Nephrolithiasis: The process of forming a kidney stone, a stone in the kidney (or lower down in the urinary tract).

Kidney stones are a common cause of blood in the urine and pain in the abdomen, flank, or groin. Kidney stones occur in 1 in 20 people at some time in their life.

The development of the stones is related to decreased urine volume or increased excretion of stone-forming components such as calcium, oxalate, urate, cystine, xanthine, and phosphate. The stones form in the urine collecting area (the pelvis) of the kidney and may range in size from tiny to staghorn stones the size of the renal pelvis itself.

The cystine stones (below) compared in size to a quarter (a U.S. $0.25 coin) were obtained from the kidney of a young woman by percutaneous nephrolithotripsy (PNL), a procedure for crushing and removing the dense stubborn stones characteristic of cystinuria.

The pain with kidney stones is usually of sudden onset, very severe and colicky (intermittent), not improved by changes in position, radiating from the back, down the flank, and into the groin. Nausea and vomiting are common.

Factors predisposing to kidney stones include recent reduction in fluid intake, increased exercise with dehydration, medications that cause hyperuricemia (high uric acid) and a history of gout.

Treatment includes relief of pain, hydration and, if there is concurrent urinary infection, antibiotics.

The majority of stones pass spontaneously within 48 hours. However, some stones may not. There are several factors which influence the ability to pass a stone. These include the size of the person, prior stone passage, prostate enlargement, pregnancy, and the size of the stone. A 4 mm stone has an 80% chance of passage while a 5 mm stone has a 20% chance. If a stone does not pass, certain procedures (usually by a urology specialist doctor) may be needed.

The process of stone formation, nephrolithiasis, is also called urolithiasis. "Nephrolithiasis" is derived from the Greek nephros- (kidney) lithos (stone) = kidney stone "Urolithiasis" is from the French word "urine" which, in

turn, stems from the Latin "urina" and the Greek "ouron" meaning urine = urine stone. The stones themselves are also called renal caluli. The word "calculus" (plural: calculi) is the Latin word for pebble

Causes --Kidney stones can form when urine contains too much of certain substances. These substances can create small crystals that become stones.The biggest risk factor for kidney stones is dehydration.Kidney stones may not produce symptoms until they begin to move down the tubes (ureters) through which urine empties into the bladder. When this happens, the stones can block the flow of urine out of the kidneys. This causes swelling of the kidney or kidneys, causing pain. The pain is usually severe.Kidney stones are common. A person who has had kidney stones often gets them again in the future. Kidney stones often occur in premature infants.Some types of stones tend to run in families. Certain kinds of stones can occur with bowel disease, ileal bypass for obesity, or renal tubule defects.There are different types of kidney stones. The exact cause depends on the type of stone.

Calcium stones are most common. They occur more often in men than in women, and usually appear between ages 20 - 30. They are likely to come back. Calcium can combine with other substances, such as oxalate (the most common substance), phosphate, or carbonate to form the stone. Oxalate is present in certain foods. Diseases of the small intestine increase the risk of forming calcium oxalate stones.

Cystine stones can form in people who have cystinuria. This disorder runs in families and affects both men and women.

Struvite stones are mostly found in women who have a urinary tract infection. These stones can grow very large and can block the kidney, ureter, or bladder.

Uric acid stones are more common in men than in women. They can occur with gout or chemotherapy.

Symptoms

The main symptom is severe pain that starts suddenly and may go away suddenly:

Pain may be felt in the belly area or side of the back.Pain may move to groin area (groin pain) or testicles (testicle pain).Abnormal urine color.Blood in the urine.Chills.Fever.Nausea.Vomiting

Exams and Tests Pain can be severe enough to need narcotic pain relievers. The belly area (abdomen) or back might feel tender to the touch.Tests for kidney stones include:

Analysis of the stone to show what type of stone it is

Uric acid level Urinalysis to see crystals and

red blood cells in urine

Tests may show high levels of calcium, oxylate, or uric acid in the urine or blood.

Treatment

The goal of treatment is to relieve symptoms and prevent further symptoms. (Kidney stones that are small enough usually pass on their own.) Treatment varies depending on the type of stone and how severe the symptoms are. People with severe symptoms might need to be hospitalized.When the stone passes, the urine should be strained and the stone saved and tested to determine the type.Drink at least 6 - 8 glasses of water per day to produce a large amount of urine. Some people might need to get fluids through a vein (intravenous).Pain relievers can help control the pain of passing the stones (renal colic). For severe pain, you may need to take narcotic pain killers or nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen.Depending on the type of stone, your doctor may prescribe medicine to decrease stone formation or help break down and remove the material that is causing the stone. Medications can include:

Allopurinol (for uric acid stones)

Antibiotics (for struvite stones)

Diuretics Phosphate solutions Sodium bicarbonate or

sodium citrate (which make the urine more alkaline)

Surgery is usually needed if:

The stone is too large to pass on its own

The stone is growing

The stone is blocking urine flow and cuasing an infection or kidney damage

Today, most treatments are much less invasive than in the past.

Extracorporeal shock-wave lithotripsy is used to remove stones slightly smaller than a half an inch that are located near the kidney. This method uses ultrasonic waves or shock waves to break up stones. Then, the stones leave the body in the urine.

Percutaneous nephrolithotomy is used for large stones in or near the kidney, or when the kidneys or surrounding areas are incorrectly formed. The stone is removed with an endoscope that is inserted into the kidney through a small opening.

Ureteroscopy may be used for stones in the lower urinary tract.

Standard open surgery (nephrolithotomy) may be needed if other methods do not work or are not possible.

Outlook (Prognosis)

Kidney stones are painful but usually can be removed from the body without causing permanent damage. They tend to return, especially if the cause is not found and treated.

Possible Complications

Decrease or loss of function in the affected kidney

Kidney damage , scarring Obstruction of the ureter

(acute unilateral obstructive uropathy)

Recurrence of stones Urinary tract infection

When to Contact a Medical Professional

Call your health care provider if you have symptoms of a kidney stone.

Also call if symptoms return, urination becomes painful, urine output decreases, or other new symptoms develop.

Prevention

If you have a history of stones, drink plenty of fluids (6 - 8 glasses of water per day) to produce enough urine. Depending on the type of stone, you might need to take medications or other measures to prevent the stones from returning.

You may need to change your diet to prevent some types of stones from coming back.

ENERIC NAME: Potassium Citrate

BRAND NAME:Acalka

CLASSIFICATION:Antiurolithic

DOSAGE:10 mEq

MECHANISM OF ACTION:The aim of the treatment is to restore the level of the urinary citrate and to increase the pH of urine to 6-7, and to this end, the dosage pattern are:- In patients with slight hypocitraturia start the treatment with a dose of 30mEq (3 tabs/day, divided into 3 takings daily. It is recommended to take the tablets 30 minutes after meals. Approx 24 hrs after having started the treatment, make a determination of urinary citrate and pH, and adjust the dose in accordance with the needs of the patient. If necessary, the dose can be increased, though it is not advisable to exceed the dose of 100 mEq (10 tablets)/day.

INDICATION:-Treatment of patients with renal lithiasis and hypocitraturia, chronic formers of calcium oxalate, phospate calculia.- Uric acid lithiasis alone or accompanied by calcium lithiasis

CONTRAINDICATIONS:- Renal insufficiency¨ Persistent alkaline urinary infections- Obstruction of the urinary tract- Hyperpotassemia¨Adrenal insufficiency- Respiratory or metabolic alkalosis- Active peptic ulcer- Intestinal obstruction- Patients submitted to anticholinergic therapy- Patients with slow gastric emptying.

SIDE EFFECTS/ ADVERSE EFFECTS:

- Slight gastrointestinal disorders may appear which can be palliated by means of the joint administration of food.

NURSING IMPLICATIONS/RESPONSIBILITIES:- The tablets must not be masticated or diluted. The active component of Acalka is contained with a porous wax matrix. As this was matrix is insoluble, it can be eliminated in visible form in the feces. The active component, however, has been released in the gastrointestinal tract.- Must not be administered to patients receiving potassium-sparing diuretics (traimterene, spirolactone, or amyloride).- It is advisable to carry out an evaluation of electrolytes (Na-K-Cl) and CO2, creatinine and hemogram every 4 hrs.- It is recommended that the patients in treatment with Acalka follow a diet w/o salt and increase the intake of fluids.- The recommended treatment in case of hyperpotassemia is: IV administratioin f 10% dextrose solution, containing 10-12 units of insulin/1000ml. Correction of the possible acidosis with IV sodium bicarboate and hemodialysis or peritoneal dialysis.