Authors

  1. Solo, Stacie BSN, RN
  2. Sharp, Matthew BSN, RN, CEN
  3. Devendorf, Carol MSN, RN, CCRN, CEN
  4. Murray, Charlotte BSN, RN

Article Content

Nephrolithiasis, better known as renal calculi (kidney stones), is commonly seen in the ED. Patients who present with renal calculi are at risk for urethral and kidney damage if not identified correctly. That's why it's important to be able to recognize signs and symptoms of acute nephrolithiasis and be knowledgeable about treatment modalities for appropriate and expeditious care.

  
Figure. No caption a... - Click to enlarge in new windowFigure. No caption available.

Pathophysiology

The causes of renal calculi are dependent on the source. For example, calcium stones are caused by an increased calcium level due to decreased urine output. Struvite stones are caused by a recent infection, such as a urinary tract infection. Uric acid stones are caused by high circulating protein levels, along with decreased fluid intake that comes along with many of the fad high-protein diets. Cystine stones have a hereditary component and stem from kidneys that excrete excessive amounts of amino acids. The commonality between the types of renal calculi is decreased intake of fluids, decreased output of fluids, and unbalanced or poor diets (see Picturing renal calculi).

 

Signs and symptoms

Renal calculi often cause severe pain, which is known as renal colic. This pain may wax and wane, although it can be intense at times, causing restlessness. Calculi may travel from the kidney into the ureters. Symptoms may not occur until the calculus begins to move down the ureters. The ureters are small and often the calculus is too large to pass easily into the bladder. During the passage down the ureter, the calculus causes spasms and irritation, which causes blood to appear in the urine. However, if the calculus is small, the patient may not have any pain or symptoms as it passes through the ureters into the bladder.

 

Other common symptoms of renal calculi include:

 

* nausea

 

* vomiting

 

* fever

 

* chills

 

* discolored or foul-smelling urine

 

* urinary frequency or retention

 

* abdominal pain, groin pain, or back pain that's typically on one side.

 

 

Urinary obstruction, in which the calculus blocks the flow of urine, can lead to pyelonephritis and kidney damage.

 

Diagnostics

Patients with renal calculi usually present with colicky flank pain; however, the pain can present in the groin, urethra, and even the abdomen. Therefore, diagnosing renal calculi is done by urinalysis, which may show hematuria and can indicate the type of crystal that's causing the calculus buildup, and an abdominal computerized tomography (CT) scan without contrast. The importance of ordering the CT scan without contrast is due to the contrast obliterating the view of the calculi, which can cause them to be undiagnosed.

 

To determine the patient treatment plan, a clinical evaluation includes analyzing all test results, consideration of the patient's presentation, and a comprehensive history. An important piece to include in the clinical evaluation is whether this is a first-time presentation of renal calculi versus a repeated occurrence. This helps guide the patient's care plan more efficiently and allows for a more thorough workup, especially if the patient has a history of calculi.

  
Figure. Picturing re... - Click to enlarge in new windowFigure. Picturing renal calculi

Treatment

Patients with acute renal calculi are at risk for severe pain, volume deficit due to nausea and vomiting, and impaired urinary elimination related to ureteral obstruction or acute kidney injury. Pain management is a primary consideration for the patient presenting with renal calculi.

 

Pain in adult and adolescent patients without cognitive impairments should be assessed using a 0-to-10 scale. Other pain scales that may be used for pediatric patients and those with cognitive deficits include the Neonatal Facial Coding System; the Pain Assessment Inventory for Neonates; the Wong-Baker FACES Pain Rating Scale; the Facial Affective Scale; the Face, Legs, Activity, Cry, and Consolability Pain Assessment Tool; the Behavioral Pain Scale; and the Pain Behavior Assessment Tool.

 

Patients who are having less pain may be given oral analgesics. Nonsteroidal anti-inflammatory drugs or opioids, either singularly or in combination, may be prescribed for patients having more severe pain. Antiemetics, along with I.V. hydration, may be indicated to manage nausea and vomiting. A beta-blocker or a calcium channel blocker may be prescribed to help ureteral dilation and allow smaller calculi to pass.

 

If the calculus is determined to be too large to pass, other measures are necessary. Extracorporeal shock wave lithotripsy is a procedure that utilizes sound waves to break up larger calculi. Alternatively, ureteroscopy utilizes a catheter equipped with a camera to be passed through the urethra so that the healthcare provider can remove or break up the calculus and place a stent if necessary. Surgery, involving general anesthesia and a 1- to 2-day hospital stay, is also an option to remove very large calculi.

 

Drugs prescribed to prevent the formation of renal calculi include thiazide diuretics, allopurinol, and citrates. Acetohydroxamic acid is the only drug approved and prescribed for the management of infectious renal calculi.

 

Nursing interventions

Immediate collection of urine for analysis to check for hematuria and/or crystals in the urine is helpful in determining the possibility of renal calculi. Microscopic hematuria is present in 85% of patients with renal calculi, whereas gross hematuria is present in 30% of cases. Assess and document urine color, pain with urination, and/or dysuria. The primary nursing intervention for patients experiencing renal calculi is pain control. Assess the onset, location, radiation, duration, scale, and intensity of the patient's pain. Rapid I.V. access allows you to quickly administer analgesics as prescribed.

 

These patients need to be frequently reassessed to ensure the effectiveness of analgesic therapy. Patients who have episodic or recurrent vomiting should be assessed for symptoms of dehydration, including tachycardia, hypotension, and dizziness. I.V. rehydration can be accomplished with isotonic fluids, such as 0.9% sodium chloride solution, along with concurrent antiemetic medications. If the patient is receiving an opioid medication, monitor for hypotension, low oxygen saturation, and low respiratory rate.

 

Patient education

The primary objective of patient education is geared toward helping patients manage their existing calculi and/or prevent future occurrences. Patients discharged from the ED should be sent home with a strainer and specimen cup. All urine should be strained and any calculus or fragment should be brought to the healthcare provider so that it can be sent for analysis. Patients with existing calculi may be sent home with prescriptions for analgesics and antiemetic medications. Increasing fluid intake may help flush calculi, reduce the chances of fluid and electrolyte imbalance, and decrease the possibility of future calculus formation.

 

Dietary modifications, such as avoiding foods that are known to raise urinary oxalate excretion, including raspberries, figs, plums, spinach, rhubarb, beets, nuts, tea, wheat bran, chocolate, and high amounts of vitamin C, may also be suggested to limit the formation of certain types of calculi. Patients are encouraged to increase their water intake to six 8-oz glasses per day to ensure a urine output of approximately 2.5 L/day. Patients should also be advised to limit sodium intake and animal proteins, such as canned or processed foods, beef, chicken, pork, eggs, fish and shellfish, milk, cheese, and other dairy products.

 

A return to comfort

With the high prevalence of patients presenting with renal calculi, it's important to recognize signs and symptoms promptly. Providing expeditious treatment is a key for patient comfort, along with education to aid in reduction of future episodes.

 

cheat sheet

Signs and symptoms

 

* Renal colic

 

* Nausea

 

* Vomiting

 

* Fever

 

* Chills

 

* Discolored or foul-smelling urine

 

* Urinary frequency or retention

 

* Abdominal pain, groin pain, or back pain (typically on one side)

 

REFERENCES

 

American Urological Association. Medical management of kidney stones. https://http://www.auanet.org/education/guidelines/management-kidney-stones.cfm.

 

Chitnis SS, Kabba K, Kulkarni M. Nephrolithiasis: diagnosis and management in the ED. http://www.emdocs.net/nephrolithiasis-diagnosis-management-ed/.

 

Manjunath A, Skinner R, Probert J. Assessment and management of renal colic. BMJ. 2013;346:f985.

 

Mayo Clinic. Kidney stones. http://www.mayoclinic.org/diseases-conditions/kidney-stones/home/ovc-20319559.

 

Sakhaee K, Maalouf NM, Sinnott B. Clinical review. Kidney stones 2012: pathogenesis, diagnosis, and management. J Clin Endocrinol Metab. 2012;97(6):1847-1860.

 

Taylor EN, Fung TT, Curhan GC. DASH-style diet associates with reduced risk for kidney stones. J Am Soc Nephrol. 2009;20(10):2253-2259.

 

Venable E. Pain assessment in persons with cognitive impairment. http://emedicine.medscape.com/article/2113960-overview#a5.