Introduction
Background
Acute passage of a kidney stone from the renal pelvis through the ureter gives rise to pain at times so excruciating that it has been likened to the discomfort of childbirth. The often sudden, extremely painful episode of renal colic prompts more than 450,000 visits to EDs annually and places emergency physicians on the front line of management of acute nephrolithiasis. ED management is focused on excluding other serious diagnoses and providing adequate pain relief.
Pathophysiology
Most calculi arise in the kidney when urine becomes supersaturated with a salt that is capable of forming solid crystals. Symptoms arise as these calculi become impacted within the ureter as they pass toward the urinary bladder.
Frequency
United States
The lifetime prevalence of nephrolithiasis is approximately 12% for men and 7% for women in the United States. Recurrence rates after the first stone episode are 14%, 35%, and 52% at 1, 5, and 10 years, respectively. An increased incidence has been noted in the southeastern United States, prompting the term "stone belt" for this region of the country.
International
Nephrolithiasis occurs in all parts of the world, with a lower lifetime risk of 2-5% in Asia, 8-15% in the West, and 20% in Saudi Arabia.
Mortality/Morbidity
- Approximately 80-85% of stones pass spontaneously.
- Approximately 20% of patients require hospital admission because of unrelenting pain, inability to retain enteral fluids, proximal urinary tract infection (UTI), or inability to pass the stone.
- A ureteral stone associated with obstruction and upper UTI is a true urologic emergency. Complications include perinephric abscess, urosepsis, and death. Immediate involvement of the urologist is essential.
Race
- White males are affected 3-4 times more often than African American males.
- African Americans have a higher incidence of infected ureteral calculi than whites.
Sex
- The male-to-female ratio is approximately 3:1.
- Female patients have a higher incidence of infected hydronephrosis.
Age
Peak onset of symptomatic nephrolithiasis is in the third and fourth decades of life.
- Beware of the patient older than 60 years with an apparent first kidney stone. Consider the possibility of symptomatic abdominal aortic aneurysm (AAA) in the older patient, and rule out this possibility before pursuing the diagnosis of nephrolithiasis. Use bedside ultrasonography if the patient's condition is potentially unstable. CT scan is a reasonable alternative in the patient in stable condition.
- Nephrolithiasis in children is rare; approximately 5-10 children aged 10 months to 16 years are seen annually for the condition at a typical US pediatric referral center.
Clinical
History
Most calculi originate within the kidney and proceed distally, creating various degrees of urinary obstruction as they become lodged in narrow areas, including the ureteropelvic junction, pelvic brim, and ureterovesical junction. Location and quality of pain are related to position of the stone within the urinary tract. Severity of pain is related to the degree of obstruction, presence of ureteral spasm, and presence of any associated infection.
- Stones obstructing the ureteropelvic junction may present with mild-to-severe deep flank pain without radiation to the groin, due to distension of the renal capsule.
- Stones impacted within the ureter cause abrupt, severe, colicky pain in the flank and ipsilateral lower abdomen with radiation to the testicles or the vulvar area. Intense nausea, with or without vomiting, usually is present.
- Stones lodged at the ureterovesical junction also may cause irritative voiding symptoms, such as urinary frequency and dysuria.
- Calculi that have entered the bladder are usually asymptomatic and are passed relatively easily during urination.
- Rarely, a patient reports positional urinary retention (obstruction precipitated by standing, relieved by recumbency), which is due to the ball-valve effect of a large stone located at the bladder outlet.
Physical
The classic patient with renal colic is writhing in pain, pacing about, and unable to lie still, in contrast to a patient with peritoneal irritation, who remains motionless to minimize discomfort.
- Fever is not part of the presentation of uncomplicated nephrolithiasis. If present, suspect infected hydronephrosis, pyonephrosis, or perinephric abscess.
- The most common finding in ureterolithiasis is flank tenderness due to the dilation and spasm of the ureter from transient obstruction as the stone passes from the kidney to the bladder.
- Abdominal examination usually is unremarkable. Bowel sounds may be hypoactive, a reflection of mild ileus, which is not uncommon in patients with severe, acute pain.
- In patients older than 60 years with no prior history of renal stones, the emergency physician should look carefully for physical signs of AAA (see Aneurysm, Abdominal).
- Testicles may be painful but should not be very tender and should appear normal.
Causes
The formation of the 4 basic chemical types of renal calculi is associated with more than 20 underlying etiologies. Stone analysis, together with serum and 24-hour urine metabolic evaluation, can identify an etiology in more than 95% of patients. Specific therapy can result in a remission rate of more than 80% and can decrease the individual recurrence rate by 90%. Therefore, emergency physicians should stress the importance of urologic follow-up, especially in patients with recurrent stones, solitary kidneys, or previous kidney or stone surgery and in all children.
- Calcium stones (75%): Calcium oxalate, calcium phosphate, and calcium urate are associated with the following disorders:
- Hyperparathyroidism - Treated surgically or with orthophosphates if the patient is not a surgical candidate
- Increased gut absorption of calcium - The most common identifiable cause of hypercalciuria, treated with calcium binders or thiazides plus potassium citrate
- Renal calcium leak - Treated with thiazide diuretics
- Renal phosphate leak - Treated with oral phosphate supplements
- Hyperuricosuria - Treated with allopurinol, low purine diet, or alkalinizing agents such as potassium citrate
- Hyperoxaluria - Treated with dietary modification, oxalate binders, vitamin B-6, or orthophosphates
- Hypocitraturia - Treated with potassium citrate
- Hypomagnesuria - Treated with magnesium supplements
- Struvite (magnesium ammonium phosphate) stones (15%)
- Struvite stones are associated with chronic UTI with gram-negative rods capable of splitting urea into ammonium, which combines with phosphate and magnesium.
- Usual organisms include Proteus, Pseudomonas, and Klebsiella species. Escherichia coli is not capable of splitting urea and, therefore, is not associated with struvite stones.
- UTI does not resolve until stone is removed entirely.
- Urine pH is typically greater than 7.
- Uric acid stones (6%): These are associated with urine pH less than 5.5, high purine intake (eg, organ meats, legumes, fish, meat extracts, gravies), or malignancy (ie, rapid cell turnover). Approximately 25% of patients with uric acid stone have gout.
- Cystine stones (2%)
- Cystine stones arise because of an intrinsic metabolic defect resulting in failure of renal tubular reabsorption of cystine, ornithine, lysine, and arginine.
- Urine becomes supersaturated with cystine with resultant crystal deposition.
- These are treated with low-methionine diet (unpleasant), binders such as penicillamine or a -mercaptopropionylglycine, large urinary volumes, or alkalinizing agents.
- Drug-induced stone disease: A number of medications or their metabolites can precipitate in urine causing stone formation. These include indinavir; atazanavir; guaifenesin; triamterene; silicate (overuse of antacids containing magnesium silicate); and sulfa drugs including sulfasalazine, sulfadiazine, acetylsulfamethoxazole, acetylsulfasoxazole, and acetylsulfaguanidine.
More on Renal Calculi |
Overview: Renal Calculi |
| Differential Diagnoses & Workup: Renal Calculi |
| Treatment & Medication: Renal Calculi |
| Follow-up: Renal Calculi |
| Multimedia: Renal Calculi |
| References |
| Next Page » |
References
Bove P, Kaplan D, Dalrymple N, et al. Reexamining the value of hematuria testing in patients with acute flank pain. J Urol. Sep 1999;162(3 Pt 1):685-7. [Medline].
Press SM, Smith AD. Incidence of negative hematuria in patients with acute urinary lithiasis presenting to the emergency room with flank pain. Urology. May 1995;45(5):753-7. [Medline].
Lindqvist K, Hellstrom M, Holmberg G, et al. Immediate versus deferred radiological investigation after acute renal colic: a prospective randomized study. Scand J Urol Nephrol. 2006;40(2):119-24. [Medline].
Sudah M, Vanninen R, Partanen K, et al. MR urography in evaluation of acute flank pain: T2-weighted sequences and gadolinium-enhanced three-dimensional FLASH compared with urography. Fast low-angle shot. AJR Am J Roentgenol. Jan 2001;176(1):105-12. [Medline].
Dellabella M, Milanese G, Muzzonigro G. Efficacy of tamsulosin in the medical management of juxtavesical ureteral stones. J Urol. Dec 2003;170(6 Pt 1):2202-5. [Medline].
Dellabella M, Milanese G, Muzzonigro G. Randomized trial of the efficacy of tamsulosin, nifedipine and phloroglucinol in medical expulsive therapy for distal ureteral calculi. J Urol. Jul 2005;174(1):167-72. [Medline].
Porpiglia F, Ghignone G, Fiori C, et al. Nifedipine versus tamsulosin for the management of lower ureteral stones. J Urol. Aug 2004;172(2):568-71. [Medline].
Singh A, Alter HJ, Littlepage A. A systematic review of medical therapy to facilitate passage of ureteral calculi. Ann Emerg Med. Nov 2007;50(5):552-63. [Medline].
Beach MA, Mauro LS. Pharmacologic expulsive treatment of ureteral calculi. Ann Pharmacother. Jul-Aug 2006;40(7-8):1361-8. [Medline].
St Lezin M, Hofmann R, Stoller ML. Pyonephrosis: diagnosis and treatment. Br J Urol. Oct 1992;70(4):360-3. [Medline].
Jeffrey RB, Laing FC, Wing VW. Sensitivity of sonography in pyonephrosis: a reevaluation. AJR Am J Roentgenol. Jan 1985;144(1):71-3. [Medline].
Schneider K, Helmig FJ, Eife R. Pyonephrosis in childhood--is ultrasound sufficient for diagnosis?. Pediatr Radiol. 1989;19(5):302-7. [Medline].
Finkielstein VA, Goldfarb DS. Strategies for preventing calcium oxalate stones. CMAJ. May 9 2006;174(10):1407-9. [Medline].
Borrero E, Queral LA. Symptomatic abdominal aortic aneurysm misdiagnosed as nephroureterolithiasis. Ann Vasc Surg. Apr 1988;2(2):145-9. [Medline].
Barrett BJ, Parfrey PS, McDonald JR, et al. Nonionic low-osmolality versus ionic high-osmolality contrast material for intravenous use in patients perceived to be at high risk: randomized trial. Radiology. Apr 1992;183(1):105-10. [Medline].
Boulay I, Holtz P, Foley WD, et al. Ureteral calculi: diagnostic efficacy of helical CT and implications for treatment of patients. AJR Am J Roentgenol. Jun 1999;172(6):1485-90. [Medline].
Catalano O, De Sena G, Nunziata A. The color Doppler US evaluation of the ureteral jet in patients with urinary colic. Radiol Med (Torino). Jun 1998;95(6):614-7. [Medline].
Chandhoke PS. Metabolic abnormalities and the medical management of calcium oxalate nephrolithiasis. Minerva Urol Nefrol. Mar 2005;57(1):9-16. [Medline].
Chen MY, Zagoria RJ. Can noncontrast helical computed tomography replace intravenous urography for evaluation of patients with acute urinary tract colic?. J Emerg Med. Mar-Apr 1999;17(2):299-303. [Medline].
Dretler SP. The physiologic approach to the medical management of stone disease. Urol Clin North Am. Nov 1998;25(4):613-23, ix. [Medline].
Dundee P, Bouchier-Hayes D, Haxhimolla H, et al. Renal tract calculi: comparison of stone size on plain radiography and noncontrast spiral CT scan. J Endourol. Dec 2006;20(12):1005-9. [Medline].
Erwin BC, Carroll BA, Sommer FG. Renal colic: the role of ultrasound in initial evaluation. Radiology. Jul 1984;152(1):147-50. [Medline].
Fultz PJ, Hampton WR, Totterman SM. Computed tomography of pyonephrosis. Abdom Imaging. 1993;18(1):82-7. [Medline].
Hill MC, Rich JI, Mardiat JG, Finder CA. Sonography vs. excretory urography in acute flank pain. AJR Am J Roentgenol. Jun 1985;144(6):1235-8. [Medline].
Joudi FN, Kuehn DM, Williams RD. Maximizing clinical information obtained by CT. Urol Clin North Am. Aug 2006;33(3):287-300. [Medline].
Labrecque M, Dostaler LP, Rousselle R, et al. Efficacy of nonsteroidal anti-inflammatory drugs in the treatment of acute renal colic. A meta-analysis. Arch Intern Med. Jun 27 1994;154(12):1381-7. [Medline].
Laing FC, Jeffrey RB Jr, Wing VW. Ultrasound versus excretory urography in evaluating acute flank pain. Radiology. Mar 1985;154(3):613-6. [Medline].
Larkin GL, Peacock WF 4th, Pearl SM, et al. Efficacy of ketorolac tromethamine versus meperidine in the ED treatment of acute renal colic. Am J Emerg Med. Jan 1999;17(1):6-10. [Medline].
Mariappan P, Loong CW. Midstream urine culture and sensitivity test is a poor predictor of infected urine proximal to the obstructing ureteral stone or infected stones: a prospective clinical study. J Urol. Jun 2004;171(6 Pt 1):2142-5. [Medline].
Miller OF, Rineer SK, Reichard SR, et al. Prospective comparison of unenhanced spiral computed tomography and intravenous urogram in the evaluation of acute flank pain. Urology. Dec 1998;52(6):982-7. [Medline].
Mutgi A, Williams JW, Nettleman M. Renal colic: utility of the plain abdominal roentgenogram. Arch Intern Med. Aug 1991;151(8):1589-92. [Medline].
Neville A, Hatem SF. Renal medullary carcinoma: unsuspected diagnosis at stone protocol CT. Emerg Radiol. Sep 2007;14(4):245-7. [Medline].
Pais VM Jr, Payton AL, LaGrange CA. Urolithiasis in pregnancy. Urol Clin North Am. Feb 2007;34(1):43-52. [Medline].
Pak CY, Resnick MI. Medical therapy and new approaches to management of urolithiasis. Urol Clin North Am. May 2000;27(2):243-53. [Medline].
Ramakumar S, Patterson DE, LeRoy AJ, et al. Prediction of stone composition from plain radiographs: a prospective study. J Endourol. Jul-Aug 1999;13(6):397-401. [Medline].
Ramakumar S, Segura JW. Renal calculi. Percutaneous management. Urol Clin North Am. Nov 2000;27(4):617-22. [Medline].
Russinko PJ, Agarwal S, Choi MJ, Kelty PJ. Obstructive nephropathy secondary to sulfasalazine calculi. Urology. Oct 2003;62(4):748. [Medline].
Sidhu R, Bhatt S, Dogra V. Renal Colic. Ultrasound Clinics. Jan 2008;3:159-170.
Sinclair D, Wilson S, Toi A, Greenspan L. The evaluation of suspected renal colic: ultrasound scan versus excretory urography. Ann Emerg Med. May 1989;18(5):556-9. [Medline].
Smith RC, Verga M, McCarthy S, Rosenfield AT. Diagnosis of acute flank pain: value of unenhanced helical CT. AJR Am J Roentgenol. Jan 1996;166(1):97-101. [Medline].
Springhart WP, Marguet CG, Sur RL, et al. Forced versus minimal intravenous hydration in the management of acute renal colic: a randomized trial. J Endourol. Oct 2006;20(10):713-6. [Medline].
Thomas A, Woodard C, Rovner ES, Wein AJ. Urologic complications of nonurologic medications. Urol Clin North Am. Feb 2003;30(1):123-31. [Medline].
Venkat A, Piontkowsky DM, Cooney RR, et al. Care of the HIV-positive patient in the emergency department in the era of highly active antiretroviral therapy. Ann Emerg Med. Sep 2008;52(3):274-85. [Medline].
Wen CC, Nakada SY. Treatment selection and outcomes: renal calculi. Urol Clin North Am. Aug 2007;34(3):409-19. [Medline].
Whelan C, Schwartz BF. Bilateral guaifenesin ureteral calculi. Urology. Jan 2004;63(1):175-6. [Medline].
Wu TT, Lee YH, Tzeng WS, et al. The role of C-reactive protein and erythrocyte sedimentation rate in the diagnosis of infected hydronephrosis and pyonephrosis. J Urol. Jul 1994;152(1):26-8. [Medline].
Further Reading
Keywords
renal calculi, kidney stones, kidney stone, renal stone, ureteral calculi, nephrolithiasis, ureterolithiasis, kidney calculi, acute nephrolithiasis
Overview: Renal Calculi