Nephrolithiasis (Kidney Stones -- Very treatable)

Let's be clear: I am not a medical doctor and I am not licensed to provide medical treatment. However, I can give informal / general health suggestions that you may wish talk over with your physician (nephrologist) who is licensed to help you.

This is just a quick post concerning the fun fun fun topic of Kidney Stones. I have had some mild ones, but many people that have had some that hurt as much as childbirth. For mine, I just drank some Crystal Light which has potassium citrate (and water, of course) and it cleared up after a few days of that ... obviously the potassium citrate in Crystal Light might not have done anything for me (and the stones just went away on their own, more or less) or what works for me may not work for anyone else, and so don't do something just because it worked for me. However, the point of me writing this is to encourage those who do have a problem with these kidney stones is that I'm encouraging you to prevent and treat them non-invasively, if possible. According to a nephrologist I spoke with (check this out yourself ... don't just take my word for it), essentially 100% of them can be prevented. I had a roomate in my undergraduate years who had a kidney stone disease (Cystinuria) that quite possibly has killed him by now. The thought that something preventable (by taking a few pills and drinking a bunch of water ... really not hard) kills people disturbs me. As long as the problem goes away and never comes back (and doesn't cost you a fortune and tons of pain to treat), you will be happy.

Those devils can get caught and sometimes even need to be removed by a urologists. In fact, many urologists remove kidney stones all the time ... it's a lot of work for these physicians. If thes stones are preventable, why are so many people suffering from them? I'm not really sure. However, if you or anyone you know suffers from kidney stones, you really should see a nephrologist who is skilled in treating and preventing kidney stones.  If you have one, your chances of getting another one are quite good. Why anyone would want to have an expensive invasive procedure instead of getting an oral ("pill") treatment is beyond me. Anyway, if this is an issue for you or someone you care about, here is a little information you can take to your doctor and ask them more about it. Doctors often *hate it* when patients bring them information from the "Internet." However, it's your health, so be persistent.

Although I have access to official medical sources, I cannot quote them here for obvious copyright restrictions. Thus, I'm going to cite some information from wikipedia which is not a realiable medical source, but it's free ... so unless you have a subscription to a medical information provider or medical journals (both of which are copyrighted), you would have a hard time finding more accurate information among all the treatments that don't work.

Here is the information you may want to ask your physician about:

http://en.wikipedia.org/wiki/Kidney_stone#Treatment
[edit] Prevention
Preventive strategies include dietary modifications and sometimes also taking drugs with the goal of reducing excretory load on the kidneys:[31][21]
Drinking enough water to make 2 to 2.5 liters of urine per day.
A diet low in protein, nitrogen and sodium intake.
Restriction of oxalate-rich foods, such as chocolate, nuts, soybeans,[32] rhubarb and spinach, plus maintenance of an adequate intake of dietary calcium. There is equivocal evidence that calcium supplements increase the risk of stone formation, though calcium citrate appears to carry the lowest, if any, risk.
Taking drugs such as thiazides, potassium citrate, magnesium citrate and allopurinol, depending on the cause of stone formation.
Some fruit juices, such as orange, blackcurrant, and cranberry, may be useful for lowering the risk factors for specific types of stones.[33][34]
Avoidance of cola beverages.[35][36]
Avoiding large doses of vitamin C.[37]
For those patients interested in optimizing their kidney stone prevention options, it's essential to have a 24 hour urine test performed. This should be done with the patient on his or her regular diet and activities. The results can then be analyzed for abnormalities and appropriate treatment given.
[edit] Diuretics
Although it has been claimed that the diuretic effects of alcohol can result in dehydration, which is important for kidney stone sufferers to avoid, there are no conclusive data demonstrating any cause and effect regarding kidney stones. However, some have theorized that frequent and binge drinkers create situations that set up dehydration: alcohol consumption, hangovers, and poor sleep and stress habits. In this view, it is not the alcohol that creates a kidney stone but it is the alcohol drinker's associated behavior that sets it up.[39]
One of the recognized medical therapies for prevention of stones is thiazides, a class of drugs usually thought of as diuretics. These drugs prevent stones through an effect independent of their diuretic properties: they reduce urinary calcium excretion. Nonetheless, their diuretic property does not preclude their efficacy as stone preventive. Sodium restriction is necessary for clinical effect of thiazides, as sodium excess promotes calcium excretion. Though some have said that the effect probably fades after two years or so of therapy (tachyphylaxis), in fact it is only randomized controlled trials lasting 2 years or more that show the effect; there is really no good evidence from studies of calcium metabolism that the thiazide effect does not last indefinitely. Thiazides are the medical therapy of choice for most cases of hypercalciuria (excessive urinary calcium) but may not be suitable for all calcium stone formers; just those with high urinary calcium levels.

[edit] Allopurinol
Allopurinol (Zyloprim) is another drug with proven benefits in some calcium kidney stone formers. Allopurinol interferes with the liver's production of uric acid. Hyperuricosuria, too much uric acid in the urine, is a risk factor for calcium stones. Allopurinol reduces calcium stone formation in such patients. The drug is also used in patients with gout or hyperuricemia, but the latter is not the critical feature of uric acid stones.[40] Uric acid stones are more often caused by low urine pH. Even relatively high uric acid excretion will not be associated with uric acid stone formation if the urine pH is alkaline. Therefore prevention of uric acid stones relies on alkalinization of the urine with citrate.
Allopurinol is reserved for patients in whom alkalinization is difficult. For patients with increased uric acid levels and calcium stones, allopurinol is one of the few treatments that has been shown in double-blinded placebo controlled studies to actually reduce kidney stone recurrences. Dosage is adjusted to maintain a reduced urinary excretion of uric acid. Serum uric acid level at or below 6 mg/dL is often the goal of the drug's use in patients with gout or hyperuricemia.

[edit] Decreased protein diet
A high protein diet might be partially to blame. Protein from meat and other animal products is broken down into acids, including uric acid. The most available alkaline base to balance the acid from protein is calcium phosphate (hydroxyapatite) from the bones (buffering). The kidney filters the liberated calcium which may then form insoluble crystals (i.e., stones) in urine with available oxalate (partly from metabolic processes, partly from diet) or phosphate ions, depending on conditions. High protein intake is therefore associated with decreased bone density as well as stones. The acid load is associated with decreased urinary citrate excretion; citrate competes with oxalate for calcium and can thereby prevent stones.
In addition to increased fluid intake, one of the simplest fixes is to moderate animal protein consumption. However, despite epidemiologic data showing that greater protein intake is associated with more stones, randomized controlled trials of protein restriction have not shown reduced stone prevalence. In this regard, it is not just dietary calcium per se that may cause stone formation, but rather the leaching of bone calcium. Some diseases (e.g., distal renal tubular acidosis) which cause a chronically acidic state also decrease urinary citrate levels; since citrates are normally present as potent inhibitors of stone formation, these patients are prone to frequent stone formation.

[edit] Other modifications
Potassium citrate is also used in kidney stone prevention. This is available as both a tablet and liquid preparation. The medication increases urinary pH (makes it more alkaline), as well as increases the urinary citrate level, which helps reduce calcium oxalate crystal aggregation. Optimal 24 hour urine levels of citrate are thought to be over 320 mg/liter of urine or over 600 mg per day. There are urinary dipsticks available that allow patients to monitor and measure urinary pH so patients can optimize their urinary citrate level.
Though caffeine does acutely increase urinary calcium excretion, several independent epidemiologic studies have shown that coffee intake overall is protective against the formation of stones.[41]
Measurements of food oxalate content have been difficult and issues remain about the proportion of oxalate that is bio-available, versus a proportion that is not absorbed by the intestine. Oxalate-rich foods are usually restricted to some degree, particularly in patients with high urinary oxalate levels, but no randomized controlled trial of oxalate restriction has been performed to test that hypothesis.

[edit] Calgranulin
Crystallization of calcium oxalate (CaOx) appears to be reduced by molecules in the urine that retard the formation, growth, aggregation, and renal cell adherence of calcium oxalate. By purifying urine using salt precipitation, preparative isoelectric focusing, and sizing chromatography, some researchers have found that the molecule calgranulin is able to inhibit calcium oxalate crystal growth.[42] Calgranulin is a protein formed in the kidney. Given the large amounts of calcium oxalate in the urine, and considering its potency, calgranulin could become an important contribution to the normal urinary inhibition of crystal growth and aggregation. If so, it will be an important tool in the renal defense against kidney stones.

http://en.wikipedia.org/wiki/Cystinuria
Cystinuria
Cystinuria is an inherited autosomal recessive disorder and is characterized by the formation of cystine stones in the kidneys, ureter, and bladder.

[edit] Causes
Cystinuria is characterized by the inadequate reabsorption of cystine during the filtering process in the kidneys, thus resulting in an excessive concentration of this amino acid. Cystine may precipitate out of the urine, if the urine is neutral or acidic, and form crystals or stones in the kidneys, ureters, or bladder.
Mutations in the SLC3A1 and SLC7A9 genes cause cystinuria. The SLC3A1 and SLC7A9 genes provide instructions for producing the two parts of a transporter protein that is made primarily in the kidneys. These defects prevent proper reabsorption of basic, or positively charged amino acids such as histidine, lysine, ornithine, arginine and cystine.[1] Normally this protein allows certain amino acids, including cystine, to be reabsorbed into the blood from the filtered fluid that will become urine. Mutations in either of these genes disrupt the ability of this transporter protein to reabsorb these amino acids, allowing them to become concentrated in the urine. As the levels of cystine in the urine increase, the crystals typical of cystinuria are able to form, resulting in kidney stones. Cystine crystals form hexagonal-shaped crystals which can be viewed upon microscopic analysis of the urine. The other amino acids that are not reabsorbed do not create crystals in urine. The disorder affects 1 in 7,000 people, making it one of the most common inherited diseases, and the most common genetic error of amino acid transport. Cystinuria is inherited in an autosomal recessive pattern.

How can it be treated (this is something we learned in class ... again ask your doctor). Here are aspects of treatment your physician may consider:
* High fluid intake > 3L per day
* Potassium citrate
* D-penicillamine
* beta-mercaatoproprionyl-glycine

But, please don't just have the stones removed by invasive procedures. Work with your physician to try to prevent them.

Again, let's be clear: I am not a medical doctor and I am not licensed to provide medical treatment. However, I can give informal / general health suggestions that you may wish to talk over with your physician (nephrologist) who is licensed to help you.

Handheld computers for medicine

Someone asked me a few questions about my Palm computer, so I thought I would share the answers here in case anyone else is interested:

Question: (A medical student asks) I am interested in using a Palm TX handheld computer (to use on my rotations). Did it ever crash on you? did it ever work strangely? ? The Palm techs say that third-party software is sometimes incompatible and is a major source of tx breaks, so careful of what you download! Do you have any other medical software on your tx that havent caused resets?

Answer: I use the Palm TX for Epocrates only. It works well for that. I have a Blackberry Curve for messaging and Tablet PC (Lenovo X61) for taking notes in clinics.

The Palm has occasionally “crashed” (frozen up and needs to be reset). However, for the most part, it has worked very well, especially with Epocrates, which is a very stable application. Some of the other applications (such as the PowerPoint emulator) can get overwhelmed with large documents.

I have used this particular Palm TX for about 9 months. In the past I used Palm computers all the time. Right now I prefer tablet computers and only use the Palm if I don’t have internet (e.g., many hospitals and clinics) and need to figure out a DDx or look up a drug. I may activate cellular internet service for my tablet so that I can access internet, but even cellular service does not work in many hospitals. I would like to get away from the Palm TX because I really want all my stuff on one machine (like my tablet) and the Palm TX is really not powerful enough for me. However, my Palm TX is very nice for DDx and looking up drug when I’m being pimped, need a DDx, or need drug information. Epocrates has a ton of information and you can also take word documents, small powerpoint files (don’t even try to put a 50 MB powerpoint file on this). Also, most doctors don’t have an engineering background like me and would really rather not carry around a tablet computer (they like the more compact Palm or a phone better). I also have the free Epocrates on my Blackberry.

Yes, there are some applications that are not compatible, but many of them are. The bigger issue in my mind is that Palm is phasing out the handheld Palm like in favor of their Palm Treo and Palm Smartphone line. Really the Palm TX is not a bad machine. It’s a little slow and it’s not going to work with our VPN or super-secure wireless network. It does go wireless on most public and home gateways (mine anyway).

I have several medical applications on it (IV dosing and the like). Epocrates also comes with a ton of BMI, CME, and other software. Again, I prefer to use my tablet computer but unfortunately Epocrates is not available for it. There are many more applications available for the PC than for the Palm. However there are many Palm medical applications. So far I haven’t really run across something that is anywhere close to Epocrates.