Urolithiasis

Key Points Urolithiasis is the presence of calculi (stones) in the urinary tract. 75% are composed of calcium oxalate or calcium phosphate but may contain other substances such as uric acid. A diet high in calcium is not believed to increase the risk of stone formation unless there is a preexisting metabolic disorder or renal tubular defect. Reoccurrence is increased (35 to 50%) with family history, or first onset before age of 25 years. Most clients can expel stones without invasive procedures. Factors that influence whether a stone will pass spontaneously or not include the composition, size, and location of the stone.

Key Factors The cause of urolithiasis is unknown. There is an increased incidence of urolithiasis in males. Urolithiasis formation is associated with: Slow urine flow with supersaturation of urine Damage to the lining of the urinary tract. Decreased inhibitor substances in the urine. Metabolic defects including: Increased intestinal absorption or decreased renal excretion of calcium. Increased oxalate production (genetic) or ingestion from foods. Increased production or decreased clearance of purines (contributing to increased uric-acid levels). High urine acidity or alkalinity contributes to stone formation. Urinary stasis, urinary retention, immobilization, and dehydration contribute to an environment favorable for stone formation.

Diagnostic Procedures and Nursing Interventions Expected Findings Urinalysis; Increased RBCs, WBCs, and bacteria from urinary stasis. Increased urine turbidity and odor (if urine is infected). Crystals noted on microscopic exam. Abnormal serum calcium, phosphate, and uric-acid levels in the presence of metabolic disorders/defects. Elevated WBC if infection is present. Radiology examination KUB (x-ray of kidney, ureters, bladder), CT scan, or IVP (intravenous pyelogram) CT or MRI is used to identify cystine or uric-acid stones, which cannot be seen on standard x-rays. A renal ultrasound or cystoscopy may confirm diagnosis. US

Therapeutic Procedures and Nursing Interventions Non-surgical Management Extracorporeal shock wave lithotripsy (ESWL) (conscious sedation and ECG monitoring during the procedure). Surgical management Stenting is the placement of a small tube in the ureter during ureteroscopy. Retrograde ureteroscopy uses a basket, forceps, or loop on the end of the ureteroscope to grasp and remove the stone. Percutaneous ureterolithotomy/nephrolithotomy. Open surgery for large or impacted stones Ureterolithotomy (into the ureter) Pyelolithotomy (into the kidney pelvis) Nephrolithotomy (into the kidney)

Nursing Interventions Prepare the client for procedures. Teach the client about the procedures. Report abnormal findings to the provider. Teach the client about ESWL. Strain urine following the procedure. Bruising is normal at the site where waves are applied. Provide preoperative and postoperative care as indicated.

Assessments Severe pain (renal colic) Increases with stone movement. Flank pain suggests stones in the kidney or ureter ( if radiates to the abdomen, scrotum, testes, or vulva is suggestive of stones in the ureters or bladder). Nausea/vomiting Urinary frequency or dysuria (occurs with stones in the bladder) Pallor Diaphoresis Vital signs: Tachycardia, tachypnea, increased or decreased blood pressure with pain Oliguria/anuria (occurs with stones that obstruct urinary flow) Hematuria

NANDA Nursing Diagnoses Acute pain Risk for infection Deficient knowledge Risk for injury (renal) Fear Anxiety

Nursing Interventions Assess/Monitor Pain status Intake and output Urinary pH Administer prescribed medications, such as: Analgesics (opioids , NSAIDS ). Spasmolytic drugs. Antibiotics if infection is present. Strain all urine to check for passage of the stone; save the stone for laboratory analysis.

Nursing Interventions Encourage increased oral intake to 3,000 mL/day unless contraindicated. Administer IV fluids as prescribed. Encourage ambulation????. Provide client education regarding the role of diet and medications in the treatment and prevention of urinary stones. Calcium phosphate Dietary interventions Limit intake of food high in animal protein (Reduction of protein intake decreases calcium precipitation). Limit sodium intake. Reduced calcium intake (dairy products) is individualized. Medications Thiazide diuretics (hydrochlorothiazide) to increase calcium reabsorption Orthophosphates to decrease urine saturation of calcium oxalate Sodium cellulose phosphate to reduce intestinal absorption of calcium

Nursing Interventions Uric acid (urate) Dietary interventions Decrease intake of purine sources (organ meats, poultry, fish, gravies, sardines). Medications to prevent formation of uric acid Potassium or sodium citrate or sodium bicarbonate to alkalinize the urine

Complications and Nursing Implications Treat an obstruction of the ureter and interruption of urinary flow as an emergency, and report it immediately. Monitor for signs of infection, and report abnormal findings. Monitor for signs of urine outflow obstruction (hydronephrosis) of the affected kidney, and report abnormal findings. Renal failure (For information, refer to chapter 50, Renal Failure.)