot feel the thrill in your fistula or graft, or it feels clearly different from usual
• Bleeding from a needle site that continues for more than about thirty minutes after treatment despite steady pressure
• Redness, warmth, swelling, tenderness or pus at the access site
• A fever, chills, or feeling suddenly unwell — with a catheter especially, this can mean a bloodstream infection
• Your hand on that side becomes cold, pale, numb or painful
• Swelling of the whole arm, or new prominent veins across your chest or shoulder

A change in the thrill and a fever with a catheter are the two that matter most. An access that has clotted can often be reopened if it is dealt with quickly, and a catheter-related infection can become serious fast.

Your nurses check your access at every session and will teach you what yours should normally feel like. Ask them to show you where to feel for the thrill and what your baseline is — it is much easier to notice a change when you know exactly what you are comparing against.