Healthcare South Home Page About Healthcare South Visit our pratices Useful forms Locate the information you are looking for Great links! Contact us with your comments or concerns How to benefit from our web site Patient information for new and current patients Parent resource and information center Health information for you and your family

ASK THE DOCTOR: ‘Wait and watch’ with kidney stones
By Dr. JIM MITTERANDO
The Patriot Ledger

Q. I was diagnosed, again, with a kidney stone last week. I was sent home from the emergency room and told it will pass in the next several weeks. I am in pain, frustrated and worried. What can I do?

A. A kidney stone is a common problem that affects 10 percent of men and 5 percent of women.

Kidney stones develop when chemicals dissolved in urine precipitate to form crystals. Inadequate fluid consumption can worsen this problem by concentrating the urine. Over time these crystals may combine to form a small, hard stone. This stone can break off and pass into the ureter - the tube that drains the urine from the kidney to the bladder - causing blockage and pain. Some people say the pain of a kidney stone is as severe as childbirth.

Prevention
If you have had a past kidney stone, you have a 50 percent chance of having another one in the future. You should drink 2 to 3 quarts of liquids per day to prevent the urine from becoming concentrated. Water is best. Too much soda may acidify the urine and make problems worse. At least 8 to 12 ounces of fluid should be ingested at bedtime, because urinary concentration usually occurs during sleep.

A diet that limits salt and meat intake has been shown to prevent kidney stones.

If you have recurrent stones, you should have a 24-hour urine study to determine if you overexcrete or underexcrete certain chemicals in the urine that may cause stones. This information can help your doctor to make specific recommendations to help prevent future stones.

Most stones are a combination of calcium and oxalate. Reducing foods high in oxalate may help some people to prevent future stones. Foods high in oxalate include nuts, spinach, okra, beets, rhubarb, strawberries, cranberries, soy, wheat bran, brown rice, chocolate, coffee and tea.

In the past, doctors restricted calcium intake for people with stones but now we know this may increase the risk of stones as well as increase the risk of osteoporosis. Dietary calcium helps to bind up oxalate in the colon and actually prevents stones. Women who have had kidney stones and who need to take a calcium supplement should take it with a meal and use the calcium citrate preparation. Citrate helps prevent stones.

Other preventative measures

  • Decrease sodium intake to less than 2,000 mg per day.
  • Limit animal protein to 8 ounces daily. Especially avoid liver and kidney meats.
  • Consider avoiding vitamin C supplements, which may increase oxalate.
  • Vitamin B6 may help prevent kidney stones by slowing oxalate production; but there are no good long-term studies that have tested this.
  • Sometimes a water pill called a thiazide (i.e. hydrochlorothiazide) is used to prevent excess calcium from being excreted.

Treatment
Most stones that are 4 millimeters or less will pass on their own without any intervention. Treatment mostly is a ‘‘wait and watch’’ approach, consisting of pain medications and aggressive hydration (at least 2 or 3 quarts of liquid per day). It can take several weeks for a stone to pass, which can be quite frustrating. During this time, it is important to strain the urine to catch the stone. Analyzing the composition of the stone may help guide later, preventative treatments.

If the stone does not pass after two weeks, follow up with an urologist is recommended. If you develop signs of an infection (fevers or chills), you will need emergency treatment.

If a stone is too large to pass, the urologist will remove it with a scope or break it up with ultrasound shock waves. If the stone is downstream near the bladder, the doctor can insert a scope into the bladder and through the ureter to retrieve it. If it is further upstream near the kidney, lithotripsy with shock waves may be used to break the stones into smaller fragments that can then be passed. Sometimes, the urologist has to place a stent in the ureter to make it wider to help the fragments to pass. Occasionally, the surgeon has to remove a large stone by making an incision in the back and inserting a scope into the kidney. There is no good treatment to dissolve symptomatic stones.

Not all kidney stones cause symptoms. In fact, it’s not unusual to find incidental stones in the kidneys when you have X-rays for an unrelated problem. It’s only when a stone breaks loose and begins to work its way down the ureter that you develop pain.

Fewer than half of people with incidental stones will go on to develop a painful kidney stone attack. Therefore, treatment for asymptomatic stones is optional; I recommend a ‘‘wait and watch’’ approach since treatment can result in a painful attack or cause other complications.

Dr. Jim Mitterando is a family doctor at Cohasset Family Practice and a staff member at South Shore Hospital in Weymouth.

Readers should send questions to: Ask the Doctor, The Patriot Ledger, P.O. Box 699159, Quincy, MA 02269-9159, or by E-mail to his attention at features@ledger.com.

Questions of general interest will be answered in this column. The information in this column is not intended to diagnose individual conditions, and individual replies are not possible. Readers should see their own doctors about specific problems.

Copyright 2003 The Patriot Ledger
Transmitted Tuesday, June 17, 2003