What is the big deal about Dry Weight in Dialysis?

My friend Max often says to me, “You should write about dry weight. It’s a great way to track your dialysis and your health.” I used to think that it was a bit more complex than that, but over the last month or so I have come around.

Dry weight is the weight you should be if you had normal kidneys and you just had your morning pee. So in dialysis, it’s the weight you aim to be just after you come off the machine.

When you first hook up to the machine, you will often be carrying extra fluid, which makes your heart work harder and drives up your blood pressure (BP). The more fluid, the higher the BP. The more damage you are doing to your heart.

During the run, the machine not only cleans your blood, it also removes the extra fluid (the amount it takes off is usually agreed between you and your nurse) When you come off the machine, if you are at your correct dry weight, and are otherwise healthy, you will also have good BP (somewhere near 120/70).

It’s a pretty simple equation.

But sometimes it takes a while to sink in, especially if you are concentrating on something else. I had a virus over the last month. I couldn’t exercise and unconsciously ate less. After just a few days, my BP was very high at the start of the run and it stayed high. I was convinced that it was the virus working some BP mischief. I was sure my dry weight hadn’t changed. But when I finally shook off the virus, my BP was still too high. I discussed this with Chris (Unit Manager) and as an experiment, took my base weight down a kilo (from 78kg to77kg). My BP went down, though not to my 120/70 ideal. The next day, I moved my base weight down another .5kg to 76.5kg. Success! My dry weight BP was 121/70. I had lost 1.5 kg during the month and I had masked the loss by drinking more and not taking enough off.

It all seems pretty obvious now: right dry weight = right blood pressure. I was convinced it wasn’t that simple, but it was.

From now on, I will do like Max does: quietly monitor my BP and dry weight over each run. Keep an open mind. If my BP is high, I’ll, experiment with a lower dry weight. If my BP is low, I’ll add a .5kg; I may have gained dry weight.

Dry weight is of course not the only answer to a healthy blood pressure and a healthy heart. But it is often the answer, it’s simple to monitor and it’s DIY: no doctors needed.

What’s your dry weight (this week)?

How many people are on Dialysis?

In your state?  In your country? In the world? Let’s go for the big one.  How many BigD members are there on our fair planet?

First, some definitions:  the term for anyone receiving any kind of therapy for End Stage Renal Failure is called Renal Replacement Therapy or RRT. So, all of us who have functioning kidney transplants, or on haemodialysis or peritoneal dialysis are on RRT. The best way to work out how many people are actually on RRT is to look at the countries that measure and analyse their RRT numbers and extrapolate.

For example, in Australia and NZ, the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) collects a wide range of statistics which relate to the outcomes of treatment of those with end stage renal failure. They produce a detailed report each year broken down by age and sex (a common problem) and anything else you can imagine. Part of their summary states:

• In Australia, there were 16,751 people (797 per million) receiving renal replacement therapy (RRT) at 31st December 2007. Of these, 7,109 (338 per million) had a functioning kidney transplant and 9,642 (459 per million) received dialysis treatment.
• In New Zealand, there were 3,353 people (793 per million) receiving renal replacement therapy (RRT) at 31st December 2007. Of these, 1,289 (305 per million) had a functioning kidney transplant, and 2,064 (488 per million) received dialysis treatment.

In Canada, the Canadian Institute for Health Information provides a range of aggregate-level data on dialysis and transplants. However, the day I chose to check it out, it was down “upgrading content and functionality”.  The most recent report I could find was dated 2004.  However I suspect that the numbers are similar to those in Australia.

In the US, the National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC), which is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), which in turn is part of the National Institutes of Health of the U.S. Department of Health and Human Services, produces an excellent annual report. From the summary page:

• Prevalence (2006): 506,256 U.S. residents were under (RRT) treatment as of the end of the calendar year
• Cost for the ESRD program (2006): $33.61 billion in public and private spending
• Dialysis treatment (2006): 354,754 U.S. residents with ESRD received dialysis:

• In-center hemodialysis: 325,299
• Home hemodialysis: 2,455
• Peritoneal dialysis: 26,114

In the UK, the UK Renal Registry produces a report each year. From the summary:

• There were 45,484 adult patients receiving RRT on 31/12/2007. The population prevalence for adults was 746 per million population per year (pmp) with an annual increase in prevalence of approximately 5% per annum.
• The most common treatment modality was transplantation (21,196 – 46.6%), closely followed by centre-based HD (19,149 – 42.1%) in either the primary centre (25.2%) or the satellite unit (16.9%). The HD population has continued to expand, and the PD population to contract.

For all European RRT data, the European Renal Association – European Dialysis and Transplant Association (ERA -EDTA) produces an excellent annual report.  Roughly, there are approximately 260,000 people on dialysis and there were about 8000 transplants conducted throughout Europe in 2007.  See the above report for by country and demographic listings.

(Note the low number of transplants in Australia and New Zealand compared to most other countries.  This is due to a very poor level of organ donation in ANZ.  They have an Opt-in system (you must formally nominate to be an organ donor), where many other countries have an Opt-out system (where you must formally nominate NOT to be an organ donor).  This and a secret fear that “they might take me before I”m dead” keeps the transplant wait time at 5 – 10 years.)

After this it gets a little rubbery. Time for calculations. If you look at the average per million people (pmp) figures for the above countries, and you use this to extrapolate for countries in Asia, Africa, Eastern Europe, South America and the Middle East, etc. (it’s done very badly here, but it’s a good list of countries) my best estimate for the number of people on the Big D is between 4 and 5 million people.

So united we could form a small country, but it would need a serious health care budget.

What does dialysis and a kidney transplant cost?

I had an email through the week from a thirty-something mum looking down the barrel of kidney failure and dialysis over the next couple of years. In addition to coming to terms with the illness that is causing her problems, she needed some practical information about the finances of treatment.

“What is the cost !! of both Dialysis and a transplant (should I be lucky enough)?”

Like everything else that happens as we move down this path, we tend to learn about it when we need to know, but with the BigD, it’s not easy to find answers.

The Costs of Dialysis

In the private system, each health fund tends to negotiate a payment per haemodialysis treatment with each dialysis centre or company. For example, health fund A may have agreed to pay Diaverum centres $220 per session, while health fund B may pay Baxter $190 per session. As long as you have the cover, you get the treatment. However, many health insurers limit the number of treatments to three per week. Others will allow more, but only on your doctor’s recommendation/request.

The best thing to do is to contact the centre(s) you may be attending and ask them. Then confirm your cover, etc with your health fund. In each case, you are not usually out of pocket. It is also worthwhile asking about the extras that the centre provides (food, TV, internet, etc).

Obviously, if you go to a satellite centre associated with a public hospital, treatment is free. Or if you choose to dialyse at home (or you live far away from dialysis centres) the government covers the costs, including the machine, its installation, plumbing, etc and your training.

The Cost of a Kidney Transplant

With kidney transplants, costs vary per country, and are in the tens of thousands of dollars (or pounds or rand, etc.) But in most cases they are done at public hospitals and the cost is covered by the national government. In the US, kidney transplants are covered by Medicare; in the UK by the National Health Service, in Australia by Medicare, etc. The cost is roughly equivalent to the cost of dialysis for a year, so a successful transplant is a good deal for health authorities.

You can also have a transplant via the private system is you have the coverage (or the money).

I had mine at a public hospital, The Austin Hospital in Heidelberg, Melbourne. I much prefer the public system, and not just because of the price. In the public system, the support network is wide. You and your transplant team can tap into the latest skills and experience from transplant teams around the country and the world. Medical staff are available onsite most of the time and the higher volume of transplants means they have seen most problems before. My transplant teams stopped at nothing in getting my transplants working, and the care was excellent.

Also, many public hospitals are happy for you to elect to be a private patient within the public system, in which case you get your choice of doctor with the added benefits listed above and costs are usually rebate only.

(So, in most countries, it’s not the cost that’s the problem, rather the availability of donor kidneys – but that’s another post.)

Next week: some of the stats of the BigD: how many, what demographics, life expectancy, etc.

Hello ‘Wearable Kidney’; Goodbye Dialysis Machine?

August was a big month for the BigD community. Early in the month, Dr. Christopher Chan, medical director of Home Hemodialysis at Toronto General Hospital’s University Health Network announced the results of a study of 1,239 patients over 12 years that showed that kidney patients who received home hemodialysis treatments lived as long as those who got kidney transplants from donors.

As has been found before, the study confirms that the more often the dialysis, the better the cardio-vascular health (weight is stable, which reduces impact on the heart) and quality of life.

Building on this desirability of regular or even continuous dialysis came a breakthrough on August 20: the Wearable Artificial Kidney. The press release, titled “HELLO ‘WEARABLE KIDNEY,’ GOODBYE DIALYSIS MACHINE” states:

“Our vision of a technological breakthrough has materialized in the form of a Wearable Artificial Kidney, which provides continuous dialysis 24 hours a day, seven days a week,” says Victor Gura, MD (David Geffen School of Medicine at UCLA).

The device—essentially a miniaturized dialysis machine, worn as a belt—weighs about 10 pounds (4.5kg) and is powered by two nine-volt batteries. Because patients don’t need to be hooked up to a full-size dialysis machine, they are free to walk, work, or sleep while undergoing continuous, gentle dialysis that more closely approximates normal kidney function.

See the belt and how it is worn:

Anyone working in construction will feel quite at home.

Looks like the access is via a PermaCath (you can just see the tape).

Such a device could lead to a “paradigm change” in the treatment of dialysis patients. Despite enduring long hours on dialysis every week—with major limitations in activities, diet, and other areas of life—dialysis patients face high rates of hospitalization and death. The U.S. dialysis population currently exceeds 400,000, with costs of over $30 billion per year. “We believe that the Wearable Artificial Kidney will not only reduce the mortality and misery of dialysis patients, but will also result in significant reduction in the cost of providing viable health care,” says Gura.

The Wearable Artificial Kidney is successful in preliminary tests, including two studies in dialysis patients. The new study provides important information on the technical details that made these promising results possible.

“However, the long-term effect of this technology on the well-being of dialysis patients must be demonstrated in much-needed clinical trials,” adds Gura. “Although successful, this is but one additional step on a long road still ahead of us to bring about a much-needed change in the lives of this population.”

The WAK uses several innovations, including a pulse pumps that operate quite differently from the current roller pump technology. Where possible they have used standard off-the-shelf components.

A little fuzzy, but readable on the Paper, which also has a blow-by-blow description of operation.

Here’s the schematic from the paper.

Still, the results are very encouraging. It looks a little clunky now, but so did the first TV, computer and mobile phone.

Obviously there are still many questions: What kind of access would enable continuous, 24/7 use? What would it cost (the current estimate is “less than the current machines” and the monthly consumables ‘below the current sums spent”. How would this disruptive technology impact the current approach?

From a personal level: Is it the Can I get involved in a trial? When can I have one?

For more information on “Technical Breakthroughs in the Wearable Artificial Kidney (WAK),” the article is available online at the Clinical Journal of the American Society of Nephrology for a mere US$22.  The Press Release is here.