What is dialysis ?
The role of the kidneys is to maintain equilibrium in the body by cleaning the blood of waste products produced by the cells (urea, creatinine, uric acid, etc.) and by eliminating excess mineral salts (sodium, potassium, etc.) from dietary intake.
Patients deprived of kidney function can live thanks to dialysis, generally called "artificial kidney", because dialysis can both clean blood of its waste products and restore normal concentrations of mineral salts.
The artificial kidney, like normal kidneys, cleans the blood through a filtering membrane that lets through the waste products and mineral salts that are small molecules, but retains the larger albumin and proteins molecules that must be preserved.
There are two main types of artificial kidney:
- Hemodialysis that uses an artificial filtering membrane outside the patient’s body (extracorporeal membrane)
- and peritoneal dialysis that uses the peritoneum, a filtering membrane inside the patient’s body (intracorporeal membrane).
What is Hemodialysis ?
Hemodialysis is the most widespread method of dialysis used in France. Blood circulates outside the body in an extracorporeal circuit comprising a dialyzer, a single-use sterile device (a dialyzer for each session) containing a filtering membrane.
This requires the insertion of two needles in a vein specially prepared for this purpose, called a "fistula": one needle to withdraw the blood containing the waste products to be filtered out in the dialyzer, and the other to return the blood cleaned of its waste products to the patient.
Inside the dialyzer, the waste products and excess mineral salts in the blood on one side of the membrane are filtered through the membrane into the dialysis fluid on the other side and eliminated.
This purification of the blood is performed intermittently, generally three times a week (Monday, Wednesday and Friday, or Tuesday, Thursday and Saturday) with sessions that last 4 to 5 hours.
The various hemodialysis treatment modes
The hemodialysis treatment mode will vary depending on the possible or desired degree of independence for the patient.
AURA was and remains today a pioneer in patient training for self-care dialysis because it has been demonstrated that the autonomous patients are those who feel the less the negative effects of the constraints of dialysis treatment : See Professor T. Petitclerc’s article on Autonomy in dialysis >>
Self-care home dialysis is the mode providing the greatest flexibility and optimal preservation of professional and social activity levels.
Home dialysis will of course require specific training for patients to achieve the necessary autonomy in performing all of the treatment procedures: machine preparation, circuit set up, administering the session, and disinfection of the machine.
It also requires the consent and adhesion of the families who agree to undergo the same training and to be present at home during the dialysis sessions to take the necessary measures in the extremely rare cases when patients are no longer able to perform the end of session procedures.
This person is usually in charge of cannulation (puncture) of the fistula, if patients would rather not do it themselves, which is quite often the case.
Patients who do not have facilities at home permitting hemodialysis sessions, or do not have a family member available to be present during sessions, can still be autonomous by going to a self-care dialysis unit for their sessions.
The constant presence of a nurse, who can perform cannulation of the fistula if patients so wish, makes self-care sessions possible without the presence of a family member.
The flexibility in timetable, which must be compatible with opening hours dependent on the presence of a nurse, is however less than with home hemodialysis. Patients who, though perfectly autonomous in their everyday activities, do not want to manage alone their hemodialysis treatment can attend an assisted self-care dialysis unit where the nurse can help them with the preparation and disinfection of the machine.
Because of the considerable ageing of the dialysis patient population (advances in the prevention of renal disease have delayed the average age of starting dialysis, which is now over 65), an increasing number of patients require larger teams of nurses and nurse’s aides.
These patients are treated in dialysis units under medical supervision or in hemodialysis centers; the difference between these facilities being the obligatory presence of a physician in a hemodialysis center throughout the entire session, while he may only be present for part of the treatment in dialysis units under medical supervision.
Treatment in a hemodialysis center is thus for patients presenting renal failure associated with other disorders that the medical team has decided require the constant presence of a physician.