From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.med Subject: Re: Blood loss and kidney failure. Date: 20 Apr 1999 08:01:11 GMT In <7fg5kq$qpr$1@news5.svr.pol.co.uk> "Alan Bradbury" <norris@bradburya.freeserve.co.uk> writes: >I'm looking for a quick answer to a question. I'm a teacher in the UK and >a student asked a question that I didn't know the answer to. > >I understand why losing a large volume of blood would lower the output of >urine (lower blood pressure = less ultrafiltration) but why is the kidney >so susceptible to permanent damage following blood loss? Am I right in >thinking that it is the organ most likely to be permanently damaged? Why >is that? It's the organ most likely permanently damaged by medium amounts of blood loss. If you lose enough to lose all your blood pressure, then if you are revived the organ mostly likely permanently damaged is your brain. In slow loss, the body protects the brain at the expense of the other organs save heart and lungs, by squeezing blood into the heart/lung/brain circuit. Outside that, the kidney happens to be most sensitive to loss of blood volume. Why? Mostly because the kidney is set up to stop working entirely if you get very low pressures, in order to conserve fluid so you can get your pressure back up as fast as possible. That's hard on the kidney, because the only way to set it up to stop working entirely is to shut off blood flow to large parts of it, and these start to die. So it's mostly a connection and regulation problem. It's not that the kidney is more sensitive to lack of oxygen than other organs. Although the kidney does use more oxygen per gram than any organ (including your brain), it can get along without oxygen without dying for longer than many, even most, organs. In cold presevative solution, for example, a kidney can last several days without oxygen. A heart or a liver can only go a few hours. Your brain, when very cold and flushed of blood, has a duration time without oxygen or blood pressure surprisingly similar to heart and liver. At body temps, your brain is seriously damaged at 10 minutes (without very fancy resuscitation) and heart and liver less than an hour. Your kidneys can go longer than an hour after death and still (eventually) function at transplant (after a long period of recovery), though in practice nobody uses kidneys that "old." Steve Harris, M.D. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.life-extension,sci.med.nutrition Subject: Re: supplements to enhance kidney function Date: 26 Dec 1999 10:23:40 GMT In <83fdo1$cs6$1@bgtnsc01.worldnet.att.net> "John Gohde" <johnhgohde@worldnet.att.net> writes: > >eric <errock@rcn.com> wrote in message news:83ejik$80b$1@bob.news.rcn.net... > >> are there? > >water Your kidneys need a minimal amount of water to function, true enough. But the idea that giving them more than that will make them function better is about like suggesting that if you squeeze the trigger harder, the bullet will come out faster. The only function increase you get with drinking more, is the "function" of excreting excess water. But that's less a function, than lack of a function. Your kidneys do work mainly to RETAIN water after they filter out a fraction of your blood. If you drink too much, they simply relax and work less. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.life-extension,sci.med.nutrition Subject: Re: supplements to enhance kidney function Date: 27 Dec 1999 11:25:56 GMT In <844uj1$a90$1@nnrp1.deja.com> rjk3 <rjk3@my-deja.com> writes: > >In article <844qbc$n7l$1@nntp2.atl.mindspring.net>, > sbharris@ix.netcom.com(Steven B. Harris) wrote: >> In <83fdo1$cs6$1@bgtnsc01.worldnet.att.net> "John Gohde" >> <johnhgohde@worldnet.att.net> writes: >> > >> >eric <errock@rcn.com> wrote in message >> news:83ejik$80b$1@bob.news.rcn.net... >> > >> >> are there? >> > >> >water >> >> Your kidneys need a minimal amount of water to function, true >> enough. But the idea that giving them more than that will make them >> function better is about like suggesting that if you squeeze the >> trigger harder, the bullet will come out faster. The only function >> increase you get with drinking more, is the "function" of excreting >> excess water. But that's less a function, than lack of a function. >> Your kidneys do work mainly to RETAIN water after they filter out a >> fraction of your blood. If you drink too much, they simply relax and >> work less. >> > >Why then, when my cat suffered renal failure, did the vet have us >irrigate him? (Saline bag, needle in the skin of the neck....) Seemed >to keep him going a few more months. I understand this was the only >treatment for kidney failure in humans before dialysis machines. > >PS: Nice to see you here again. Cats are a bit of a special case, in that they suffer renal failure from several types of stone formation. Keeping their urine dilute just keeps the process from progressing, by keeping new stones from forming. Vets have a heck of a time with cats, since if their urine is too acidic, they get uric acid stones, and if it's too alkaline, they get struvite stones (due to their high ammonia production, a facet of their need to neutralize acids from proteins). So diets of cats with stones and renal problems get switched back and forth, also. Much of this doesn't apply to people, who get struvite stones only when infected with ammonia-producing bacteria (rare). From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.life-extension,sci.med.nutrition,alt.health, misc.health.alternative Subject: Re: Drink More Water (Re: supplements to enhance kidney function) Date: 27 Dec 1999 11:37:07 GMT In <845isl$8gp$1@bgtnsc02.worldnet.att.net> "John Gohde" <johnhgohde@worldnet.att.net> writes: > >Steven B. Harris <sbharris@ix.netcom.com> wrote ... > >> Your kidneys need a minimal amount of water to function, true >> enough. But the idea that giving them more than that will make them >> function better is about like suggesting that if you squeeze the >> trigger harder, the bullet will come out faster. The only function >> increase you get with drinking more, is the "function" of excreting >> excess water. > >You seem to be knowledgable on the subject of water. > >If a person eats a healthy plant based diet with plenty of fruit, how >many ounces of water / fluids should a person drink a day? I am >interested in a simple answer, NOT in starting a debate. The simple answer is that nobody knows. You have to make around 20 mL/kg of urine a day to get rid of wastes, but how much extra over this you need to drink, will depend on how much you have to sweat in the climate you're in and the work you do, and so on. And the correct dilution of urine for minimal chance of stone formation isn't known, either. Nor would this be expected to be simple, since, since it also depends on the amount of protein in the diet, amount of urate produced (a product of diet, genetics, hormonal status, etc), and so on. Around 50 mL/kg/day total fluid is generally what is given hospitalized patients with normal renal and heart function, at bedrest at continuous normal temp, and this produces urine which is about midrange in terms of dilution scale (from the most concentrated your kidneys can make, to the most dilute they can pass). >> If you drink too much, they simply relax and >> work less. > >Would you consider 96 or 100 ounces of water a day, excessive? I am >interested in a simple answer, NOT in starting a debate. No. It takes 2 or 3 times that, for months, to begin to impair your kidney's ability to concentrate urine. And even that recovers over time when water is restricted again, so no permanent damage is done. The worst things that happen from too much water, happen to people who don't get enough salt. But that won't happen in the range you give. From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.life-extension,sci.med.nutrition Subject: Re: supplements to enhance kidney function Date: 2 Jan 2000 04:38:52 GMT In <84ljd1$cil$1@nnrp1.deja.com> rjk3 <rjk3@my-deja.com> writes: > >In article <84c51v$4f0$1@nntp5.atl.mindspring.net>, > sbharris@ix.netcom.com(Steven B. Harris) wrote: >> In <847vim$7oq$1@nnrp1.deja.com> rjk3 <rjk3@my-deja.com> writes: >> > >> >In article <844pni$j8p$1@nntp8.atl.mindspring.net>, >> > sbharris@ix.netcom.com(Steven B. Harris) wrote: >> >> In <83ejik$80b$1@bob.news.rcn.net> "eric" <errock@rcn.com> writes: >> >> > >> >> >are there? >> >> >> >> No. A few things make you pee more, but getting rid of water is >> >> not your kidney's prime function. It's more of a side effect. >> >> Increasing it changes your main kidney functions not at all. >> >> >> >> >> > >> >I found that one function of the kidney is to produce EPO, which >> >signals the marrow to produce red blood cells; thus certain steroids >> >can be given in cases of kidney failure to stimulate EPO production >> >and prevent anemia. So maybe nandrolone enhances kidney function, but >> >don't try this at home. >> >> Androgen steroids stimulate marrow directly, not by increasing EPO. >> So your logic is bad to begin with. >> > >More precisely, the premise was wrong. Thank you for pointing that >out. There is no use in using the word "precisely," when you haven't used the language precisely to begin with. You did use the word "maybe." One assumes from that, that you are talking about an induction from stated facts, since if you weren't certain you had your facts right, you should have used that "maybe" somewhere before you did. So what was the function of the word in your sentence? You weren't trying to say that nadrolone causes an increase in one function of the kidneys (making EPO) so perhaps it causes an increase in others, as well? If that wasn't your point, what was your point? From: sbharris@ix.netcom.com(Steven B. Harris) Newsgroups: sci.life-extension,sci.med.nutrition Subject: Re: supplements to enhance kidney function Date: 4 Jan 2000 08:10:24 GMT In <20000102122158.08015.00000584@ng-ft1.aol.com> darlingdemoniac@aol.combiteme (Darling Demoniac) writes: >Hi, >My father is on dialysis, what sort of supplements would be helpful for him, if >any? > >-MicHeLLe >Http://darlingdemoniac.com >Http://www.twistedfool.com B vitamins are dialyzed out. I once actually saw a lady on dialysis who'd stopped taking her vitamins. She was Spanish and did a lot of home cooking, specializing in her own hand-made cornmeal tamales. Yum. Alas, that meant lots of unfortified corn flour calories. She came to me complaining that her arms were turning black in the Summer sun, a tan too dark. And she was right. Skin was dry as well. She had pelagra! Cleared up nicely on niacinamide. Nephrologists know about this, though, and all renal patients are already supposed to be taking B vitamin supplements, at minimum. A few, no doubt, are noncompliant. |
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