More Articles About Nocturnal Home Hemodialysis

Frequently Asked Questions about Nocturnal Home Hemodialysis

February 2000

The following FAQs were prepared by the staff of the Nocturnal Home Hemodialysis (NHHD) program in Toronto.

Patients have been involved in the Toronto program since 1994. Interest has been expressed by nephrologists from as far away as Australia, where a pilot program is scheduled to begin shortly.

What Is Nocturnal Home Hemodialysis?

It is a form of hemodialysis that can be done at home by either the patient, mate or other family member. It is done at night, while the patient is asleep. It is done six or seven nights a week. The length of the dialysis varies. It can last as long as the patient wants to sleep, anywhere from five to 12 hours, with eight hours being the average. The dialysis machine can be monitored by trained hospital staff by telephone modem or Internet. The machine will occasionally alert patients to any problems. (Most problems are minor and usually require pressing a "reset" button.) However, if the patient does not respond within a reasonable period, the hospital monitor will contact them by phone.

Where And When Was NHHD Started?

Nocturnal hemodialysis was started by Dr. Robert Uldall at the Wellesley Hospital in Toronto in 1994. After Dr. Uldall’s death in 1995, Dr. Andreas Pierratos took over as chief nephrologist in the project. Because of general restructuring in 1998, the program now is run out of Humber River Regional Hospital.

How Many Patients Have Tried Nocturnal Hemodialysis?

Almost 40 patients have been trained to take part in the Toronto project and the Ontario provincial government has authorized funds to almost double the number of participants. As of September 1999, a total of 830 months of patient experience had been documented. One of the first patients to participate has dialyzed almost every night for the last 5 ˝ years, choosing not to take the normal one night a week off. To this day, he is gainfully employed and has had no major medical problems.

Why Is Nocturnal Hemodialysis Better?

Because it is long and frequent, Nocturnal Hemodialysis can offer a very high dose of dialysis. When it comes to toxins like urea, NHHD can offer results as effective as normal kidneys. Generally, all symptoms associated with kidney failure improve or disappear. Patients report feeling more energetic, having increased stamina, improved appetites and less bouts of nausea. There are fewer complaints of other symptoms like itchy or dry skin or "restless leg syndrome."

Many patients have also found their need for medications to combat such things as high blood pressure has diminished or ended altogether. Other patients diagnosed with sleeping disorders (i.e. sleep apnea) no longer reported those problems.

As one patient said:

"Conventional hemodialysis is like riding a Volkswagen on a dirt road, while Nocturnal Hemodialysis is like riding a Rolls on a freshly paved surface."

What Are Some Of The Other Benefits?

Probably one of the most welcome changes is the lifting of almost all dietary restrictions. Removal of phosphate has been so much better that many patients stop taking calcium pills and are, in fact, encouraged to eat more phosphate in their food. Restrictions on dairy products, nuts and colas are lifted. Since dialysis is done nightly, there is no limit to the amount of water patients can drink or even the amount of salt they eat. In addition, the amount of EPO necessary decreases in most patients and some come off the blood-producing drug altogether.

Do I Need A Special Kind Of Dialysis Machine For NHHD?

No. All dialysis machines can be used, but can be modified for remote monitoring via modem or Internet connection. Occasionally, the dialysis machine will sound an alarm if it detects uneven levels in the arterial or venous chambers. The are usually minor problems caused by a kink in the lines or some such. They are easily corrected by simply pushing a "reset" button. However, if the patient does not respond in a reasonable length of time, the monitor can contact the patient by phone. The remote monitoring is not a critical part of the method. Although useful, it is not a life-saving element and a few centers have chosen not to monitor their patients.

What About Dialysis Vascular Access? Do I Have To Use A Central Venous Catheter?

No, any dialysis access is good for NHHD. For the first four years of the project only central venous catheters were used for fear of disconnection of dialysis needles during the night. For the last year, almost all patients have been equipped with fistulas and less often with grafts. Catheters are still used and in many patients can be long-term accesses.

Is Using A Fistula Safe? What About Cannulation Pain, Especially Since Dialysis Is Virtually Every Night?

Instead of steel dialysis needles, patients use plastic cannulas, which resemble the cannulas used for intravenous infusions. They are longer and soft. Therefore, there is only a minimal risk of infiltration of the fistula during dialysis. And because of their length, the chance of disconnection is remote. Special taping further ensures stability.

What Is The "Buttonhole" Technique Of Fistula Cannulation And What Are The Advantages?

The buttonhole technique of cannulation involves inserting the needle (or cannula, as in the case of Nocturnal Hemodialysis) through exactly the same hole every time. This makes success of the cannulation predictable, and after a few insertions there is no pain involved. Although cannulating in the same area of the fistula can be a cause for fistula aneurysms, there is some evidence that the "buttonhole" technique involving insertion in exactly the same hole prolongs the life of the fistula. Results over the last three years have been excellent.

What About The "Single-Needle" System?

The single-needle system, as the name suggests, requires only one needle to perform hemodialysis. The blood-flow through the needle is continuously reversed. This method is not popular in hemodialysis units because it can’t deliver high blood flow and therefore results in poor dialysis. In the case of Nocturnal Dialysis, with its long duration and high frequency, high blood flow is not necessary. Therefore, single-needle dialysis is excellent for Nocturnal Dialysis.

What About Catheters?

Central dialysis catheters provide adequate flow for Nocturnal Dialysis, but often is inadequate for conventional hemodialysis. The use of catheters, though, has been associated with a higher incidence of infections or clotting. Usually, these conditions can be easily controlled and the risk of a severe infection is small. Patients are most often treated with an anticoagulant that can pose the risk of excessive bleeding.

What About Problems Sleeping While Connected To A Machine?

Despite some noise from the dialysis machine and water system, most patients had no trouble sleeping after the first few nights. As mentioned earlier, sleep studies show patients with sleep apnea (disturbed sleeping with snoring) actually improved. Spouses also reported getting used to the systems background sounds.

Will Nocturnal Dialysis Help Me Get Back To Work?

Many NHHD patients have returned to work full time. Not only did they feel better, but had more free time for family and other activities since they dialyzed during the night.

How Long Does The Training Last?

Training usually lasts six weeks. Patients (and sometimes their spouses) report to the training unit five days a week for five or six hours daily. The last week of training includes sleeping at the hospital overnight to put your learning to the test.

How Often Do I Have To Go To The Hospital After Training?

Once the home procedure is running smoothly, patients are required to attend an outpatient clinic every two months. Blood tests are usually contributed monthly and nurses and technicians are always available for telephone consultation.

Are Diabetics Candidates For Nocturnal Dialysis?

It is estimated that about 40-per-cent of all dialysis patients could be candidates for NHHD, including diabetics. In fact, diabetic patients can benefit even more from Nocturnal Dialysis.

Can Patients With Heart Disease Go On Nocturnal Dialysis?

Yes. In fact, the more severe the disease, the more the patient benefits from Nocturnal Hemodialysis.

What About Risks?

The question of potential "over-dialysis" has been raised. Is it possible that too much dialysis can remove "useful" chemicals? No problem yet encountered has not been able to be easily corrected.

Is There A Catch?

Training for Nocturnal Hemodialysis is reasonably complicated and not all patients feel comfortable going through the learning process. The industry is working to produce more "user friendly" machines to expand the user pool. An important advantage is that Nocturnal Hemodialysis can be performed by the patients, with no required assistance from spouse or mate.

What About The Cost?

Although more detailed studies are under way, figures so far indicate that Nocturnal Hemodialysis - at least in Canada - is less costly than conventional in-center dialysis.

Why Is Nocturnal Dialysis Not Used More Widely?

Some pilot programs have been started in other Canadian centers, as well as in the U.S. and Australia. As with all medical advancements, more knowledge is needed by nephrologists, nurses, administrators and patients.

What Other Options Are Being Investigated?

There is evidence that dialyzing between two and 2 ˝ hours daily can offer significant advantages over conventional hemodialysis (i.e. three four-hour sessions weekly). Participants reported improved quality of life. Blood pressure can be better controlled and the need for EPO usually decreases. On the other hand, the control of phosphate and some other laboratory tests are not as good as with Nocturnal Dialysis and the patients’ diet is not as free.


(Michael Williams, moderator of our Forum for Patient Centered Care, has been with the Toronto program for more than two years. Additional questions may be directed to him through the forum or directly at

More Articles About Nocturnal Home Hemodialysis
RenalWEB Home Page