PHD out, NxStage in

After 20 months of suffering with the Aksys PHD, I am switching to the NxStage System One this week. The new modality has many benefits:

– It is portable. If you want to travel, a hurricane threatens, or there is a power outage, you can pop it in your car trunk, drive to another town, rent a cheap motel room or visit a friend, and dialyze. No more dependence on a clinic for back-up dialysis. You have the peace of mind that you will be able to dialyze, even in emergencies. You also are not tethered to one location within your home. You can dialyze in your bedroom one day, your living room the next day. This portability is helpful if you have to paint or redecorate a room.

– It only operates during dialysis. No more loud sounds or electricity bills which are $30 a month higher than before. No more alarms at 3:00 am. No more coming home to a machine which has been beeping for eight hours! No special electrical hook-ups. You just need a regular outlet.

– It doesn’t use 220 gallons of water a day like the PHD. It uses disposable bags of dialysate so your water bill doesn’t increase. These bags can be tossed in your regular municipal trash. Deliveries can be arranged monthly or every other week.

– The dialyzer and blood-tubing set are mounted on an easy-to-install, disposable cartridge which is changed prior to each use. This means the unit doesn’t have all of the parts operating all of the time, which causes most of the breakdowns in the PHD. The storage and trash requirements are slightly higher with NxStage, but not unreasonable.

– A repair technician won’t visit your home. In the very rare case where the System One fails, NxStage ships you a new unit overnight. The deliveryman puts the old unit in the same box and takes it back. Couldn’t be easier. The same procedure is used for annual system upgrades.

– No more drain-pipe back-ups or plumbing wall manifold. No more bloody water on the floor. The dialysate drains through a flexible, clear tube into the closest toilet or sink.

– Simple to operate. NxStage is used by nurses in acute-care units of hospitals and is very reliable. More patients already are dialyzing on the NxStage than the PHD. NxStage started home service four months ago. The Aksys PHD has been in homes for nearly four years.

The PHD may be the right choice for some patients. But NxStage certainly seems like it is the “next” generation in home hemo. So far the fluid removal has been good on NxStage and the treatment time has been comparable. I’m taking blood tests to check the clearance. I will report on my experiences in the months to come.

Debbie, Thanks for posting. Our center in Sayre is starting a program and leaning toward the Aksys I am doing all I can to get them to go to NxStage. I send them copies of post like yours. So thanks, for posting your comparison.

And don’t forget to visit my site…there’s plenty of info there to including my NxStage pics…

I welcome other patients to send their NxStage pics as well!.. :slight_smile:

http://www.dailyhemo.org
http://www.dailyhemo.com

congratulations Debby, on going to NxStage. it was due to your post that I chose to sell my shares of stock in Aksys.
I beleive you will be happier and more prosperous with NxStage.
it is easy to learn, setup a breeze, short treatments at your leisure.
be sure to let us know how it goes.

Has anyone experienced a difference with the “sterile” dialysate used with NxStage? I understand it is a step up from “ultra pure” dialysate used with some of the other machines.

Does anyone do flushing of the dialyzer with NxStage?

Does anyone use a Criltine with their NxStage txs?

The NxStage may be the next big thing in home hemo, but they will need to address some serious shortcomings, like the treatment time, for example.

The next generation is actually not that new in concept. Has anyone here ever heard of the Redy machine? You can see this one on the following website. As far as I know, this cartridge-loaded, transportable dialysis machine system dates back to the 1970’s.

http://renux.dmed.ed.ac.uk/EdREN/Unitbits/historyweb/HomeHD.html

Pierre

Wow, so many issues to discuss.

First, my clearance has been excellent, at least 2.5 times better than Medicare requires. I expect it will increase over time on NxStage. It was good on the PHD too.

Second, I feel and sleep better. My taste and other senses have improved. I no longer have to take naps after treatments. I believe some of this improvement is due to the fact that NxStage uses pure dialysate solution and no backflushes. The PHD uses backflushes of dialysate every 15 minutes. This was done to prevent the PHD from clotting up (which is not a problem with NxStage because the dialyzer and tubing are not reused). The PHD backflushes total 1.75 kilograms which is put into and taken out of your bloodstream during a 3-hour treatment. This affects your cardio system and can wear your out. I have much more energy with NxStage because I’m only receiving a small amount of saline (210cc) per treatment. The rinseback is less than PHD also – 200 instead of 400cc. The NxStage dialysate is in disposable plastic bags. The PHD dialysate is mixed daily from acid and bicarb and your filtered municipal water supply! You decide. NxStage was designed with the patient in mind; the PHD was designed by engineers to prevent it from breaking down.

Third, I dialyzed 3:00 hours on the PHD, which was 3:15 with backflushes. My treatment time on NxStage is 3:17 minutes. Those few minutes are well worth it because of all of the benefits of NxStage over the PHD. I could actually reduce the time on NxStage by increasing the blood flow, but I’m leaving it at a reasonable 400.

Finally, the PHD and System One are the only home modalities, other than traditional HD machines, which are being used in the U.S. If you know of anyone who is actually using a 1970s HD machine, let us know.

According to NxStage, I am the first person in the U.S. to switch from the Aksys PHD to the System One. And I’m glad I did. :smiley:

What determines how long a person must run on short, daily dialysis?

Re flushing the dialyzer, were you told that the only reason flushes are done on the PHD is to prevent clotting? Flushes also keep the dialyzer clear and improve clearance. Do you know why the flushes are hard on the cardiovascular system? How much saline is the dialyzer rinsed with at a time? Seems like a small amount.

Dear Jane:

Some nephrologists believe there is no such thing as too much dialysis. The length of time is determined by a variety of factors: patient’s weight, medical condition, other ailments, diet, clearance goals, lifestyle choices, type of modality, etc. Many home patients start out thinking they can get by with two hours a day only to learn that they need more time. The more you dialyze, the better you feel and the better the clearance, particularly phosphorous removal. In other parts of the world it is not uncommon for people to dialyze for 7 or 8 hours at a time.

The PHD uses the backflushes to prevent clotting and other problems during dialysis. The PHD goes through a loud and elaborate cleaning and disinfect process each day so it really doesn’t need backflushes to improve clearance. (The clearance on the PHD is good.) But the 15-minute backflushes were hard on me. I didn’t realize the extent of the impact until I started using NxStage. Various nurses and doctors have told me the constant backflushes can put stress on the cardio system. Nearly two liters of prepared dialysate pumped in and out of your system on a daily basis is not a small amount. Keep in mind that these backflushes, prime, and rinseback on the PHD are IN ADDITION to your daily fluid-removal goals! That is a lot of activity in your bloodstream, which does have an effect on your heart.

You should feel BETTER after dialysis, not WORSE! I feel much better after dialyzing on the NxStage System One.

The backflush on the PHD can be set to a fifteen, twenty or thirty minute interval or not at all and the backflush volume can be adjusted as well. I have my backflush interval set at 15 minutes and a backflush volume set at 150ml. This results in 600 ml of fluid being added to the circuit and to the hourly UF goal. By increasing the UF goal the backflush increase the movement of solutes across the membrane through the process of convection. With the backflush one should have a greater clearance of middle molecules than without the backflush due to convection. I have not seen any data on cardio stress due to the backflush process.

The PHD uses ultra pure dialysate which is a technical term not a marketing term. The PHD has two dialyzers that actually dialyze the incoming water to meet standards beyond what incenter water systems are required to meet in the US. The biggest question in my mind about the NxStage is the ultra low dialysate flow rates and the less robust blood tubing circuit it uses. I believe my provider will be offering the NxStage along with the PHD and the B Braun – it will be instructive to see how the three machines perform among the same user population.

From my center’s perspective the PHD addresses a large barrier to home hemo by allowing renters to do hemo at home because there are no adaptations required for it’s use. I saw the machine demonstrated and think it could be a good fit in my life because of it’s transportability – I could dialyze at work about half the time (the days when I’m chained to my desk) and I could see myself pushing it’s limits of transportability.

I am organizing a 6 week trip to South America and while there is probably all sorts of reasons why it couldn’t be done I think setting up treatments with the NxStage based out of S American centers would be a fantastic twist to what already promises to be a great trip. There is a documentary film maker here in Seattle that could be interested in using my trip to illustrate the state of health care in South America - the NxStage would allow me to dialyze in areas with out dialysis – that could be a compelling story but I guess it will have to wait for the machine to be more widely accepted.

Oooh, very interesting plan Bill, wish you luck on that.

Currently, have family from Mexico visitng, they’re very amazed at this little NxStage machine. My uncle quickly took his camera out and started taking snapshots of it. I told him, you know what uncle? Take those pics to the nearest dialysis clinics in Mexico, and am sure they’ll drop theirs jaws with excitement!.. :slight_smile:

Debby writes:
The PHD uses the backflushes to prevent clotting and other problems during dialysis. The PHD goes through a loud and elaborate cleaning and disinfect process each day so it really doesn’t need backflushes to improve clearance. (The clearance on the PHD is good.) But the 15-minute backflushes were hard on me. I didn’t realize the extent of the impact until I started using NxStage. Various nurses and doctors have told me the constant backflushes can put stress on the cardio system. Nearly two liters of prepared dialysate pumped in and out of your system on a daily basis is not a small amount. Keep in mind that these backflushes, prime, and rinseback on the PHD are IN ADDITION to your daily fluid-removal goals! That is a lot of activity in your bloodstream, which does have an effect on your heart.

Debby,
As Bill says in his post, flushing the dialyzer has another purpose of middle molecule clearance. I do understand what you mean about the flushes putting stress on your cardio system as I experienced pressure on my heart when doing manual flushes every 30 minutes by letting about 50 -100 ccs of saline through the dialyzer from saline bag… How many ccs of fluid went through your dialyzer ever 15 minutes? And were the flushes on PHD stronger than manual flushes like I described?

Bill write:
I have my backflush interval set at 15 minutes and a backflush volume set at 150ml. This results in 600 ml of fluid being added to the circuit and to the hourly UF goal.

What is the equivalent in cc’s?

Bill writes:
The biggest question in my mind about the NxStage is the ultra low dialysate flow rates and the less robust blood tubing circuit it uses.

Because?

mls are the same as ccs, I think. we should really ask Pierre. I think a ml is a milliliter or a 1,000th of a liter. A cc is a cubic centimeter of water meaning a square 1 centimeter in size would hold a ml of water. The metric system is suppose to be rational and based on some real world thing. I think the size of a kilometer is based on there being 10,000 kilometers between the equator and the pole. So a meter is based on kilometers and centimeters on meters…so milliliters are based on the circumference of the earth. I admit to being a fan of the metric system.

With regard to ultra low dialysate flow rates…I’d have to go back 9 years to when I first joined the online dialysis patient community, dialysis flow rate and what are ideal dialysis flow rates have been a constant topic if discussion. Jim Boag, a dialysis engineer and a leader of a dialysis standards and measures oversight board or authority posted about ideal rates and it came down to the ideal was twice the blood flow rate. Since Jim first posted this I have seen papers that describe how dialysate flow impacts dialysis adequacy, until the NStage came along I took it as a hard fast rule. I went to a NxStage presentation and heard the explanation that the slower flow allows the dialysate and the blood to dwell longer along the semipermiable membrane so it works. My theory is that sheer occurs with the difference between the flows and the increase efficiency is a function of sheer. So because the blood flow is faster then the dialysate flow it has the same impact as dialysate flow being faster than blood flow. If that is true then I would guess on the NxStage you’d want your blood flow to be twice your dialysate flow rate.

You have to think the folks who make the machines monitor this site. I for one would welcome an engineer (or the CEO) of the machine manufactures to post to this board. They would be under no obligation to respond to every question but I don’t know why they wouldn’t. Maybe check in on occasion and post to one thread…start one thread and present data and technical explanations. I would love to know the details. I’ve tried to understand the details for 10 years, no one understands this condition in totality, but it sure would be great if the manufactures could step up and talk to us as adults. I’d love to know what treatment choices the people who make our machine would make? And why?

A cc (cubic centimetre) is exactly the same as a ml. Nurses here, anyone over 40, still rountinely speak of cc’s when working with syringes. But it doesn’t matter as it’s the same thing.

I wasn’t too crazy about the forced conversion back in the mid 1970’s, but I like metric now. Everything is so simple and logical. I don’t know how it’s done in the U.S. in terms of weight relating to UF rate, but as a dialysis patient, I find it extremely handy that a kilogram is 1000 grams, and that 1000 grams of weight is exactly the same as 1000 ml of water.

Another aspect I like, perhaps from my background as a military officer, is that a person can easily visualize or see a kilometre on the ground, whereas a mile is sort of too long for that.

Pierre

Bill writes:
My theory is that sheer occurs with the difference between the flows and the increase efficiency is a function of sheer. So because the blood flow is faster then the dialysate flow it has the same impact as dialysate flow being faster than blood flow. If that is true then I would guess on the NxStage you’d want your blood flow to be twice your dialysate flow rate.

Can you explain this statement again? I run at a 350 pump speed on 3x dialysis. I have wondered what my blood pump speed and dialysate flow rate would be on NxStage.

Debby used Aksys and switched to NxStage. Has anyone using NxStage converted to the Aksys PHD? Don’t think so. I have seen the Aksys financial statements. You folks who are bashing NxStage should be careful. You may end up dialyzing with NxStage sooner than you think!

You have not told us about yourself mmiller, are you a patient mmiller? What bashing are you reffering to?

It’s just my therory why a dialysate flow lower than blood flow could work, just a guess, would love to see the analysis of an expert. I don’t think you would change your blood pump speed; your dialysate flow would depend on your run length and how much dialysate you started the run with…so it would depend. Something like a 100ml/minute though from what I’ve heard.

I think you should use whatever system works for you, I use the PHD system because I don’t want to mess with bags of saline and tubing changes every day. If the PHD dosen’t work for you then use what does. For me, I’ll keep the PHD.
John L