Kidney Stone Treatment: Diet, Pain Management & Removal

For many people with a kidney stone treatment is often unnecessary. Most calculi are spontaneously passed in the urine. Ninety percent of small stones (less than 1/4 inch, or four millimeters) pass without any need for treatment at all. Stones that measure five to seven millimeters can be passed about half of the time. Once a stone exceeds seven millimeters in diameter, however, some form of intervention is usually required. This can involve medications, surgical removal of the kidney stone, or lithotripsy to break up the stone so it can be passed.

Pain Management

Over the counter medication is rarely adequate for pain management. Prescription oral analgesics provide relief for mild to moderate kidney stone pain. The oral analgesics prescribed most often for pain management include diclofenac, acetaminophen with codeine, and propoxyphene HCL.

For severe pain, injections of narcotics such as morphine and Demerol may be required. The use of narcotic painkillers is reserved for severe cases due to the risk of dependency or accidental overdose.

Analyzing Kidney Stones

Even if the stones are passed naturally, the stones should be collected for analysis. Determining their chemical composition can help a physician determine what measures you need to take to prevent further stone formation.

Stones are collected by straining the urine. This is accomplished by urinating through a fine mesh — your doctor or clinic can provide the equipment you need. It may be several days before the stone is passed.

Non-Surgical Kidney Stone Treatment

Stone composition analysis, urine chemistry, and blood tests determine the causes of stone formation and the treatment required to control the condition, hopefully preventing future stone development. Preventive treatment for kidney stones often involves changes to diet, taking specific mineral and vitamin supplements, and increasing fluid intake.

Cystinuria (high levels of cystine in the urine): Your physician is likely to recommend increased fluid intake. Measures may be taken to increase your urine pH, often with bicarbonate, or your condition may be treated with penicillamine and tiopronine.

Hypercalciuria (high levels of urinary calcium): Your doctor may recommend thiazide diuretics to reduce urinary calcium levels. Avoid restricting calcium in your diet, as doing so often causes the formation of calcium-based stones.

Hyperoxaluria (high levels of oxalate salt in the urine): This condition may be prevented with dietary changes. Reduce your intake of cocoa, tea, spinach, nuts, and pepper. Your physician might also recommend daily pyridoxine (vitamin B6) supplements and increased fluid intake. Occasionally, phosphate therapy or calcium citrate supplements are required.

Hyperoxaluria, Enteric (high levels of urinary oxalic acid due to an intestinal disorder): Your doctor may recommend a low fat diet, increased fluid intake, and the use of calcium citrate, magnesium, and cholestyramine supplementation to reduce oxalate levels.

Hyperuricosuria (high levels of uric acid in the urine): You should restrict purines (nucleic acids) in your diet, and drink at least three liters of water daily. Foods high in purines include meat, fish, and poultry. Your doctor may prescribe allopurinol, which limits the accumulation of uric acid.

Hypocitraturia (low levels of urinary citrate): Supplements such as potassium citrate may be prescribed to raise citrate levels, and citrus fruits and lemons may be added to your diet.

Surgical Kidney Stone Removal
In the past, when surgery was the only option for the relief of kidney stones, treatment involved an incision in the back, and then the removal of the kidney stones by cutting through the kidney or ureter. Recovery times took weeks, and a lengthy hospital stay was required. Open surgery is rarely used today. With technical advancements for kidney stone removal, treatment has become much less invasive.

Ureteroscopy: A ureteroscopy is performed on an outpatient basis, either with general or local anesthetic. A flexible, hollow tube called a ureteroscope is inserted through the urethra and bladder, and then into the ureter. Ureteroscopy is used to remove or fragment calculi in the lower portion of the ureter.

If the stone is small enough, a "basket extraction" may be performed. Using diagnostic images from ultrasound or other tools, the surgeon catches the calculus in a small basket threaded through the ureteroscope. If the stone proves too big for removal in this manner, it is broken up using a laser beam, and the small pieces are passed in the urine.

Percutaneous Nephrostolithotomy (PCN): A percutaneous nephrostolithotomy, or PCN, involves a small incision in the skin. Under anesthetic, a needle with a wire guide is inserted through the incision and directed to the calculus. Hollow catheter tubes are threaded down the wire. Surgical tools are then threaded through the catheters, and the calculi are broken into small pieces to aid in the removal of the stone.

A PCN is appropriate for medium to large calculi. It requires a brief hospital stay and a two-week recovery period.

Lithotripsy Techniques: Ultrasound & Sound Waves

Lithotripsy techniques are used to break down stones in the kidneys and the upper part of the ureter. The stones are broken down so the smaller pieces can be passed with urine. None of the following techniques are recommended for larger stones.

Ultrasonic Lithotripsy: An ultrasound probe is inserted through the urethra and bladder, then into the ureter. The ultrasound probe uses sound waves to break up the obstruction. Stone fragments are then either removed or allowed to pass out of the body during urination.

Electrohydraulic Lithotripsy (EHL): Instead of sound waves, shock waves generated by electrical impulses break up the stone. A probe is positioned close to the mass, and the waves pulverize or break it up. An EHL is performed under general anesthetic, and can break up a stone located anywhere in the urinary tract.

Extracorporeal Shock Wave Lithotripsy (ESWL): Like electrohydraulic lithotripsy, shock waves are directed at the stone to break it apart. However, ESWL directs the shock waves through the skin. ESWL should not be used to break up struvite stones, nor should it be used to treat large stones measuring over one inch in diameter. Pregnant women should not undergo ESWL.

Resources

Beers, M. H., & Berkow, R. (ed). Urinary calculi. The Merck Manual of Diagnosis and Therapy, 17th Edition. Merck Research Laboratories, NJ, 1999.

Browne, G. & Plant, L. (updated 2004). Kidney stones. Renal Unit of the Royal Infirmary of Edinburgh.

Fauci, A., Braunwald, E., Isselbacher, K., Wilson, J., Martin, J., Kasper, D., Hauser, S., & Longo, D. (ed.). Harrison's Principles of Internal Medicine, 14th Edition. McGraw-Hill, NY, 1998.

Carson-Dewitt, R.S. (1999). Kidney stones. Gale Encyclopedia of Medicine.

Kidney Stone Treatment and Prevention Centers. (nd). About kidney stones. LithoLink.com.