Kidney Stones

According to Darcy Wilding, our Executive Producer Mark Wilding's wife, the pain from a kidney stone? It's worse than childbirth.

Yep, it hurts that badly. It hurts badly enough that Dr. Bailey and Lexie suspected that Thatcher Grey might even be experiencing an episode of rejection from his new liver when he came in with excruciating abdominal pain. The good news: Thatcher's new liver seems to be functioning just fine. The bad news: He has a kidney stone so large that he needs surgery to remove it. Ouch.

What actually is a kidney stone? Is it an actual "stone" per se?

First, it might be helpful to have a brief description of how the kidneys work. Shaped like beans and similar to the size of your fists, the kidneys sit near the middle of your back, below the rib cage, one on each side of the spine. The kidneys basically act as a filter for blood, removing waste products from the body, thus, making urine. They also help to regulate the body's electrolyte levels—vital to the body's functions. Urine drains from the kidneys through a tube (the ureter) into the bladder. Once the bladder fills up, the body feels the need to urinate, and the bladder empties to the outside through another tube (the urethra).

Chemicals in the urine can sometimes crystallize, forming the beginning of a kidney stone (called a nidus). They start very tiny, smaller than a grain of sand, but they have the potential to grow over time up to 1/10 of an inch and larger. Some can even reach the size of golf balls! However, the size of the stone does not matter as much as the location of the stone—on whether it obstructs or prevents urine from draining.

When the stone is in the actual kidney, it does not cause many problems. But once the stone falls into the ureter, it acts like a dam; the kidney will continue to do its job and produce urine, but since it can't drain, pressure builds, and the kidney swells. This pressure causes the horrible physical pain, but it also helps to push the stone down the ureter and into the bladder, where the kidney stone symptoms will soon resolve.

What causes these stones to form?

Doctors cannot agree on one single cause, but they do believe many different factors may play a role. One reason may be linked to heredity. Most stones are comprised of calcium, and the presence of high levels of calcium in the blood can be passed on through generations in a family. Rare hereditary diseases (such as problems metabolizing certain chemicals or renal tubular acidosis) may also predispose people to developing kidney stones.

Certain medications, like antacids with high amounts of calcium and diuretics, can increase the level of calcium in the blood. Other medications associated with kidney stones include excess vitamins A and D, the HIV medicine indinavir, dilantin, and antibiotics (like ceftriaxone and ciprofloxacin).

Geography may even be related! Regional "stone belts" exist in the southern US, where people have an increased risk at suffering from kidney stones. The hot climate combined with poor fluid intake puts people at risk for dehydration and higher concentrations of chemicals in their urine.

Diet may or may not increase one's risk. If a person has formed stones before, he or she may want to actively stay away from foods with high levels of calcium.

How does someone know if they have a kidney stone?

Well, one indicative sign is INTENSE pain. It may come on suddenly, and like with Thatcher, it can come and go as the body attempts to unblock the obstruction. The pain usually will be located in the flank or the side of the mid back, possibly even reaching the groin area. Males have even complained of pain in the testicles or scrotum. The patient struggles with finding a comfortable position amid the waves of pain, often also suffering from nausea, vomiting, and sweating.

Blood may or may not be present in the urine due to irritation of the kidney or ureter. However, blood in the urine may also be a sign of another health problem such as kidney and bladder infections, trauma, or even tumors. However, kidney stones can cause a burning sensation during urination and cloudy or foul-smelling urine.

Doctors will perform a physical examination and sometimes blood work to check for other underlying diseases. Kidney stones are usually diagnosed by a CT scan of the abdomen, which determines the type of stone, its location and size, and whether or not the surrounding organs are affected. An ultrasound can also help diagnose a stone, especially if the patient does not want to risk the radiation from a CT (such as a pregnant woman).

Is surgery always necessary?

Nope, not at all! Most stones actually pass on their own, and patients are simply instructed with symptom control. Doctors usually recommend plenty of oral fluids and Ibuprofen for the pain. However, if one has never experienced a kidney stone before, they probably will want medical assistance. In the emergency department, the patient would receive IV fluids for hydration and medication to help control the nausea and vomiting.

Due to the size and location, some kidney stones cannot pass without extra help. If the stone is located high in the ureter near the kidney, the doctor might suggest lithotripsy, or shock wave therapy to break up the stone into smaller fragments.

If lithotripsy does not seem to be the correct solution, doctors may perform ureteroscopy—a procedure where instruments are threaded into the ureter to allow the doctor to place a stent through the urethra, past the bladder, and into the ureter to bypass the obstructing stone. This stent may be left in the body for a period of time.

Sometimes something called "tunnel surgery" (technically called percutaneous nephrolithotomy) may be performed in which the doctor makes a small incision into the patient's back and creates a narrow tunnel through the skin to the stone inside the kidney. The surgeon then passes an instrument through the tunnel to extract the stone.

How do I make sure I never have to go through the pain of a kidney stone?

Well, prevention can be the best medicine: Always stay hydrated to keep the urine dilute. And try to restrict yourself to only one to two cups of coffee, tea, or a soda a day since the caffeine can cause you to lose fluid more easily. And if you are prone to forming calcium-stones, try limiting foods that are high in oxalate such as chocolate, spinach, beets, and rhubarb.

For more information, please visit:

http://kidney.niddk.nih.gov/kudiseases/pubs/stones_ez/

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