2. RENALCALCULI
Renal calculi can form anywhere in the urinary tract, but
they most commonly develop in the renal pelvis or calices.
Calculi form when substances that are normally dissolved in the
urine (such as calcium oxalate, calcium phosphate, uric acid,
cystine, and magnesium ammonium phosphate) precipitate.
Renal calculi vary in size and may be solitary or multiple
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7. CAUSESOF RENALCALCULI
The exact cause of renal calculi is unknown, but predisposing factors include:
DEHYDRATION -Decreased water excretion concentrates calculus-forming substances.
INFECTION -Infected, scarred tissue may be a site for calculus development. In addition, infected
calculi (usually magnesium ammonium phosphate or staghorn calculi) may develop if bacteria serve
as the nucleus in calculus formation. Struvite calculus formation commonly results from Proteus
infections, which may lead to destruction of renal parenchyma.
8. URINEpH CHANGES
Consistently acidic or alkaline urine may provide a favorable medium for calculus formation, especially
for magnesium ammonium phosphate or calcium phosphate calculi.
OBSTRUCTION
Urinary stasis allows calculi constituents to collect and adhere, forming calculi. Obstruction also
encourages infection, which compounds the obstruction.
IMMOBILIZATION
Immobility from spinal cord injury or other disorders allows calcium to be released into the circulation
and, eventually, to be filtered by the kidneys.
9. METABOLICFACTORS
Hyperparathyroidism, renal tubular acidosis, elevated uric acid (usually with gout), defective metabolism
of oxalate, a genetically caused defect in metabolism of cystine, and excessive intake of vitamin D or dietary
calcium may predispose a person to renal calculi.
FAMILYHISTORYOF RENALCALCULI
Other Factors Other possible causes of renal calculi include multiple myeloma, Paget disease, bone cancer,
Cushing disease or syndrome (loss of bone calcium), and milk–alkali syndrome.
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11. SIGNSANDSYMPTOMS
• Severe pain that travels from the costovertebral angle, to the flank, to the upper
outer quadrant of the abdomen on the affected side, and then to the suprapubic
region and external genitalia (classic renal colic)
• Pain intensity that fluctuates and may be excruciating at its peak
• Constant, dull pain (in the renal pelvis and calices)
• Nausea
• Vomiting
• Fever and chills
• Hematuria
• Abdominal distention
13. Treatment
Vigorous hydration (more than 3 qt [3 L]/24 hr) to encourage natural passage of small calculi
Antimicrobial agents (for infection, varying with the cultured organism)
Nonsteroidal anti-inflammatory drugs such as ketorolac (proven effective for renal coli
pain)Analgesics, such as morphine (for pain)
Diuretics to prevent urinary stasis and further calculus formation (thiazides decrease calcium
excretion into the urine)
Methenamine mandelate to suppress calculus formation (for infection)
14. Diet of adequate calcium intake, commonly combined with oxalate-binding cholestyramine (for
absorptive hypercalciuria)
Parathyroidectomy (for hyperparathyroidism)Allopurinol (Alloprim) (for uric acid calculi)
Daily oral doses of ascorbic acid to acidify urine
Percutaneous ultrasonic lithotripsy (PUL) and extracorporeal shock-wave lithotripsy (ESWL) (for
calculi too large for natural passage)
Ureteroscopy (for stones of 1 to 2 cm)Stents to maintain patency of the ureters and to facilitate
urine passage
Stents to maintain patency of the ureter and to facilitate urine passage.
15. NURSING CONSIDERATIONS
To aid diagnosis, maintain a 24- to 48-hour record of urine pH using Nitrazine pH paper.
Strain all urine through gauze or a tea strainer, and save all solid material recovered for
analysis.
To facilitate spontaneous passage of calculi, encourage the patient to walk, if possible.Also
encourage fluids to maintain a urine output of 3,000 to 4,000 mL/24 hr. (Urine should be
very dilute and colorless.)
If the patient cannot drink the required amount of fluid, give supplemental IVfluids.
16. Record intake and output and daily weight to assess fluid status and renal function.
Medicate for pain and evaluate response.
If the patient had calculi surgically removed, he probably has an indwelling catheter or a nephrostomy
tube. Unless one of his kidneys was removed, expect bloody drainage from the catheter. Immediately
report excessive drainage or a rising pulse rate, and symptoms of hemorrhage. Use a sterile technique
when changing dressings or providing catheter care.
Watch for signs of infection, such as a rising fever or chills, and give antibiotics as ordered
17. TEACHINGABOUT RENALCALCULI
•Encourage increased fluid intake. If appropriate, show the patient how to check his urine pH, and
instruct him to keep a daily record. Tell him to immediately report symptoms of acute obstruction,
such as pain or an inability to void.
•Urge the patient to follow a prescribed diet and comply with drug therapy to prevent recurrence of
calculi. For example, if a hyperuricemic condition caused the patient’s calculi, teach him which foods
are high in purine (organ meats, cream). For calcium oxalate calculi, teach him to avoid foods high in
oxalates (such as spinach, Swiss chard, chocolate, peanuts, and pecans).
18. If surgery is necessary, supplement and reinforce the physician’s teaching. The patient is apt to be
fearful, especially if he requires kidney removal, so emphasize that the body can adapt well to one
kidney. If he is having an abdominal or flank incision, teach deep-breathing and coughing
exercises.
Explain how to strain urine and the importance of retaining any stones to submit for chemical
analysis.