Urolithiasis or Urinary Calculi S Refers to the

Urolithiasis or Urinary Calculi

S Refers to the presence of stones in the urinary system S Stones, or calculi, are formed in the urinary tract from the kidney to bladder by the crystallization of substances excreted in the urine.

Pathophysiology and Etiology 1. Most stones (75%) are composed mainly of calcium oxalate crystals; the rest are composed of calcium phosphate salts, uric acid, struvite (magnesium, ammonium, and phosphate)

2. Causes and predisposing factors. S Hypocalcemia and hypercalciuria caused by hyperparathyroidism, renal tubular acidosis, multiple myeloma, and excessive intake of vitamin D, milk and alkali. S Chronic dehydration, Poor fluid intake, and immobility. S Diet high in purines and abnormal purine metabolism. (Hyperuricemia and gout) S Genetic predisposition for urolithiasis / genetic disorders. (Cystinuria)

SChronic infection with urea – splitting bacteria (Proteus vulgaris) S Chronic obstruction with stasis of urine, foreign bodies within the urinary tract. S Excessive oxalate absorption in inflammatory bowel disease and bowel resection or ileostomy. S Living in mountainous, desert, or tropical areas.

3. Stones may be found anywhere in the urinary system and vary in size from mere granular deposits (called sand or gravel) to bladder stones the size of an orange. 4. Three out of four patients with stones are men; in both sexes, the peak age of onset is between ages 20 and 40. 5. Most stones migrate downward (causing severe colicky pain) and are discovered in the lower ureter. Spontaneous stone passage can be anticipated in 80% of pts with urolithiasis.

6. Some stones may lodge in the renal pelvis, ureters, or bladder neck causing obstruction, edema, secondary infection and, in some cases, nephron damage. 7. People who have had two stones tend to have recurrences.

Clinical Manifestations S Pain pattern depends on site of obstruction. a. Renal stones produce an increase in hydrostatic pressure and distention of the renal pelvis and proximal ureter causing renal colic. Pain relief is immediate after stone passage. b. Large ureteral stones produce symptoms or obstruction as they pass down the ureter (ureteral colic)

c. Bladder stones produce symptoms similar to cystitis. S Obstruction – stones blocking the flow of urine will produce symptoms of UTI; chills and fever. S GI symptoms include nausea, vomiting, diarrhea, abdominal discomfort – due to renointestinal reflexes and shared nerve supply (celiac ganglion) between the ureters and intestine.

Assessment Factors Specific to Patients with Urinary calculus Diseases Present & Past medical history Medical treatment & surgical procedures on and outside GU tract. UTIs Periods of prolonged illness with mobilization / dehydration Gout Malignant neoplasms Endocrinopathies

Family histories Present & Past geographic residences Age Sex Occupation Dietary habits Fluid Intake Vitamin Intake Medication History Steroids Alkalizing agents Pain Location Intensity Character & Quality Chronology Pain response Psychological Behavioral Affective

Surgical Intervention for Urolithiasis Surgery Open Procedures Nephrolithotomy Nephrectomy (partial / total) Pyelolithotomy Ureterolithotomy Custolithectomy Litholapaxy Indications Crushing of urolithiasis with lithotrite; small stone fragment can then be flushed from UT

Closed procedures Percutaneous Ultrasound used to Ultrasonic lithotripsy fragment large calculus (PUL) so fragments can be mechanically removed or flushed out of the system. Extracorporeal shock wave lithotripsy (ESWL) Patient is placed in tank of water through which shock waves are sent to pulverize stone that is then passed during urination.

Nursing Diagnoses Acute pain related to inflammation, obstruction, and abrasions of UT by migration of stones. Impaired Urinary Elimination related to blockage of urine flow by stones. Risk for Infection related to obstruction of urine flow and instrumentation during treatment.

Nursing Interventions Controlling Pain 1. Give opioid analgesic (usually IV or IM) until cause of pain can be removed. a. Monitor pt closely for increasing pain; may indicate inadequate analgesia. b. Very large doses of opioids are typically required to relieve pain, so monitor for respiratory depression and drop in blood pressure.

2. Encourage pt to assume position that brings some relief. 3. Reassess pain frequently. 4. Administer antiemetics (IM or rectal suppository) as indicated for nausea.

1. 2. 3. Maintaining Urine Flow Administer fluids orally or IV (if vomiting) to reduce concentration of urinary crystalloids and ensure adequate urine output. Monitor total urine output and patterns of voiding. Report oliguria or anuria. Strain all urine through strainer or gauze to harvest the stone. Uric acid stones may crumble. Crush clots, and inspect sides of urinal / bedpan for clinging stones / fragments.

Patient Education and Health Maintenance 1. 2. 3. Recovery from surgical Interventions for Stone Disease Encourage fluids to accelerate passing of stone particles. Teach about analgesics that still may be necessary for colicky pain, which may accompany passage of stone debris. Warn that some blood may appear in urine for several weeks.

4. Encourage frequent walking to assist in passage of stone fragments. 5. Teach pt to strain urine through a coffee filter.

6. For outpatient treatment, the patient may use a coffee filter to strain urine. 7. Help pt to walk, if possible, because ambulation may help move the stone through the UT. I Avoid over hydration, which may result in increased distension at stone location, causing an increase in pain and associated symptoms.

Prevention of Recurrent Stone Formation 1. For pts with calcium oxalate stones a. Instruct on diet – avoid excess of calcium and phosphorus; maintain a low sodium diet (sodium restriction decreases amount of calcium absorbed in intestine) b. Teach purpose of drug therapy – thiazide diuretics to reduce urine calcium excretion, allopurinol therapy to reduce uric acid concentration.

2. For pts with uric acid stones a. Teach methods to alkalinize urine to enhance urate solubility. b. Instruct on testing urine p. H. c. Teach purpose of taking allopurinol – to lower uric acid concentration. d. Provide information about reduction of dietary purine intake (low protein – red meat, fish, fowl)

3. For pts with infection (Struvite) stone a. Teach signs and symptoms of urinary infection; encourage him to report infection immediately; must be treated vigorously. b. Try to avoid prolonged periods of recumbency – slows renal drainage and alters calcium metabolism.

c. Teach pt with drug therapy with D – Pencillamine (Depen) – to lower cystine concentration, or dissolution by direct irrigation with thiol derivatives. d. Explain importance of maintaining drug therapy consistently. 4. For all pts with stone disease, a. Explain need for consistently increased fluid intake (24 – hour urinary output greater than 2 l) – lowers the concentration of substances involved in stone formation.

i. ii. iii. b. Drink enough fluids to achieve a urinary volume of 2000 – 3000 ml or more every 24 hours. Drink larger amounts during periods of strenuous exercise, if pt perspires freely. Take fluids in evening to guarantee a high urine flow during the night. Encourage a diet low in sugar and animal proteins – refined carbohydrates appear to lead to hypercalciuria and urolithiasis; animal proteins increase urine excretion of calcium, uric acid, and oxalate.

c. Increase consumption of fiber – inhibits calcium and oxalate absorption. d. Save any stone passed for analysis. (Only pts with more than one episode of urolithiasis are advised to have a metabolic evaluation. ) e. Can discontinue urine straining 72 hours after symptoms resolve.

Management 1. If small stone (< 4 mm) and able to treat as out pt, 80% will pass stone spontaneously with hydration, pain control, and reassurance. 2. Hospitalized for intractable pain, persistent vomiting, high – grade fever, obstruction with infection, and solitary kidney with infection.