How long does it take for water to be processed by kidneys?

In My Humble Opinion
1

So, I’ve been passing a stone for the last 10 days or so, which is notoriously painful (In fact I correctly guessed I was passing a stone thanks to the “what is the worst pain you felt” threads on the SDMB).

One way to reduce pain in theory is to reduce water intake, in order to limit the pressure build up in the bloked or semi-blocked kidney and I’ve been trying that for the last 24 hours or so, at first glance with some success. However, pain is highly variable in frequency, duration and intensity. So, in order to properly test this, I need to have some clue about how long it takes from the moment when I eat food (obviously containing more or less water) or just drink water to the moment when my kidney is actively producing urine.

I guess it might be that it’s highly variable too but your answers may help me retain my mental sanity. Thanks in advance.
(By the way, any advice about how to reduce pain felt while passing a stone is welcome too)
ETA : on second thought, since I didn’t make it clear in my OP and people will surely mention it : I did seek medical care, went to the hospital, saw my doctor, I’m taking drugs, etc…

2

IMO, this is a bad idea. If anything, you want to flush the stone out. Further, by limiting your fluid intake, not only will the stone not get flushed out, but any bacteria ‘trapped’ in or by the stone, will also tend not to get flushed out. IOW, a situation which may promote a urinary tract infection.

In terms of “how long for water to be processed by the kidneys”, my unequivocal answer is that: it depends (seriously; it depends on, among other things, your state of hydration which, if you limit fluids, may be low and, thus, lead to less urine being formed . . . with potential consequences as above).

All, again, IMHO.

3

Moderator Action

The OP contains both a factual question and a request for medical advice. Because of the latter I am going to move this thread over to IMHO so that folks can give their opinions on the medical issue. The factual aspect of the question may still be answered there as well.

Moving thread from General Questions to In My Humble Opinion.

4

Dropping in to second KarlGauss’s advice. Push fluids!!.

Hope you’re also on an alpha blocker like tamsulosin to help ease passage, and have some decent analgesics available.

5

Yes, this is exactly the opposite of the conventional wisdom, which is to increase water consumption during a kidney stone attack, for the reasons KarlGauss mentions.

The less water you consume, the higher the concentration of the solutes (salts and minerals, waste products, etc.) in your blood. When the concentration of the solutes in your blood increases, your body makes more antidiuretic hormone. This makes your kidneys put more of the water from the filtered blood back into your bloodstream, and less into your urine. This concentrates the urine with an unusually high level of solutes, including the salts and minerals which most commonly make up kidney stones. This increases the risk of more kidney stones or larger kidney stones, and decreases the frequency of urination, leaving the urine in your bladder longer, which can lead to urinary tract infections.

Drink your water. Your body is always making urine, so “when will it process this water” is really not very possible to answer. The urine is made all the time, from the blood, and the blood is always taking in new water from the digestive system - most of it from the small and large intestines, but some from the mucus membranes of your mouth - your spit turns into your urine, if you trace it far enough.

If you want some gentle symptom relief, I’ve had good luck with cornsilk tea. Cornsilk is the long pale fibers on the corn (Zea mays) cob. You can buy it at an herbalist, or harvest them off supermarket corn and dry them on some paper towels. Make tea with them (about an ounce of dry cornsilk to 1 quart of water just off the boil; cover and steep 15-20 minutes, strain and drink throughout the day.) Marshmallow (Althea officinalis) is another good soothing, demulcent herb often traditionally used for kidney stones, either alone or in conjunction with cornsilk. Marshmallow extracts best in a cold water infusion, but it’s pretty gross that way - it comes out like snot. I usually let the cornsilk infuse for about 10 minutes and then add the marshmallow to the now slightly cooler water and let it go another 10 minutes. You don’t get quite as much snotty mucilage that way, but you still get a good final product.

If that doesn’t do it, ask your doctor about using a urinary antispasmodic medication until it passes. Sometimes that can make it hurt a little less.

Hang in there! This too shall…well, you know…

6

It seems that it’s not what is recommanded any more. Not unanimously, though. At the hospital, they told me todrink a lot. Then, my doctor told me not to drink (more exactly : to drink no more than 3/4 of a liter/day). Confused by conflicting advices, I asked the pharmacist who told me not to drink. Some days later my doctor’s brother (also a doctor) told me again not to drink. After checking on the internet, I found out that it’s currently most often recommanded to limit water intake during crisis (and to drink more when you’re not passing a stone. But I usually drink a lot anyway).

The “flushing it out quickly” is the reason why drinking a lot was recommanded, indeed, but from articles I read, it seems it’s not terribly effective, that the resulting increase of pressure in the kidneys damage them, and the resulting pain make them enter in a vicious circle (hormone production, resulting in greater blood flow, resulting in greater kidney activity, resulting in a larger build-up of urine, resulting in more pain, etc…until the kidney “freeze” which is apparently a bad thing). Don’t take this summary as accurate, I’m probably misremembering a lot, but the general idea is that it’s nowadays often not advised to drink.

So, I guess that this issue is still debated, but given how bad the pain is, I’m going with the advice that will reduce said pain.

7

Interesting. Where did you find that on the 'net? Current clinical recommendations in the US (last updated July 2013, last literature review Sept. 2013) still strongly favor hydration, and doing so by IV if PO intake is inadequate. Though hyperhydration by IV is no longer recommended, as it’s been found to not be an improvement over basic hydration.

8

Yes, they prescribed it to me at the hospital, but without giving any explanation. So, when some days later I asked my doctor’s brother about why I had been prescribed this, since it’s apparently a prostate medication, he had no clue. He guessed that they might have seen something on the prostate when they did a sonography (they didn’t tell me anything about the sonography results, nor did they join any image or write any conclusion). I figured out what it was for by reading an urology article on the internet (while searching about the water intake issue)

I already have this too. Even though again advices are conflicted, some (like my pharmacist) thinking that it’s useless :rolleyes:

Add to this the fact that my doctors’ brother told me that the pain comes mainly from contraction of the ureter muscles around the stone, while I read later on the internet that this concept was unproven and mostly discredited, while the pain would come almost solely from the accumulation of fluid in the kidney (which seem to conflict with the idea of prescribing antispasmodics and alpha-blockers, but whatever).

And also the fact that despite two others major crisis after the first one (and of course an untold number of less serious but still painful ones), he refused to prescribe morphin mostly because “it will eventually go away in some days” while I verified later that quite a lot of other doctors do prescribe and/or inject it. At the hospital, they injected morphin upon my arrival, then a doctor precribed codeine, then another stroke it out, I strongly suspect precisely because I asked about pain treatment. My doctor reinstated codein. Both claimed (wrongfully, I doubt they didn’t know that, and even if they didn’t, they should have) that the generic painkiller + antinflammatory+ antispasmodic would deal with the pain.

Plus the complete lack of informations given at the hospital and other things, and I can tell you I’m pretty unhappy with doctors currently. Passing a stone isn’t that rare of an ailment (in fact, I read it amounted to a very signifant part of all the people received in emergency services in France, something like 5-10%), and I would have expected to receive knowledgeable, non conflicting, and not mistaken advices and prescriptions. Apparently, 4 doctors (two at the hospital, two brothers I visited), 2 pharmacists (in the same pharmacy) and one radiologist aren’t enough to get a complete picture without reading up on the internet to separate the chaff from the grain. I can’t believe this.

9

Except for the fact that it was in French, I’ve no clue. I googled colique nephretique douleur (passing stone, pain) and read up everything from self-medication forums to files provided to medical students to urology articles for a couple hours.

This advice was not unanimous, however. I remember a procedure file signed by a lot of urgentists and recommanding to let the patient drink freely while hospitalized and to tell him to drink normally once he has been sent back home, for instance.

FTR, it seems that drinking less does significantly reduce pain. I was mostly pain-free today and yesterday (drinking a litre and eating very little) after a couple days of mostly uninterrupted pain. On the other hand I can’t be sure. Tuesday and Wenesday had been relatively pain-free too despite me not paying much attention to what I was drinking.

10

Tom Scud just went through a couple of rounds of this over the past month, and pushing fluids, combined with Vicodin, seemed to do the trick. Don’t know whether they told you how large your stones are, or what kind…Tom is due for another appointment to get dietary/lifestyle advice to (hopefully) prevent them in the future, because this is not his first adventure. But all the advice either of us has ever seen in English, as well as the multiple internists he’s now seen and the board-certified urologist, advise pushing fluids.

The dietary advice for prevention is really confusing, though - if you can make any sense out of this, I’m all ears!

P.S. It is awfully nice to have the kind of relationship with a primary physician that if you page him and say “hey, I seem to be passing a kidney stone,” he is actually willing to call in a prescription for narcotics without seeing you in the office fist. Especially when it’s at night. It kept Tom out of the ER, anyway. It probably helped that the last round was ~ 4 years ago, and that he brought back a nice rock in a jar for analysis afterwards.

11

I know, it’s frustrating. But it’s also not very surprising - we don’t know nearly as much about the human body as most people assume. We’ve got lots of theories, but those theories are constantly revisited as new information becomes known. “Modern medicine” is, what, 150 years old? You’ve got taverns older than that. So we make the best recommendations we have on the best information we have at the moment - or the latest research your doctor has had time to read lately. Added to the frustration is that bodies don’t read the damn textbooks. Some of them do better with some treatments and others others, and often with apparently identical conditions.

Is this “high pressure” theory backed up with measurements, or only reason? I ask because we were taught (and this may be entirely outdated, obviously) that the pressure through the kidneys was kept fairly constant, by a complicated mish-mash of hormones and metabolites, until you got into truly clinically significant dehydration or low/high blood pressure.

<0.75L a day is *really *significant fluid restriction. What our doctors sometimes recommend for “Fluid Restriction” for congestive heart failure varies, but is usually 1L/day or 1.5L a day. So maybe they are intentionally pushing you, temporarily, into that “clinically significant dehydration” state. I’m sorry, I know nothing of this approach, so I’ll shut up now, except to wish you the best. :slight_smile:

12

I really don’t think pain is (solely) caused by hydronephrosis. I’ve seen a lot of patients in a lot of pain with non-obstructing kidney stones.

And most studies have shown tamsulosin to be more effective than placebo by a large margin at helping facilitate stone passage.

Other studies have shown that opioids like morphine, codeine, etc. are no more effective than NSAIDs like ibuprofen or keterolac, but I think that’s very dependent on the patient’s own pain physiology. If a patient gets inadequate relief from keterolac, I break out the oxycodone or morphine for them.

13

I had no clue that marshmallow originally came from a plant’s roots. I’ll visit the pharmacy tomorrow. I’ll gibe a try to hot water bottles too, recommanded on some boards.

14

Good luck. Bear in mind that this is traditional use that I personally have had luck with. I can make no guarantees, as they haven’t been scientific method tested that I know of. But neither do they have significant warnings (a theoretical but not clinically observed warning for potential hypoglycemia in diabetics and, for cornsilk, a possible exacerbation of already low blood potassium levels) and no potential drug interactions, unlike a couple of the other common kidney stone herbs. I believe them to be in the category of “couldn’t hurt, may help,” but I’m contractually obligated to remind you to check all herbs and supplements with your doctor. :wink:

15

It’s 4 mm. I had a scanner done since, lacking any sonography result, my doctor didn’t know if they had positively identified a stone or not. On the other hand the kind is unknown. After I enquired, my doctor’s brother told me analyzing the stone isn’t necessary for a single occurence in a lifetime and that besides it was very costly and not reimbursed by the healthcare system. In fact, he was wrong. I asked in the nearest laboratory and they told me it costs only € 30. I’ll make to sure to have the fucker analyzed for future reference.

Apparently not the case over here. I’m guessing from what I read that recommandations went from “drink a lot” to “drink as little as possible” to “drink normally” over the years. I suspect this might the reason why I got conflicting advices, although it might be also a matter or individual opinion (the doctor who told me to drink a lot at the hospital was rather young, for instance)

I had seen this doctor (and his twin brother when he’s not present) for 16 years. I thought we had this kind of relationship. But his reluctance, and his brother’s clear refusal to prescribe narcotics for an inambiguous case of something that is known to be very painful pissed me off quite a lot (even moreso since I’ve a big issue with the policy of severely restricting the prescription of narcotics to begin with. I think it’s basically immoral. So, obviously, I’m even more upset when I’m the one in pain) made me wonder if I shouldn’t seek another primary physician. I used to be really happy with mine, but now I can only guess that I’ll be denied proper pain treatment if I need it (and it might be for a condition much more dubious than passing a stone). Also, his brother’s inability to determine why I was prescribed Tamulosine even though it seems to be a standard treatment for a common ailment made me pause.
Regarding dietary advice : I understand it depends a lot on the type of stone. Besides, as my physician said, passing a stone every 48 years might not require dietary restrictions. I’ll look into this when I’ll have passed the stone and had it analyzed.

Anecdote : 15 years ago or so, it was determined that my mother had a very big stone in one of her kidneys. First medical advice : remove the kidney. Second medical advice : drink 3-4 liters/ day of water X for three months and let’s see. The second advice worked. This time too, I couldn’t believe that she was told to get surgery while drinking a lot of mineral water proved to be sufficient.

16

A recent Cochrane Review (a very high quality set of reviews) declares that vigorous hydration, used with diuretics, isn’t of proven benefit.

However, the standard of care for the management of acute renal colic according to UpToDate (in my opinion the single best source for contemporary evidence-based therapeutics) includes “hydration”*.

*I admit this is essentially an ‘appeal to authority’ argument but, regardless, it does constitute a de facto standard of care.

17

I would note that this is for people hospitalized and shiort term results, apparently (whether or not they passed the stone after 6 hours, it seems). It might not apply very well to people in my situation. For instance, if I had received hydration and duretics and the stone had passed after, say, 6 days, it wouldn’t have been considerd a success for the study’s purpose (and probably not by me, either) even though it would have been better than what actually happened. Or at the contrary, since the stone is still there after a dozen days, I guess it’s more likely that it’s actually blocked and that it’s not going anywhere, hydration or not.