Overview: Kidney Stones

• Over the past few decades, an increasing percentage of the U.S. population has had the misfortune of experiencing the disabling pain that accompanies urolithiasis.

• The National Health and Nutrition Examination Survey (NHANES) reported that approximately 5% of persons in the United States will have experienced at least one symptomatic stone in their lifetime. Notable epidemiologic risks include being white, male, and living in hot, arid regions.

• As evidenced by Hippocrates' reference to "...persons laboring under the stone...." in his famous oath, this common medical problem has challenged even history's most renowned healers.

• Data demonstrate certain epidemiologic disparities in gender, location, and race. For reasons that are still unclear, men consistently have a higher risk of developing kidney stones than do women. Geographically, the "stone belt," consisting of the southeastern U.S. region, also tends to have higher prevalence of renal lithiasis, likely because of its hotter climate.

• Finally, black U.S. residents appear to suffer less from this disease than do their white counterparts.

  To provide the most appropriate counseling, the clinician must understand how kidney stones form and what elements are commonly present in stones.

• Kidney stones are a product of normally soluble material (e.g.. calcium, oxalate) supersaturating in urine to a level that facilitates crystallization of that very material. With this origin in mind, any approach that discourages urinary crystallization or promotes crystallization inhibition forms the basis for the preventive recommendations described in this chapter.

• More than 80% of kidney stones primarily consist of calcium, usually calcium oxalate. These oxalate stones may also contain phosphate or uric acid.

• The remainder of kidney stones can be divided into stones that have uric acid, struvite (magnesium ammonium phosphate or infection stone), or cystine as their primary constituents. Most calcium stone formers possess some sort of urinary metabolic abnormality that can be detected with a 24-hour urine sample.

Important points to consider

• Patients with recurring stones or with a stone manifesting before they are 30 years old should have a 24-hour urine test to check for high levels of calcium, oxalate, and uric acid or low levels of citrate.

• Phyllanthus niruri may potentiate insulin and other antidiabetic medications, as well as antihypertensive medications. Do not take during pregnancy.

• Some anecdotal evidence indicates that acupuncture using techniques that facilitate energy manipulation of the kidney and bladder can help with acute stone-related pain and with stone recurrence.

• Medical expulsive therapy herapy is recommended for stones up to 10mm. Alpha blockers appear to o perform better with stones 5 to 10mm.

Prevention Prescription

• Maintain a daily fluid intake of 2 to 3 L (approximately 8 to 10 glasses of water). Try to limit situations that exacerbate dehydration (e.g., hot weather, endurance exercise).

• Do not limit your dietary calcium intake. A low-sodium, low-protein diet can be helpful. Drink lemonade, orange juice, and cranberry juice, but limit grapefruit juice and sodas.

• Develop a healthy lifestyle that maintains a normal body mass index.

• For patients with hyperoxaluria, limit intake of foods with high oxalate levels, including nuts (almonds, peanuts, pecans, walnuts, cashews), vegetables (rhubarb, spinach), and chocolate.

Integrative therapeutics review

The purpose behind these suggested therapeutic options for kidney stones is to prevent recurrence of symptomatic stones. Regardless of stone composition, all patients with kidney stones should be advised to increase their water intake. Depending on the type of stone and results of metabolic evaluation, additional dietary, supplemental, and medical recommendations can also be made. Surgery is reserved for patients with large stones, recalcitrant disease, obstructing disease, and stones located in certain positions along the urologic tract that are difficult to access.

Removal of Exacerbating Factors

• Avoid excessive exposure to any environment or activity that promotes dehydration (warmer climates or strenuous physical activity).

• Maintain general healthy eating and physical activity habits that prevent development of metabolic syndrome conditions (e.g., obesity, hypertension, hyperlipidemia).

Nutrition

• Drink lots of water, with 2 to 3 L per day recommended (8 to 10 glasses of water).

• Do not limit dietary calcium intake.

• Limit caffeine, soda, grapefruit juice, protein, carbohydrate, and salt intake (less than 2.5g daily). Drink lemonade, orange juice, and cranberry juice.

• Decrease consumption of oxalate-containing foods, especially if you have hyperoxaluria.

• Decrease intake of purine-rich foods, especially if you have uric acid stones.

• Tailor your diet based on the type of metabolic abnormality.

Supplements

• Limit supplemental calcium, but if needed for bone fortification, take with food.

• Limit supplemental vitamin C.

• Take supplemental omega-3 fatty acids.

• Take supplemental magnesium.

• Probiotics containing Oxalobacter formigenes can be used, especially if you have hyperoxaluria.

Botanicals

• Phyllanthus niruri (stonebreaker, chanca piedra): take 250 mg daily to twice a day before meals.

• Other Chinese herbs can be tried (Chorei-to, Wullingsan, Jin Qian Cao, and Niao Shi).

• Other herbs frequently used in Ayurvedic medicine (Tribulus terrestris, Orthospihon stamineus/grandiflorus [Java tea), and Dolichos biflorus) can be considered.

Energy Medicine

• Acupuncture can be used for pain after extracorporeal shock wave lithotripsy (ESWL) and possibly as a kidney or bladder energy-modifying treatment.

• Pharmaceuticals Diuretics, especially thiazides (hydrochlorothiazide, 25 mg daily) can be used for their hypocalciuric effect.

• Potassium citrate is useful as an alkalinizer and citrate promoter, at 10 mEq three times a day (if U greater than 150 mg/day) or 20 mEq three times a day (if U less than 150 mg/day) with meals, up to 100 mEq/day.

• Alpha, blockers (tamsulosin, 0.4 mg 30 minutes after a meal daily; maximum, 0.8 mg daily) and calcium channel blockers (nifedipine, 30 mg daily extended release) can facilitate stone expulsion.

• Allopurinol, at 200 to 300 mg daily, can help prevent uric acid stones.

Surgical Therapy

• ESWL is very successful for smaller stones (less than 1 cm) located in the distal ureter.

• Ureteroscopy can be used for larger stones that are located more proximally or are impacted.

• Percutaneous nephrolithotomy is reserved for recalcitrant stones and for staghorn calculi.

Key Web Sources

• http://kidney.niddk.nih.gov/kudiseases/topics/stones.asp

• http://www. nlm.nih.gov/medlineplus/tutorials/kidneystones/htm/index.htm

• http://www.webmd.com/