-IBIS-1.5.0-
tx
urinary system
kidney stones/renal colic
diagnoses

definition and etiology

definition:
Calculi formed in the kidneys.

etiology:
Stones in the urinary tract cause the hospitalization of every 1 in 1,000 people in the U.S. each year. Certain areas of the country have a higher incidence and there have been episodes in time when stone epidemics occurred. Almost all kidney stones are made up of either calcium salts (calcium phosphate and oxalates alone are responsible for 75-85% of all stones), uric acid, cystine, or struvite:
• Calcium stones: Are seen chiefly in men and often show family history.
• Uric acid stones: Are found to be only 5-8% of stones and are also seen mostly in men, half of whom will be sufferers of gout, too.
• Cystine stones: Are rare, only 1-3% of all stones.
• Struvite stones: Common in women and often are formed after a UTI caused by the bacterial species Proteus.

Factors involved in the formation of the stones include:
• Increased urinary concentration of crystalloid components. Due to: dehydration, increased rate of excretion of the crystal constituents (a diet high in sugar, coffee and meats, acid foods, for example, that cause the body to lose calcium through the urine).
• Stone formation at normal urinary concentration. Due to: pH changes, urinary stasis, foreign bodies, and the decrease in normal protective means against stone creation.

signs and symptoms

signs and symptoms:
Stones are often asymptomatic.
• Back pain/renal colic: This occurs when one of the stones obstructs either one/more calyces, the renal pelvis, or the ureter. This pain is usually intermittent, excruciating and can cause the person to enter shock. The pain may radiate across the abdomen or into the genitals or the inside of the thigh.
• Hematuria.
• Chills and fever.

lab findings:
• UA: Typically hematuria is present, and crystals can be visible. May see stones.
• Chemical analysis to determine the type of stone present.
• X-ray: Most stones are visible on x-ray.
• Retrograde or intravenous urography/IVP: can show radiolucent or radio-opaque crystals as well as the size of obstruction.
• May see increased urinary calcium.
• Proteinuria and increased urine WBC.

course and prognosis

Small stones often need no treatment except for pain relievers if necessary. In conventional therapy larger stones are treated with surgery or lithotripsy (breakage of the stones into little pieces using ultrasound).

differential diagnosis

• Other causes of acute abdominal pain: e.g. appendicitis
• Kidney infection.
• Causes for the formation of the stone in the first place: idiopathic hypercalciuria; hyperuricouria; primary hyperparathyroidism; distal renal tubular acidosis; hyperoxaluria; idiopathic calcium lithiasis.


footnotes