Wednesday, March 11, 2009

The trouble with haemodialysis

Apparently, le Welsh was quite excited by the thought that my post "The Trouble with HD" might be about haemodialysis, and rather disappointed to find it was actually about High Definition television. Although quite why I would post about such a thing is beyond me, but still... Anyway, not wanting to disappoint, here is my follow up.

The trouble with haemodialysis, at least from a blogging perspective, is that I don't really know quite what it is. Still, I do know the dialysis is something used for kidney failure, and that the kidneys are responsible for flushing toxins from our systems. Also, the prefix "haemo" implies blood, so I'll surmise that it's a process by which the blood is cleaned of toxins. Probably with an exciting machine that goes, "bing!" every so often.

A quick Google of the topic reveals that this surmise is broadly correct. Although wikipedia fails to indicate exactly what noise the exciting machine makes. I feel I shall have to investigate further.

It seems to me that the other fundamental problem with haemodialysis is that it actually does nothing to solve the problem. It does nothing to repair the failed kidney and so, fundamentally, is only of use to keep the patient alive until a replacement organ becomes available.

Clearly, what we need is some means to repair or replace a damaged kidney, preferably without being bound by the limited supply of donor organs. I can see three (maybe four) possible ways to do this:


  • It might theoretically be possible to engineer some nanotech devices to enter a failed kidney, fix the damage, clear out the toxins, and therefore bring it back to health. (The possible fourth solution would be to do much the same thing with some application of stem cells. However, in reality I suspect neither the nanotech nor the stem cell solution would work in isolation. A combination of the two, perhaps...)
  • We could perhaps construct a mechanical artifical kidney, in the same way we almost have a functional artifical heart. Essentially, this would be a very small-scale dialysis machine (probably without the exciting "bing!" sound, or whatever). It is likely that this would also be a short-term solution until a permanent solution could be developed, but it would probably be a step forward at least. I wouldn't be surprised to see this being the first solution implemented, and wouldn't be terribly surprised to see them in common usage by the end of the next decade.
  • Finally, there exists the possibility of using stem cells to clone a new kidney from the patient's own tissues. This would dodge the issues of the shortage of donor organs, and remove the risk of organ rejection, both of which would be a good thing. And, as scientists seem to have found techniques to reprogram 'adult' stem cells to work like embrionic stem cells, the ethical concerns here need no longer apply, which is nice.


So, I think there is cause for hope. Of course, everything I have just written could be a load of utter tosh. Five minutes of research on Google while waiting for an email is hardly a substitute for actual expertise.

2 comments:

Amy said...

Ah, now this I understand! :) Thank you! I like your points about possible 'cures' for kidney failure very much indeed but thought I would throw in that it is actually possible to correct some forms/degrees of renal disfunction already but the biggest challenge in this is that people will rarely display or experience any symptoms until the kidney function is reduced to just 30%. At 10% renal replacement therapy (dialysis or transplant) is required. Unfortunately there are many causes of renal failure which cannot be reversed which is where dialysis comes in.
Another common, and unfortunate, misconception is that people on dialysis "wait" for a new kidney, and that when they get one it will last forever. Sadly, many people will have co-morbidities which preclude them from being on a transplant list and certain factors such as having had blood transfusions during the course of their treatment can make people less likely to be compatible with a donor kidney. The average life of a donated kidney (if it is accepted by the body) is only somewhere around ten to fifteen years, I believe. I very much like the idea of some kind of portable dialysis device (perhaps like the insulin pumps now used by diabetics, which remain in constant contact with the patient's skin). Many people don't know about peritoneal dialysis, which is often a continuous process which allows the person to carry out a relatively "normal" daily life as it is not time restrictive like haemodialysis. It can often be done via a machine overnight, which is not so restrictive. HD however, is harsher on the cardiovascular system and I wonder how a portable device would get round this. Hmm. I hope you liked investigating my kind of HD; I think this might be my longest blog comment ever :)

Amy said...

Ah! I forgot to put in that if the kidney failure is acute then dialysis mght be said to "cure" the problem I suppose, if there is not a permanent injury which means renal replacement will always be necessary.
Also, the machines don't tend to bing, but beep. Sometimes they make a sort of groaning noise too (there are two types of machine and one beeps, one groans). Both noises are, as I'm sure you can imagine, very annoying.