The access is a point for entry into the bloodstream so that the patient can be connected to the machine. It is sometimes referred to as the haemodialysis patient's life line because without it, effective, repeated dialysis would not be possible.

THE COMMONEST TYPES OF CHRONIC ACCESS USED NOWADAYS FOR HAEMODIALYSIS -
1) Arterio-venous (AV) fistula
2) Arterio-venous (AV) graft

Arterio-Venous Fistula
This is created internally and is used for prolonged period of time. This involves a small operation to join an artery to vein, allowing arterial blood to flow directly into the vein. The blood vessels of the arm are usually chosen, e.g. at the wrist or at the upper forearm.

Due to the arterial pressure, the vein would increase in size and its walls would thicken. It takes about 4 to 8 weeks for the fistula vein to mature. It allows for high blood flow rates and repeated needle sticks.

Arterio-Venous Graft
The arterio-venous graft (AVG) is an artificial blood vessel used to join artery and vein. It is used when the patient's own blood vessels are too small for fistula construction. Often, these patients are elderly or have pre-existing diabetes mellitus.

The graft, which may be either straight or looped, is placed close to the surface under the skin. The graft may be of an artificial material such as polytetrafluoroethylene (PTFE) or Gortex, or can be obtained from the patient's own vein e.g. the vein in the thigh.

Grafts are most commonly placed in the upper arm, lower arm or thigh. It can be used sooner than a fistula. Two to four weeks is adequate to allow healing and sufficient growth of tissue to stabilise the graft.

TEMPORARY ACCESS
Sometimes, temporary or immediate access is created for patients who need urgent dialysis or those who are waiting for their new fistula to mature. The types of temporary access are subclavian catheter or internal jugular catheter. The catheter is a hollow tubing inserted into the subclavian (below the collarbone) or internal jugular vein (side of the neck ) which has direct access to the heart. Using these access sometimes tend to have problems like blocked catheter from clots or infection at the insertion site. Therefore, extra care has to be taken with temporary access.

CARE OF ARTERIO-VENOUS FISTULA OR GRAFT
1.	Keep the fistula arm raised on a pillow to reduce swelling
2.	The dressing should remain intact and dry at all times. If the dressing is dirty or blood stained, it should be changed.
3.	Observe suture line for signs of infection. Report to doctor-in-charge or nurse if any of these following symptoms are present : • pronounced redness • warmth • fever • bleeding or discharge • increase pain • tenderness
4.	After the sutures are removed, the fistula arm may be cleansed with soap and water in the usual manner.
5.	As soon as post operative pain has subsided, start arm exercises by squeezing a rubber ball or using a rolled up wash cloth for 5 minutes, alternating squeezing and relaxing the hand. Do up to 6 times a day. This helps to develop the fistula.
6.	Do not allow blood pressure, blood taking or intravenous administration on the fistula arm.
7.	Do not wear constrictive clothing, bangle, watch or hang a bag over the arm or carry heavy objects on the extremity of the fistula arm.
8.	The doctor-in-charge will inform you when the fistula is ready for use.

 

GENERAL GUIDELINES
1.	Keep fistula or graft site clean and dry.
2.	Feel for thrill or buzzing sensation at both ends of the fistula or graft in the morning when you wake up and at night before you go to sleep. Seek advice from your doctor or nurse if the thrill or buzzing sensation is absent.
3.	Inspect fistula for redness, swelling, tenderness or warm to touch to detect infection. Report to the doctor or nurse if any of these symptoms are present.
4.	Avoid constrictive clothing, bangle, watch or hang a bag over the arm or carry heavy objects on the extremity of the fistula arm which may block off the fistula.
5.	Remember that no taking of blood pressure, blood taking or intravenous administration should be done on the fistula arm. Take measures to prevent sleeping on the fistula arm.
6.	Continue arm exercises if the fistula is still not well developed.
7.	Wear an arm guard to protect the fistula if participating in contact sport or labour work.
8.	Wash the fistula arm thoroughly with antiseptic solution before dialysis.
9.	Avoid excessive pressure on the puncture sites after dialysis. Apply digital pressure so as to prevent bleeding.
10.	Rotate needling sites to prevent aneurysm and pseudo-aneurysm and also to allow healing of the puncture sites.
11.	After dialysis, the dressings should remain intact for about 6 hours . Ensure that the thrill or buzzing sensation is still present on the fistula.
12.	If injury or profuse bleeding occurs at fistula site, apply pressure over the bleeding area to stop bleeding and seek immediate medical attention at the nearest A&E department.

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