Nocturnal dialysis is not really a new concept. When my mother started on dialysis in 1967, eight-hour treatments three times a week were normal. In those days, a large percentage of people on dialysis did their treatments at home and dialyzed overnight.
Renewed Interest
The renewed interest in this modality is the result of several recent studies on improving the quality of dialysis. These studies have demonstrated very well that nocturnal dialysis patients are doing much better than they have done on standard in-center dialysis.
The dialysis industry is also beginning to pay a lot of attention to home dialysis and is starting to put a lot of money into developing better machines and methods to make it easier for patients to take care of themselves at home. The U.S. Food and Drug Administration has even identified home dialysis machines as a new category of machines and has a special procedure that companies go through to demonstrate that their product will work for the home patient.
Determining Quality of Care
There are several different ways in which dialysis units and Medicare determine how well patients are doing on dialysis. They look at things like how much dialysis a patient receives, how well bone disease is managed, and how well blood pressure is controlled, among other things.
By every measure, patients who are on nightly nocturnal dialysis do better. They feel better, take less medication, spend less time in the hospital, and, overall, it costs less to provide care for them. However, while this treatment modality may be for many patients, it may not be for some, including elderly people with limited mobility who may be living at home alone.
Let's take a look at some of the ways dialysis care is measured:
"Adequacy of Dialysis"
What is "adequacy of dialysis?" This is a measure of how much dialysis a patient receives based on how much blood urea nitrogen (BUN)--a protein waste product--is removed from that patient. As you might imagine, when patients are dialyzed longer and more often, more BUN is removed.
In 1975, Carl Kjellstrand, MD, a pioneering nephrologist and a foremost proponent of more frequent dialysis treatments, developed what he called the "Un-Physiology Hypothesis," which said, "We hold this truth to be self-evident in dialysis: Normal chemistries and physiology are better than abnormal... a lot better!"
The less time patients go between dialysis treatments, the less BUN will get built up in their blood. If the dialysis treatment is long enough, the BUN can be removed slowly so the body doesn't go through rapid changes, and the treatment is much easier tolerated by the patient.
"Preventing Bone Disease"
It is very hard to prevent dialysis patients from having problems with bone disease when they are using standard in-center dialysis treatments. For these individuals, following the renal diet that helps minimize bone disease is one of the worst parts about having kidney failure.
It is very difficult to understand renal bone disease, so I will describe the process that breaks down bones in basic terms:
When the phosphorus level in the blood gets too high, it makes the calcium "precipitate out" (crystallize out) of solution. In other words, it turns back into a solid.
The now solid calcium gets stuck in soft tissue, such as the heart muscle. When that happens, the heart will become rigid and brittle, causing it not to pump as well.
When the calcium level drops because it has crystallized out, the body pulls calcium out of the bones so that there will be enough in the blood.
As long as there is too much phosphorus in the blood, there is a never-ending cycle of pulling calcium out of the bones (where you need it) and depositing it into the heart (where it is harmful to you). This ends up causing weak bones as well as hardening of the arteries and the heart muscle.
Only on long nocturnal dialysis treatments can patients stay on the machine long enough to get the phosphorus out of all their body cells. In fact, not only do patients on nocturnal dialysis no longer have to take phosphate binders, they get to eat as much cheese and drink as much milk as they want! Most patients on nocturnal dialysis don't follow a special renal diet at all and they can eat pretty much anything they want.
Controlling Blood Pressure
Due to the more frequent nature of nightly nocturnal dialysis, there is much less fluid to remove from the patient, and the heart doesn't have to work as hard. And just as important: because the fluid is removed over a longer treatment, it is much gentler, and patients do not have the same level of cramps and drops in blood pressure (hypotension) during dialysis.
For example, on standard three-times-a-week dialysis, if patients drink two liters a day, they would need to remove four liters during a four-hour treatment, or one liter per hour of dialysis. That is a very dramatic change for the body to go through! On the other hand, a nightly nocturnal patient has only two liters to remove in eight hours, or just 1/4 of a liter per hour of dialysis.
The studies of nightly nocturnal dialysis show that these patients have much better control of their blood pressure, and take fewer blood pressure medications too!
No More Washed Out Feeling
Patients often report that they feel bad before a dialysis treatment. This is because they have too much fluid and waste products in their bodies. However, even after a dialysis treatment, most patients tend to feel "washed out" for several hours. They feel bad because of how fast the dialysis removes the wastes and fluid. They mostly only feel good the day after a dialysis treatment.
In one of the studies, patients were asked how long it took for them to "feel better" after a dialysis treatment. On average, they said it took about five hours! That is a long time. After being on nightly nocturnal dialysis, these same patients were asked the same question. They responded that it took less than 20 minutes to feel better after dialysis! That is really one of the most important things I have found in all of the things I have read about nocturnal dialysis: Patients feel better!
It seems that Dr. Kjellstrand knew exactly what he was talking about more than 30 years ago when he wrote the Un-Physiology Hypothesis. More dialysis is proving to be much better than less dialysis!
About the Author
Jim Curtis, CHT, CCHT, is a former President of the National Association of Nephrology Technicians/Technologists. He is the managing partner of Jim Curtis & Associates, LLC, in Portland, OR.