K IDNEY D ISEASE : K IDNEY S TONES Mitchell Thom Ms. Bragg 05/03/11 SBI4U

W HAT IS I T ?(B ACKGROUND I NFO ) In science class, we learn about different types of chemical reactions; one being a reaction involving a precipitate. Kidney stones, known for causing excruciating amounts of pain, are hard, crystalline stones made because of precipitates formed in the kidneys. The precipitates are due to certain combinations of solutes in the nephron depending on the type of stone. These stones eventually pass through the ureter, blocking urine and causing the ureters to swell, which is the source of the great pain that patients experience. Another name for this condition is nephrolithiasis.

W HAT IS IT ? (T YPES OF S TONES ) There are different types of kidney stones, the most common being calcium oxalate and calcium phosphate stones, while there are also cysteine stones, uric acid stones, and other uncommon types like struvite stones. The stones are organized into two types: alkaline and acidic. The calcium phosphate and oxalate stones are categorized into the alkaline category, while the cysteine, uric acid, and struvite stones are named acidic.

T YPES OF S TONES CNTD. Cysteine and struvite stones are different from the other types of stones. Cysteine stones are developed due due to excess cysteine in the urine because of a genetic disorder called cystinuria. In this condition, trouble with the transport of amino acids leads to a higher concentration of amino acids in the urine. Since cysteine is the least soluble of all amino acids, it tends to precipitate in urine in the form of stones. An infection in the urinary tract can lead to kidney stones, and these are known as struvite stones.

H OW DOES IT AFFECT THE KIDNEY ? Kidney stones do not affect any specific area of the nephron. Rather, the kidney stones are formed in small fragments wherever there is a decrease in urine volume and/or an excess of precipitate-forming solutes in the urine. This means that miniscule kidney stones can form anywhere between the bowman’s capsule and the collecting duct, and the collecting ducts will gather in the renal pelvis where all of the fragments can form a larger kidney stone. From here, the kidney stone will enter the ureter, which is only 0.4 mm in diameter.

L ET ’ S GET SCIENTIFIC Strenuous exercise without fluid intake, low volumes of urine, and a high concentration of precipitate-causing solutes are all conditions where kidney stones can form, but why? Strenuous exercise means more water reabsorption, since there is will be a higher concentration of NaCl in the blood due to less water. This means water will diffuse into the blood because it will follow NaCl. This leaves a lower volume of urine, and therefore a higher concentration of solutes.

S CIENCE OF K IDNEY S TONES With these factors in mind, picture fluids moving through the nephron. If there is a low volume, the urine will sit in the nephron for longer, and this allows precipitate- forming solutes to mix, which will result in a greater chance of kidney stone fragments forming. If there is more water, there is higher pressure in the nephron. This means the fluids will move more quickly and have a lower chance of settling.

S YMPTOMS OF K IDNEY S TONES Include: Excruciating onsets of pain in your sides or lower back Blood in Urine Difficulty Urinating Fever and Chills (If associated with infection in urinary tract) The ureter is only 0.4 mm in diameter, so even very small kidney stones can cause large amounts of pain. Because of the crystalline shape of the kidney stone, its uneven, jagged edges can cut into the sides of the renal pelvis and the ureter, causing pain and blood in the urine. If the stone is large enough, it can block the transport of urine to the bladder, causing the difficulty to urinate.

D IAGNOSIS OF K IDNEY S TONES Diagnosis is suspected by the symptoms of kidney stones, but confirmed by a helical CT scan of the abdomen. A helical CT scan is a specialized form of CAT scan that allows patients to be continuously be scanned with movement. It also permits a higher definition of internal structures, like the kidneys and ureter. This is the procedure used because patients are usually in so much pain they are treated as emergency cases and need to be diagnosed quickly even if they are writhing in pain. The helical CT scan can provide 3D images.

D IAGNOSIS CTND. In the cases of blood sampling and urinalysis, neither would be efficient at determining the presence of kidney stones because: The patient may not be able to urinate The patient will most likely not cooperate due to pain The patient will need to be diagnosed in as little time as possible, and these procedures will take a very long time to centrifuge the urine, etc.

A RE KIDNEY STONES INHERITED ? No. Kidney stones can develop in anybody. However, there are certain diseases, like cystinuria, which was mentioned before, that can cause excess cysteine to be in a person’s urine. This doesn’t mean that cysteine kidney stones can be inherited, but there are genetic disorders involving concentrations of solutes in urine that can increase your chances of having kidney stones. Eg. Gout (increased concentration of urea in blood and urine), Hypercalciuria (high calcium in urine, half of patients get kidney stones in their lives), and hyperoxaluria (high chances of calcium oxalate stones). All of these diseases are genetic disorders.

K IDNEY STONES INHERITED ? C TND. For those who do not have any of these disorders, kidney stones are still possible. Any of these reasons could cause kidney stones: Dehydration, more reabsorption. Eating high-oxalate foods leaves more precipitate- forming oxalate solute in urine. Taking in excess calcium leaves more precipitate- forming calcium solute in urine. Eating very protein-heavy diets can lead to excess uric acid in the diet due to digestion, which can lead to uric acid stones.

H ISTORY OF T REATMENT Kidney stones have existed since the beginning of civilization. In 1901, an Egyptian mummy dating back to 4800 BC was found with a kidney stone in its pelvis. Individuals like Sir Isaac Newton and Benjamin Franklin also had kidney stones. Practices of Lithotomy, or surgical removal of kidney stones, have been used for centuries. (It is one of the oldest surgical procedures created.) In 1878, Henry Jacob Bigelow invented the practice of litholapaxy, which dropped mortality rates from 24% to 2.4%. li·thol·a·pax·y : The procedure of crushing of a stone in the bladder and washing out the fragments through a catheter.

T REATMENT CNTD. It wasn’t until 1980 that the current treatment for kidney stones was created. Dormier MedTech, an aircraft manufacturer, introduced extracorporeal shock wave lithotripsy at this point in time, a procedure that breaks up stones through acoustic pulses. ESWL: a non-invasive procedure where an x-ray locates the kidney stone, and a sedated patient has a high-intensity acoustic pulse aimed at the area with increasing intensities to get the patient used to the sensation. The final power level depends on the patients threshold, by this point the stone should break. If it hasn’t yet, the patient is sedated more heavily to allow a higher power level.

ESWL ESWL isn’t without risks, unfortunately. The shockwaves can lead to capillary damage, hemorrhage, renal failure, and hypertension. Fragments of a Kidney Stone after ESWL treatment

W ERE YOU PAYING ATTENTION ? 1. Which types of kidney stones are acidic and alkaline? 2. Why can strenuous exercise without fluid intake increase the chances of a kidney stone forming? 3. How can you decrease your chances of getting a kidney stone?

A NSWERS

B IBLIOGRAPHY Photos: X-Ray: Myqute. "How to Say Goodbye to Kidney Stones." Promote Your Blog, Get Discovered and Expand Your Audience with BloggersBase.com. Sept Web. 03 May cm Kidney Stone: Barton, Joe. "What about What Do Kidney Stones Look like on Ultrasound." Kidney Stone Treatment - Pain Relief With This Safe And Effective Home Kidney Stone Remedy! Web. 03 May "Renal System." The Birmingham City University Health Website. Web. 03 May "CT Scan." Shikoku.ne. Web. May 3..

B IBLIOGRAPHY CNTD. Websites: (Amazing Source) Shier Jr., William. "Kidney Stones Symptoms, Treatment Options, Diet, Causes, Signs and Prevention by MedicineNet.com." Medicine Net. Web. 03 May "Department of Urology, University of Kansas Medical Center." Kidney Stones Web. 04 May