Hemodialysis is defined as the means for artificially removing waste matter such as creatinine, excess water and urea from the blood. This is usually carried out in the case of kidney failure, as in normal conditions, this function is performed by the kidneys. Hemodialysis is one of the three therapies for renal replacement. The other two are peritoneal dialysis and kidney transplant.
Like the kidney, the equipment used in hemodialysis is also a sort of sophisticated filter. The main function of hemodialysis as mentioned above is to filter the blood. This is done through a membrane called the dialyzer. It is nothing but an artificial kidney. Hemodialysis involves removing the blood from the body, filtering it and returning it back into the body after purification.
Several people have contributed to the development of hemodialysis. A brief history of the evolution of Hemodialysis is given below:
The pioneer was Thomas Graham who demonstrated how solute passes through a semi-permeable membrane.
Based on the above principle, Abel Rountree and Turner developed the first artificial kidney, in 1913.
In 1924, for the first time, hemodialysis was performed on a human being by Hass. This was later developed into a clinically operational apparatus in 1945 by Kloff. He successfully treated several patients and after World War II, Kloff donated the 5 dialyzers to big hospitals all over the world with blueprints. This led to the development of the next generation of dialyzers and ultimately the stainless steel Kloff-Bringham dialysis machine.
By 1950, hemodialysis was performed regularly all over the world. But it was not taken seriously due to disbelief in the fact that hemodialysis could be performed repeatedly on a person, and the side effects were also quite adverse. It was not considered as a viable solution to treatment of stage 5 kidney disease.
Dr Nilis Alwall developed an improved version of the Kloff dialyzer which was used up to 1960 to treat 1500 patients. The contribution by Dr Alwall was however, the glass shunt.
Dr Belding H Scribner and Dr Wayne Quinton modified the Dr Alwall’s glass shunts into Teflon ones. They also brought in the use of shunts made out of Silicone Elastomer tubing.
Dr Scribner started the world’s first outpatient hemodialysis center in 1962. Since then there has been a vast development of hemodialysis facilities. Today they are available all over the world.
The chief purpose of hemodialysis is to provide a sufficiently safe and effective treatment to purify the blood in the event of partial or complete kidney failure. Hemodialysis is a process which is important to the continuous seeking of the indexes which are responsible for the controlling of the build up of waste products in the blood.
In actual fact there are several mathematical formulae which are used to calculate the ratios of these impurities. But it is enough here to understand the basic principle of hemodialysis as described above. These calculations are beyond the scope of this brief thesis, but it is sufficient to understand that the doctors and technicians use these equations to make the process of hemodialysis more effective.
There are three types of hemodialysis, conventional, daily and nocturnal. The type of hemodialysis to be used is decided between the patient and the doctor.
This is usually carried out thrice a week for sessions lasting 3 to 4 hours. In this process, blood is drawn from the patient at the rate of 3 to 400 cc per minute. The tube is then linked to a needle which feeds the dialysis machine. The filtered blood is later introduced back into the bloodstream.
This hemodialysis is done at home by the patients themselves. This method is less traumatic, but does however require more vigilant monitoring. If catheters are used then it is simple, but it gets troublesome in the case of fistulas and grafts.
This kind of hemodialysis is more or less the same as the first category, i.e. conventional hemodialysis, the main difference being that it is done during the night while the patient sleeps.
This brief study of hemodialysis should bring one up to date with what it actually means and what to expect in case of undergoing such a treatment. There is also a clear understanding as to how hemodialysis has developed over the years.