LISA CLARK: I'm Lisa Clark. Welcome, and thank you for joining us for this webcast. Make no mistake, the diagnosis of kidney disease is a serious medical issue, but the last 50 years have seen the kinds of medical advances which make kidney disease something you can live with. One of the most important lifesaving advances, dialysis, was invented during World War II, but not widely available until the 1960s. Today, thousands of kidney patients owe their survival to this process. In the next few minutes, we'll take a look at dialysis, how it works, and who can benefit from it.
Joining us this evening, Dr. Leonard Stern and Dr. Jai Radhakrishnan. Both men are Assistant Professors of Clinical Medicine at the College of Physicians and Surgeons of Columbia University.
I'll start with you, Jai. To understand the role of dialysis in treating kidney disease, you have to be aware of the main function of the human kidney, to filter toxins and waste from the bloodstream. What criteria did doctors use to determine how much kidney function is required or is lost before they consider dialysis as a treatment option?
JAI RADHAKRISHNAN, MD: By trial and error, we came to know that we need about only 10% to 15% of kidney function. Certainly below 10%, most patients do feel the effects of not having adequate kidney function, and approximately thereabouts, we start the dialysis procedure.
LISA CLARK: Now, there are several types of dialysis -- peritoneal dialysis, and there's hemodialysis. For the purposes of this segment, we're going to focus on hemodialysis, which is a specialty of yours, so I'll ask you to begin with a brief explanation of the process. What happens when someone goes in for dialysis?
JAI RADHAKRISHNAN, MD: Hemodialysis essentially means cleaning the blood, and hemodialysis is a process whereby a machine which takes over part of the kidney function takes a large volume of blood from the patient, processes it the way the kidneys would normally process it, get rid of the waste and return the blood washed, in a manner of speaking, back to the patient. So when a patient who is supposed to be dialyzed comes to our unit, for example, you would sit in a chair, the nurse would put a needle into a special vein, which is surgically created, called a fistula. The two needles are connected to a machine, which then runs through the treatment time, which is about four hours. At the end of the treatment, the patient basically disconnects from the machine and is able to go home.
LISA CLARK: Len, is the fistula a permanent access site for hemodialysis?
LEONARD STERN, MD: Hopefully. The fistula is created by the surgeon in preparation for starting dialysis. These fistulas take a long time to mature, so the optimum management of a patient would be to create the fistula perhaps six months to a year before the patient requires treatment so that the vein would grow in size and would become large enough. The requirement of the fistula is that two needles are placed into the fistula repeatedly. The patients refer to it as a lifeline. After the needles are placed in and then removed, the fistula is reusable. An ordinary vein, when you place a needle into an ordinary vein, it collapses. It's no longer usable.
The fistulas have problems, though. In older patients, which are the majority of people that start dialysis, their veins are not good enough to create a fistula. Then they have to resort to artificial graft material, which is called Gore-Tex graft material, and the surgeons place these in position between arteries and veins, and these tend to have a limited lifespan. There are technical problems with them. They clot off frequently. But they also represent one form of access.
A third type of access is used as a temporary catheter, generally placed by either a surgeon or a radiologist in a position under the collarbone. There, the intent is as a bridge, to wait until one of these more permanent access develops. These bridge catheters -- or PermCaths, as they're called, or Tessio catheters -- are designed to allow us to provide dialysis treatments as a substitute for the fistula.
LISA CLARK: Jai, once you have the system set up, whatever the blood access is going to be, how long does the procedure take to have your body go through a dialysis cycle?
JAI RADHAKRISHNAN, MD: On average, each patient stays for between three and four hours at a time three times a week indefinitely.
LISA CLARK: What is the procedure like for the patient? When they come in, what happens for them?
JAI RADHAKRISHNAN, MD: Well, initially it takes a while for the body to get used to the procedure, so what the patient would notice is the needle stick. This can be minimized by using a local anesthetic, but a lot of times the patients just get used to the procedure and they don't need the anesthetic. Secondly, if the patient is not in a good situation as far as the heart goes, a lot of people have heart failure. Blood pressure may drop during the treatment and you may feel nauseous or you may have cramps or you may feel lightheaded, and this is minimized because the patients are monitored very carefully, and if the nurses do notice there's a problem, they'll immediately produce the amount of fluid being removed.
LISA CLARK: Now, that's one of the benefits of the hemodialysis process. You're in a center where there are doctors and nurses available.
JAI RADHAKRISHNAN, MD: Correct. That's a big advantage, because you essentially go there and you get taken care of. The other kind of dialysis is called home hemodialysis, where you have a significant other play nurse, essentially, so you're sitting there getting dialyzed by your significant other, who has to be specially trained, obviously. It is a complex procedure.
LISA CLARK: What sorts of patients would you recommend have hemodialysis as opposed to some of the other varieties that are available?
LEONARD STERN, MD: Well, the selection of patients is based in part on the other illnesses, so the sicker a patient and the more complicating the comorbid conditions, the more likely we are to advise a patient to be treated in a center. If a patient has multiple medical problems, treating at home might be difficult. People that are independent that can regulate their schedules and are organized actually do much better in home treatment. There they can organize their lives around their schedules.
LISA CLARK: Do they keep the machine there at home, or does someone bring it to them on a schedule for their hemodialysis?
LEONARD STERN, MD: It can be done both ways, but generally speaking the machine is kept at home. The water purification systems are organized at home. The options are that if a significant other is a partner, but some patients actually have insurance coverage where trained nurses can go to the patient's home to provide the treatment.
Patients that are treated in the center like the comfort of the center, and that's very important for many patients. Others don't like the rigor of the center, because you're given an appointment. That's your time. You have to come at that time. If you don't come at that time, your treatment can't go on.
LISA CLARK: I see. Jai, what are the medical advantages of hemodialysis?
JAI RADHAKRISHNAN, MD: The biggest advantage is that it's very efficient. You don't need to stay on the machine for a long period of time, so you're basically compressing two days' worth of kidney function into three or four hours.
LISA CLARK: I see.
JAI RADHAKRISHNAN, MD: The other advantage is that you can take out fluid and potassium and other toxins much faster, so if the patient's really sick and needs to be treated aggressively, hemodialysis is the way to go.
LISA CLARK: What are some of the disadvantages, though, of this?
JAI RADHAKRISHNAN, MD: That again relates to its efficiency, so a lot of people who are unstable from a blood pressure standpoint or whose hearts are not very strong, they may not tolerate the intensity of the procedure.
LEONARD STERN, MD: But these machine treatments can be modified and the therapy can be manipulated so that most patients are asymptomatic during the treatment. Our advantage of modern technology is that we can customize the therapy for a given patient to address their specific medical issues.
LISA CLARK: It also requires a very stringent diet, I understand?
JAI RADHAKRISHNAN, MD: It does, because -- think of it this way: You're doing two days' worth of kidney function in two or three hours, and for the balance, remainder of the time, you've got to be really strict because you get sick very quickly if you keep going on with an unregulated diet.
LISA CLARK: Thank you again, Dr. Jai Radhakrishnan, Dr. Leonard Stern. And thanks to all of you for joining us for this webcast. I'm Lisa Clark.
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