Process of Hemodialysis

Process of Hemodialysis

Hemodialysis comes from the Greek word “Hemo” which means blood. Dialysis is a filtering process. So hemodialysis by definition means filtering of the blood. Under normal conditions, the purification of the blood is done by the kidneys

A permanent access is created surgically by a doctor who creates a channel to the bloodstream to enable a diversion of the blood into a dialysis machine and then back into the body. The point of entry is known as a graft or fistula.

There are essentially three methods of removal of waste products like urea, creatinine and excess water from the blood. Hemodialysis is one; the other two are peritoneal dialysis and renal transplant. Hemodialysis is the mildest and the most flexible of all the three processes.

Preparation for Hemodialysis

At a particular stage known as 4 CKD, if the glomerular filtration rate (GFR) falls below 30 cc/min, it may be necessary to decide whether to go in for peritoneal dialysis hemodialysis, or a kidney transplant. To those who choose hemodialysis, the access point turns out to be a lifeline. The success of the therapy depends on the amount of preparation and awareness. A major hurdle in hemodialysis is the incorrect positioning of an arteriovenous access.

The three main choices arteriovenous access are an AV fistula, catheter and an AV graft. These three categories are described below:

Catheter: A catheter is a plastic tube which is inserted into a large vein in order for dialysis to be carried out. A catheter is used in case there is not sufficient time for the development of a fistula. The advantage of using a catheter is that it is immediately convenient and rules out pain caused by a needle. However, the downside is that there is a susceptibility to infection, and the possibility of stenosis (narrowing of the blood vessels) occurring.

AV Fistula: Developed in 1996, the AV fistula was widely popular in the early development of dialysis. Here a vein and an artery are joined together to make a direct connection between both the vessels. There is an increased pressure between the connected vessels which results in the hardening and expansion of the veins. The thickened area makes it easy for insertion of a needle or a canula. If care is taken, an AV fistula can be used for years. There are some known cases where they have been used for 20 to 30 years.

Graft: The third type of access is known as the arteriovenous graft. The material used is a Teflon-like plastic known as “GORE-TEX” which was very popular in the US in the 1970s. The main advantage of the graft is that it is easier to install than the AV fistula, and the time required for it to develop is also lesser that that of the AV fistula – just about 2 weeks. However, as it is a synthetic material, the body treats it as a foreign body and stenosis and clotting develops easily. There is a high risk and they have to be regularly replaced.

Care of Blood Vessels

Given below are a few steps if taken, will lead to a more effective treatment of hemodialysis. During the course of hemodialysis, the veins must be kept in good condition at all times.

  • Use of needles should be restricted to a minimum.

  • Small gauge needles should be used whenever possible.

  • The preffered site for drawing blood should be the back of the hand.

  • In the case of frequent needle insertions, the sites should be changed on a rotation basis.

  • The veins in the elbow (antecubital fossa) and in the upper limb (cephalic vein) should be avoided.

  • If any medication can be given orally, it should not be given intravenously.

  • Hand exercises can help in making an easier withdrawal of blood.

  • A minimum level of hydration is encouraged just before the insertion of a needle.

Minimum Requirements for Hemodialysis

An individual cannot pose as a hemodialysis technician unless he or she has the qualifications and training as a category G hemodialysis technician as given below:

  • Education up to high school level.

  • Able to read and write and speak English clearly.

  • Know basic mathematics such as the use of decimal points and fractions.

  • Should be physically fit and dexterous enough to perform the basic functions required for administering healthcare.

  • Should possess documentary proof of being competent in all the above mentioned abilities.

  • Should have training to a minimum level of competency by WAC 246-826-302.

  • Any dialysis facility who forwards the application for a hemodialysis technician certification should verify that the applicant has successfully completed all the core competency levels and minimum training standards required under chapter 18.135 RCW and the rules thereof.