Calculi, Renal
Calculi, Renal
| DRG Category: | 691 |
| Mean LOS: | 4 days |
| Description: | MEDICAL: Urinary Stones With ESW Lithotripsy With CC or Major CC |
Renal calculi, or nephrolithiasis, are stones that form in the kidneys from the crystallization of minerals and other substances that normally dissolve in the urine. Renal calculi vary in size, with 90% of them smaller than 5 mm in diameter; some, however, grow large enough to prevent the natural passage of urine through the ureter. Calculi may be solitary or multiple. Approximately 80% of these stones are composed of calcium salts. Other types are the struvite stones (which contain magnesium, ammonium, and phosphate), uric acid stones, and cystine stones. If the calculi remain in the renal pelvis or enter the ureter, they can damage renal parenchyma (functional tissue). Larger calculi can cause pressure necrosis. In certain locations, calculi cause obstruction, lead to hydronephrosis, and tend to recur.
Causes
The precise cause of renal calculi is unknown, although they are associated with dehydration, urinary obstruction, calcium levels, and other factors. Patients who are dehydrated have decreased urine, with heavy concentrations of calculus-forming substances. Urinary obstruction leads to urinary stasis, a condition that contributes to calculus formation. Any condition that increases serum calcium levels and calcium excretion predisposes people to renal calculi. These conditions include an excessive intake of vitamin D or dietary calcium, hyperparathyroidism, heredity factors, and immobility. Metabolic conditions such as renal tubular acidosis, elevated serum uric acid levels, and urinary tract infections associated with alkaline urine have been linked with calculus formation. Cystine stones are associated with hereditary renal disease.
Genetic considerations
There are at least 10 different single gene conditions (e.g., primary hyperoxaluria type 1), resulting in familial nephrolithiasis, but these account for less than 2% of persons with renal calculi. Both genetic and environmental factors have been suggested to explain the higher incidence of stone formation in certain geographical areas, including the southeastern United States.
Gender, ethnic/racial, and life span considerations
In the United States, approximately 12% of the male population and 7% of the female population develop a stone at some point in their lives. Calculi occur more often in men than in women, unless heredity is a factor, and occur most often between age 30 to 50. The prevalence is higher in whites and people of Asian ancestry than in other populations. Blacks/African Americans and people from the Mediterranean region have a lower incidence of stones than whites. Individuals living in the South and Southwest in the United States have the highest incidence of stones. When women develop calculi, they are likely to be caused by infection. Children rarely develop calculi. Although the reasons are unknown, in the past 30 years, the prevalence of kidney stones has been increasing. Once a person gets more than one stone, others are likely to develop.
Global health considerations
Although renal calculi occur in all countries, prevalence is lowest in Greenland and parts of Japan. People is Asia have a low lifetime risk as compared to Saudi Arabia and North America. Differences in prevalence are thought to be related to diet.
Assessment
History
Symptoms of renal calculi usually appear when a stone dislodges and begins to travel down the urinary tract and enters the ureter. Establish a history of pain and determine the intensity, duration, and location of the pain. The location of the pain varies according to the position of the stone. The pain usually begins in the flank area but later may radiate into the lower abdomen and the groin. Ask if the pain had a sudden onset. Patients may relate a recent history of hematuria, nausea, vomiting, and anorexia. In cases in which a urinary tract infection is also present, the patient may report chills and fever. Determine the patient’s history to identify risk factors.
Physical examination
The most typical symptoms of renal calculi are flank pain radiating to the groin, fever, hematuria, nausea, and vomiting. Inspection reveals a patient in intense pain who is unable to maintain a comfortable position. Assess the patient for bladder distention. Monitor the patient for signs of an infection such as fever, chills, and increased white blood cell counts. Assess the urine for hematuria. Auscultate the patient’s abdomen for normal bowel sounds. Palpate the patient’s flank area for tenderness. Percussion of the abdominal area is normal, but percussion of the costovertebral angle elicits severe pain.
Psychosocial
Patients with renal calculi may be extremely anxious because of the sudden onset of severe pain of unknown origin. Assess the level of the pain as well as the patient’s ability to cope. Because diet and lifestyle may contribute to the formation of calculi, the patient may face lifestyle changes. Assess the patient’s ability to handle such changes.
Diagnostic highlights
General Comments: The physician uses diagnostic tests to eliminate cholecystitis, peptic ulcers, appendicitis, and pancreatitis as the cause of the abdominal pain.
| Test | Normal Result | Abnormality With Condition | Explanation |
|---|---|---|---|
| Helical computed tomography scan without contrast | Image of normal abdomen | Calculi present | Visualizes size, shape, relative position of stone; contrast not used; with contrast entire urinary collecting system would appear white, masking the stones |
| Kidney-ureter-bladder and abdominal x-rays | No renal stones | Presence of renal stones, most of which are radiopaque | Reveals most renal calculi except cystine and uric acid stones |
| Intravenous (IV) pyelography | Normal anatomy of the kidney/collection system | Obstructing stone | Performed when renal colic is severe and obstruction is suspected |
Other Tests: Other supporting tests include kidney ultrasonography; urinalysis; complete blood count; serum electrolytes; urine culture and sensitivity; serum calcium and phosphorus levels; 24-hour urine for calcium, oxalate, uric acid, sodium, phosphorus, citrate, magnesium, creatinine, total volume
Primary nursing diagnosis
Diagnosis
Altered urinary elimination related to the blockage of ureter with a calculusOutcomes
Urinary elimination; Knowledge: Medication; Symptom severity; Treatment behavior: Illness or injuryInterventions
Urinary elimination management; Medication prescribing; Fluid monitoring; Pain management; Infection control; Tube care: UrinaryPlanning and implementation
Collaborative
Stones less than 4 mm in diameter will likely pass spontaneously (80% chance), whereas stones larger than 8 mm in diameter will likely not pass spontaneously (20% chance). In about 80% of cases, renal calculi of 8 mm or less are treated conservatively with vigorous hydration, which results in the stone passing spontaneously, but supranormal hydration is controversial. Increased fluid intake is ordered orally or IV to flush the stone through the urinary tract. Unless contraindicated, maintain hydration at 200 mL per hour of IV or orally. Strain the patient’s urine to detect stones that are passed so they can be analyzed.
Active medical expulsive therapy (MET) reduces the pain of stone passage and the need for surgery for stones 3 mm to 10 mm in size. Typically, MET includes one to two oral narcotic/acetaminophen tablets every 4 hours and 600 mg to 800 mg ibuprofen every 8 hours for pain, 30 mg nifedipine extended-release tablet once daily to relax the ureteral smooth muscle, and 0.4 mg tamsulosin once daily or 4 mg of terazosin once daily to relax musculature of the ureter and lower urinary tract. Generally, MET is limited to a 10- to 14-day course, when most stones will pass.
For calculi larger than 8 mm or that cannot be passed with conservative treatment, surgical removal is performed. Percutaneous ultrasonic lithotripsy or extracorporeal shock wave lithotripsy (ESWL) uses sound waves to shatter calculi for later removal by suction or natural passage. Calculi in the ureter may be removed with catheters and a cystoscope (ureteroscopy), while a flank or lower abdominal surgical approach may be needed to remove calculi from the kidney calyx or renal pelvis.
Pharmacologic highlights
General Comments: If nausea and vomiting are present, administer antiemetics as ordered. Diuretics may be ordered to prevent urinary stasis.
| Medication or Drug Class | Dosage | Description | Rationale |
|---|---|---|---|
| Analgesia: Primary drugs used are morphine sulfate, butorphanol, and ketorolac (Toradol) | Varies with drug | Narcotics, NSAIDs | To relax the ureter and facilitate passage of stone |
Other Drugs: Antibiotics if infection is present; see earlier discussion of MET
Independent
Initially, the most important nursing interventions concentrate on pain management. Teach relaxation techniques, diversional activities, and position changes. Help promote the passage of renal calculi. Encourage the patient to walk, if possible. Offer the patient fruit juices to help acidify the urine. Teach the patient the importance of proper diet to help avoid a recurrence of the renal calculi, with particular emphasis on adequate hydration and avoiding excessive salt and protein intake.
To reduce anxiety, give the patient and family all pertinent information concerning the treatment plan and any diagnostic tests. Preoperatively, explain the procedure and what to expect afterward. For patients who are undergoing a flank or abdominal incision, teach deep breathing and coughing exercises. Give postoperative care and monitor for signs of infection or pneumonia. Do not irrigate urinary drainage systems without consulting with the physician.
Evidence-Based Practice and Health Policy
Weinbert, A.E., Patel, C. J., Chertow, G.M., & Leppert, J.T. (2014). Diabetic severity and risk of kidney stone disease. European Urology, 65(1), 242–247.
- Dietary and lifestyle factors are associated with the development of renal calculi and other metabolic disorders, such as type II diabetes and obesity.
- Investigators conducted a cross-sectional analysis of adult participants who participated in the 2007–2010 National Health and Nutrition Examination Survey and found that participants with fasting plasma glucose (FPG) levels greater than 126 mg/dl were 2.29 times more likely (95% CI, 1.68 to 3.12) to experience renal calculi than participants with normal FPG levels less than 100 mg/dl.
- They also found that participants with hemoglobin A1C values greater than 6.5% were 2.82 times more likely (95% CI, 1.98 to 4.02) to experience renal calculi than participants with normal values less than 5.7%.
Documentation guidelines
- Response to pain relief measures, degree of pain (location, frequency, duration)
- Record of intake and output, daily weights, vital signs
- Presence of complications: Infection, obstruction, hemorrhage, intractable pain
- Observation of color and consistency of urine, presence of stones