Urolithiasis: Difference between revisions

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==Background==
==Background==
*Types
[[File:Urinary system.png|thumb|'''(1) Human urinary system:''' (2) kidney; (3) renal pelvis; (4) ureter; (5) urinary bladder (6) urethra. <Br>'''Additional structures:''' (7) adrenal gland; (8) renal artery and vein; (9) inferior vena cava; (10) abdominal aorta; (11) common iliac artery and vein; (12) liver; (13) large intestine; (14) pelvis.]]
**Calcium (75%)
*Urolithiasis comprises 3 similar clinical entities:
***Hyperparathyroidism, hypercalcemia of malignancy, sarcoidosis, increased absorption, thiazides, IBD
**Nephrolithiasis
**Struvite (magnesium-ammonium-phosphate) (15%)  
**Ureterolithiasis
***Proteus, klebsiella, pseudomonas, staph
**Cystolithiasis
**Uric Acid (10%)
***25% of pts w/ gout develop kidney stones


If unrelieved, irreversible renal damage occurs within 3 weeks with complete obstruction. During acute obstruction, most patients have no rise in serum creatinine because the unobstructed kidney functions at up to 185% of its baseline capacity. A rise in serum creatinine in acute obstruction suggests a solitary kidney or preexisting renal disease such that the unobstructed kidney is unable to compensate completely. Fortunately, most patients have incomplete ureteral obstruction, and many patients can be safely observed over weeks. Irreversible renal damage from an obstructive kidney stone is rare if obstruction has not been present for >1 month.
*The most common cause is infection of residual bladder urine with urea-splitting organisms ([[Proteus]], [[Pseudomonas]], [[Klebsiella]], [[Staphylococcus]],[[Mycoplasma]], [[Providentia stuartii]], [[Serratia]], and [[Morganella morganii]])


==Clinical Features==
*Promoters of stone formation <ref> Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Recent advances on the mechanisms of kidney stone formation (Review). Int J Mol Med. 2021 Aug;48(2):149. doi: 10.3892/ijmm.2021.4982. Epub 2021 Jun 16. PMID: 34132361; PMCID: PMC8208620.</ref>
acute onset of a crampy intermittent pain that originates in the flank and radiates toward the groin. As pain originates from a hollow viscus (ureter), the pain is visceral in nature without associated peritoneal irritation. Patients writhe in pain, unable to find a position of comfort. However, patients with renal colic may demonstrate rebound tenderness (29%), guarding (61%), and rigidity (8%).13 Pain is commonly accompanied by nausea and vomiting (50%). The adrenergic response to pain can result in tachycardia, hypertension, and diaphoresis. Hematuria is present in approximately 85% of patients with renal colic, whereas only 30% have gross hematuria.
**High serum calcium
**High uric acid and phosphate
**Urine pH abnormalities, either high or low


The location of the pain correlates somewhat with the location of the stone. Stones in the upper ureter refer pain to the flank, whereas those in the mid-ureter radiate to the lower anterior quadrant of the abdomen. A distal ureter stone, which is where 75% of stones are diagnosed, refers pain to the groin. Stones positioned at the UVJ can mimic a urinary tract infection (UTI) by causing frequency, urgency, and dysuria in 3% to 24% of patients.13
*Inhibitors of stone formation <ref> Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Recent advances on the mechanisms of kidney stone formation (Review). Int J Mol Med. 2021 Aug;48(2):149. doi: 10.3892/ijmm.2021.4982. Epub 2021 Jun 16. PMID: 34132361; PMCID: PMC8208620.</ref>
**Citrate
**Magnesium
**Various macromolecules


===Renal damage===
*Irreversible renal damage can occur within 3 weeks in patients with a complete obstruction
*Most have no rise in creatinine because unobstructed kidney functions at up to 185% of its baseline capacity


During the interview, elucidate three separate items of history. Ask about risk factors for stone development (Table 97-1), risk factors for a poor stone-related outcome, and risk factors for important mimickers. The risk factors for a poor outcome with stones include three categories: renal function is at risk (diabetes, hypertension, preexisting renal insufficiency, single kidney or transplant), history of difficulty with stones (extractions, stents, ureterostomy tubes), and infection (fever, systemic illness, and UTI symptoms; Table 97-2). Two mimickers that are very important to exclude are abdominal aortic aneurysm (AAA) and renal artery infarction. Nephrolithiasis is the most common misdiagnosis given to patients with a rupturing or expanding AAA. Recall that stones don't usually present in men older than age 60 and do not cause hypotension, even transiently. Renal artery thrombosis can mimic stone symptoms due to swelling of the infarcted kidney and can also be associated with hematuria. However, early in the course, CT will not necessarily show inflammation around the kidney, and, because no contrast is used, the function of the kidney is not assessed.
===Epidemiology===
*1-15% lifetime incidence
*More common in males
*50% recurrence rate within 5-10 years
*More common in hot dry climates


===Infection===
*8-15% of kidney stones have urinary co-infection<ref name="a">Abrahamian FM, et al. Association of pyuria and clinical characteristics with presence of urinary tract infection among patients with acute nephrolithiasis. Annals of EM. 2013; 62(5):526-533.</ref>
**Fever, pyuria >10 WBC/hpf, and peripheral WBC >11.3 (any one) best predictors of concomitant UTI<ref name="a"/>


Important Historical Features for Poor Outcome with Stone
===Stone Expulsion Rate===
Renal function at risk 
{| {{table}}
Diabetes
| align="center" style="background:#f0f0f0;"|'''Stone Size'''
Hypertension
| align="center" style="background:#f0f0f0;"|'''Passage Rate<ref>Coll DM et al. Relationship of spontaneous passage of ureteral calculi to stone size and location as revealed by unenhanced helical CT. AJR Am J Roentgenol 2002 Jan; 178:101-3.</ref>'''
Renal insufficiency
|-
Single kidney
| 1-4 mm||78%
Horseshoe kidney
|-
Transplanted kidney
| 5 -7 mm||60%
History of difficulty with stones 
|-
Extractions
| >8mm||39%
Stents
|}
Ureterostomy tubes
Lithotripsy
Symptoms of infection 
Fever
Hypotension
Systemic illness
Urinary tract infection
Diagnosis
The laboratory evaluation centers on evaluating for infection, kidney dysfunction, and possibility of pregnancy. Test all females of childbearing potential for pregnancy when considering renal colic.


Urinalysis is needed to rule out infection. If infection is found, obtain urine culture and sensitivities, as requirement for antibiotic therapy may be prolonged,14 and sensitivities help guide therapy if the empiric antibiotic fails.
===Types===
<ref> Teichman JM. Clinical practice. Acute renal colic from ureteral calculus. N Engl J Med. 2004 Feb 12;350(7):684-93. doi: 10.1056/NEJMcp030813. PMID: 14960744.</ref>
<ref> Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Recent advances on the mechanisms of kidney stone formation (Review). Int J Mol Med. 2021 Aug;48(2):149. doi: 10.3892/ijmm.2021.4982. Epub 2021 Jun 16. PMID: 34132361; PMCID: PMC8208620.</ref>


Although 10% to 15% of patients with nephrolithiasis will have no hematuria, approximately 24% of patients with flank pain and hematuria have no radiographic evidence of ureterolithiasis.15 Therefore, although hematuria may contribute to diagnostic decision making, it should not be used alone to exclude or confirm the diagnosis of ureterolithiasis.15
*Calcium (~80%): Mostly calcium oxylate >> calcium phosphate
 
**[[Hyperparathyroidism]], [[hypercalcemia of malignancy]], [[sarcoidosis]], increased absorption, loop diuretics, [[IBD]]
Check renal function with both blood urea nitrogen and creatinine level, as the overwhelming majority of stone formers have reduced creatinine clearance.16 These studies allow for identification of renal failure due to obstruction and establish a baseline for future evaluations. Unless febrile or systemically ill, a white blood cell count does not aid in the evaluation
*The remainder
 
**Struvite (magnesium ammonium phosphate) 
 
***Associated with infection with urease-producing bacteria such as [[Proteus]], [[klebsiella]], [[pseudomonas]], [[staph]],[[Providentia stuartii]], [[Serratia]], and [[Morganella morganii]]
==Imaging==
**Uric Acid 
It is unclear whether all patients with first time stones require ED imaging for suspected renal colic. For young, healthy patients in whom the diagnosis is clinically clear, one study suggested imaging could be conducted later on an outpatient basis.18 However, another study showed that clinicians are often wrong based on clinical suspicion alone.19 In patients for whom the initial clinical suspicion of stone was 0% to 50%, a stone was present in 29%. In patients for whom the physician had a high pretest clinical suspicion (90% to 100%) of a stone, a stone was present in only 80%. In this same study, CT scanning revealed an alternative diagnosis in 33% of the patients. Thus, these authors strongly advise imaging for patients presenting with a first time stone, with a CT scan to both confirm the suspicion and identify alternative diagnoses.19 As for patients with repeat stones, the issue of imaging hinges on several items. Did the patient have a complication with the previous stone that imaging would aid in preventing? Is the diagnosis in question (i.e., drug seeker, >50)? And finally, for type of evaluation, what is the patient's previous radiation load?
***25% of patients with [[gout]] develop kidney stones
 
**Cystine
CT
**Multiple types of crystals
In combination, unilateral ureteral dilatation and perinephric stranding have a PPV of 96% for stone disease.21 If both are absent, the NPV is 93% to 97%
 
US
Although useful in the detection of larger stones (Figure 97-3), it may miss smaller (<5 mm in diameter) ureteral stones.27 US is helpful in diagnosing stones in the proximal and distal ureters but is insensitive for mid-ureteral stones. Overall, US has only modest sensitivity and specificity for detecting renal stones (Table 97-3) but is 98% sensitive for detecting hydronephrosis (see Figure 91-2B). However, of hydronephrosis diagnosed by US, up to 22% of studies do not represent obstruction, but rather, normal anatomic variation, full bladder, and renal cysts.24 Rapid bolus infusion of crystalloid can result in a false positive finding of hydroureter.


==Risk Factors for Complications==
*Renal function at risk 
**[[DM]]
**[[Hypertension ]]
**[[HIV]]
**Renal insufficiency
**Single kidney
**Horseshoe kidney
**Transplanted kidney
*History of difficulty with stones 
**Extractions
**Stents
**Ureterostomy tubes
**Lithotripsy
*Symptoms of infection 
**[[Fever]]
**[[Hypotension]]
**Systemic illness
**[[UTI]]
*Immunosuppression
**[[DM]]
**[[AIDS]]
**[[Chemotherapy]]


==Clinical Features==
[[File:Pos-renal.png|thumb|Diagram showing the classic location of renal colic.]]
*Pain
**Acute onset, crampy, intermittent, unable to find position of comfort
**Location of pain depends on location of stone:
***Upper ureter: [[flank pain]]
***Mid ureter: lower anterior quadrant of [[abdominal pain|abdomen]]
***Distal ureter: groin pain
***UVJ: Can mimic a [[UTI]] (frequency, urgency, [[dysuria]])
*[[Nausea/vomiting]] (50%)
*[[Hematuria]] (85%)


==Differential Diagnosis==
''Nephrolithiasis is most common misdiagnosis given to patients with rupturing [[AAA]]''
{{Flank pain DDX}}


{{Lower back pain DDX}}


==Evaluation==
===Labs===
*[[Urinalysis]]: [[hematuria]]
**Hematuria cannot be used to rule-out or rule-in stone (sensitivity 71-95%; specificity 18-49%)<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
**The absence of pyuria cannot exclude a complicating UTI (sensitivity 86%; specificity 79%)<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
*Urine culture :
**Consider for all patients<ref name="a"/> '''OR''' those at higher risk (female, pyuria, or [[cystitis]] symptoms)<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
*Urine pregnancy
*Chemistry
**BUN/Cr to evaluate renal function
*CBC: If concern for infection (>15k concerning)


===Imaging===
*Consider tailoring your choice of imaging based upon the patient's age, clinical likelihood of stones, risk factors, and prior history of stones<ref>Imaging in suspected renal colic: systematic review of the literature and multispecialty consensus Moore CL, Carpenter CR, Heilbrun ME, et al. Ann Emerg Med. 2019;74(3):391-399.</ref>
**In young patients, even with no prior history of kidney stones, reasonable approaches may be bedside ultrasound or no imaging
**In middle aged patients with prior history of stones, it may be reasonable to perform a bedside ultrasound although no imaging can be appropriate as well
**In middle aged patients with no prior history of stones, CT imaging is reasonable
**In elderly patients, even with prior history of stones, CT is recommended in order to avoid missing alternative etiologies such as dissection, AAA, or diverticulitis.
[[File:3mm renal stone2.png|thumb|Axial CT scan of abdomen without contrast, showing a 3-mm stone (marked by an arrow) in the proximal ureter.]]
*Bedside [[Renal ultrasound]]
[[File:Ultrasonography_of_renal_stone_located_at_the_pyeloureteral_junction.jpg|thumb|[[Renal ultrasound]] of a stone located at the pyeloureteral junction with accompanying hydronephrosis.]]
*Consider non-contrast CT abdomen and pelvis (KUB protocol) for:
**1st time stone
**Older patients with other possible diagnosis
**Avoid CT in young (<50 years old), health patients with known history of nephrolithiasis with presentation consistent with renal colic<ref>Part of [[Choosing wisely ACEP]]</ref>
*Consider formal [[ultrasound]] for:
**Pregnant pt
**Repeat stone (to avoid CT)
*In comparison of diagnosis by CT vs. U/S (by EP) vs. U/S (by radiologist):<ref>Smith-Bindman R, Aubin C, Bailitz J, et al. Ultrasonography versus computed tomography for suspected nephrolithiasis. NEJM. 2014; 371(12):1100–1110.</ref>
**No difference in rate of missed high-risk diagnoses that resulted in complications (pyelo/sepsis/diverticular abscess)
**No difference in rate of serious adverse events, pain scores, return emergency department visits, or hospitalizations


===Imaging Findings===
*CT Imaging
**Hydronephrosis
**Hydroureter
**Hydrocalyx
**Note: Hydronephrosis, hydroureter, hydrocalyx alone indicate obstructive uropathy, stone must be seen or collected (if passed) in order to diagnose nephrolithiasis as the etiology.
**Perinephric Stranding
**'''Location Landmarks'''
***Renal: Does not cause pain, and usually considered an incidental finding
***UPJ: Ureteropelvic Junction
***UVJ Ureterovesicular Junction


=== Pass Rates ===
==Management==
Based on stone size alone, 98% of stones <5 mm will pass within 4 weeks without intervention. Sixty percent of stones 5 to 7 mm and 39% of stones >7 mm will pass within 4 weeks. Stone size on plain radiographs is magnified by up to 20%, and a measured stone on CT is 88% of actual stone size
===Pain===
*[[Ketorolac]] 15mg IV  or  [[Ibuprofen]] 600mg PO Q6hrs PRN if the patient can tolerate oral medications<ref>Pathan, SA et al. Delivering safe and effective analgesia for management of renal colic in the emergency department: a double-blind, multi-group, randomised controlled trial. Lancet. 2016 May 14;387(10032): 1999-2007</ref>
**Avoid high dose NSAIDS in patients with renal failure or insufficiency.
**Ketorolac 15 mg has similar effects to the traditional 30 mg dosage. <ref> Motov S, et al. Comparison of Intravenous Ketorolac at Three Single-Dose Regimens for Treating Acute Pain in the Emergency Department: A Randomized Controlled Trial. Ann Emerg Med. 2017 Aug;70(2):177-184. doi: 10.1016 </ref>
*[[Morphine]] or  other [[Opioids]]
**Severe pain not controlled with NSAIDS
**Contraindications to NSAIDS
**eGFR <30 mL/min


'''Size'''
===Antiemetic===
*4mm ~75%
*[[Metoclopramide]]
*4-6mm ~50%
*[[Ondansetron]]
*&gt;6mm ~10%


'''Location in Ureter'''
===Expulsion Therapy===
#Distal ~70%  
*Consider [[Tamsulosin]] 0.4mg PO QHS (discontinued after successful expulsion; average 1-2 weeks)
#Middle ~50%
**The American Urological Association (AUA) advocates the use of medical expulsive therapy in the form of alpha-blockers (tamsulosin) for uncomplicated distal ureteric stones ≤10 mm (Strong recommendation). The EAU suggests that alpha-blockers be used only in distal ureteric stones >5 mm because a large randomized controlled trial demonstrated no benefit in using alpha-blockers for distal ureteric stones of <5 mm.<ref>Hughes T, Ho HC, Pietropaolo A, Somani BK. Guideline of guidelines for kidney and bladder stones. Turk J Urol. 2020 Nov;46(Supp. 1):S104-S112. doi: 10.5152/tud.2020.20315. Epub 2020 Oct 9. PMID: 33052834; PMCID: PMC7731951.</ref>
#Proximal ~20%
**See [[EBQ:Alpha-blockers for ureteral stone expulsion]] discussion of evidence
**76% vs 48% passage rates in tamsulosin vs no treatment, respectively<ref>Hollingsworth JM et al. α-blockers for treatment of ureteric stones: systematic review and meta-analysis. BMJ 2016;355:i6112.</ref>
***Only patients with stones ≥ 5 mm benefited
***Review of 55 RTCs, with NNT of 4
**Tamsulosin number needed to harm (orthostatic hypotension)= 19 (give at night, to reduce side effect rate)<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
*Use of IV fluids to "flush out" stone has NOT been shown to improve clinical outcomes<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>


== DDx  ==
==Infected Urolithiasis==
#[[Cholelithiasis]] (5%)
''Inpatient observation is often the safest disposition for patients with infected stones due to the risk of progressing to [[sepsis]]. All antibiotics should take into account patient's previous sensitivities and local antibiograms.''
#Appy (4%)
{{Pyelonephritis antibiotics}}
#Pyelonephitis (3%)
#Ovarian cyst (2%)
#Renal mass (1.4%)
#[[AAA]] w/or w/o rupture (1.4%)


Differential Diagnoses for Ureterolithiasis
===Surgical Removal===
Considered for ureterolithiasis with:
Vascular Aortic dissection
*Persistent obstruction
Abdominal aortic aneurysm
*Failure of stone progression
Renal artery embolism
*Increasing or unremitting colic
Renal vein thrombosis
*Staghorn calculi
Mesenteric ischemia
Renal Pyelonephritis
Papillary necrosis
Renal cell carcinoma
Renal infarct
Renal hemorrhage
Ureter Blood clot
Stricture
Tumor (primary or metastatic)
Bladder Tumor
Varicose vein
Cystitis
GI Biliary colic
Pancreatitis
Perforated peptic ulcer disease
Appendicitis
Inguinal hernia
Diverticulitis
Cancer
Bowel obstruction
Gynecologic Ectopic pregnancy
Pelvic inflammatory disease/tubo-ovarian abscess
Ovarian cyst
Ovarian torsion
Endometriosis
GU Testicular torsion
Epididymitis
Other Drug-seeking behavior
Shingles
Retroperitoneal hematoma/abscess/tumor
 
 
 
== Treatment  ==
#ED
##Toradol 30mg IV/IM
##Morphine 3-5mg IV
#Outpt
##NSAIDS PO
##Vicodin PO
##Smooth muscle relaxant (alpha-adrenergic blocker)
###Tamsulosin (Flomax) 0.4mg PO QHS x 21 days, OR
###Terazosin (Hytrin) 1mg PO QHS x 21 days
 
 
primary choice of analgesics in the treatment of stone disease, as they have a direct action on the ureter by inhibiting prostaglandin synthesis.31,32 IV administration achieves more rapid relief than IM or PO dosing33 (for example, ketorolac, 30 milligrams IV). NSAIDs should be used with caution in patients with GI bleeding risks and renal impairment. Narcotics (for example, hydromorphone, 0.5 to 2.0 milligrams IV) are good analgesics but do not affect the cause of pain. As both the pain of the stone and narcotics can cause nausea and vomiting, address these symptoms as well.
 
Metoclopramide is the only antiemetic that has been specifically studied in the treatment of renal colic. In two double-blinded studies, metoclopramide provided pain relief equivalent to narcotic analgesics in addition to relieving nausea. Metoclopramide works by blocking dopaminergic receptors in the central nervous system, but is less sedating than other centrally acting dopamine antagonists.34
 
For patients in whom admission is anticipated, recommended IV antibiotics for the treatment of stones associated with infection include gentamicin or tobramycin, 3.0 milligrams/kg/day divided every 8 hours, plus ampicillin, 1 to 2 grams every 4 hours; piperacillin-tazobactam, 3.375 grams IV every 6 hours; cefepime, 2 grams IV every 8 hours; ticarcillin-clavulanic acid, 3.1 grams every 6 hours; or ciprofloxacin, 400 milligrams every 12 hours, if local sensitivities do not predict treatment failure. Patients who have a ureteral stone with an associated UTI but no evidence of significant obstruction, fever, or systemic illness can be treated as outpatients. Provide urologic follow-up in 48 to 72 hours, as well as detailed discharge instructions to return to the ED for fever, nausea, and systemic illness. The choice of antibiotic should cover gram-negative rods and be appropriate for antibiotic sensitivity at your institution. Resistance rates of >10% to 20% should preclude use of that antibiotic. Choices include: ciprofloxacin, 500 milligrams PO twice a day for 10 to 14 days; levofloxacin, 500 milligrams PO once a day for 10 to 14 days; cefpodoxime, 200 milligrams PO twice a day for 10 to 14 days; or others predicted to be successful based on local sensitivities.
 
-Blockers are associated with increased rate of expulsion, decreased time to expulsion, and decreased pain, with a number needed to treat of 3.3 and a 2- to 6-day improvement in time to expulsion.35 Approximately 4% of patients have associated adverse effects. The benefit is limited to stones in the distal third of the ureter, because it is thought that there are an increased number and density of -receptors in the distal ureter. The most commonly used agent is tamsulosin (0.4 milligrams PO daily for up to 4 weeks), but terazosin (5 to 10 milligrams daily) and doxazosin (4 milligrams daily) are also as effective
 
=== Surgical Treatment===
Persistent obstruction, failure of stone progression, or increasing or unremitting colic
Antibiotic penetration into staghorn calculi is poor, and the potential for urosepsis exists as long as the stones remain. Consequently, surgical treatment is recommended for staghorn calculi.
 
Shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy


==Disposition==
==Disposition==
Admit for:
===Admission===
#Intractable pain (on orals)
'''Recommended for any of the following:'''
#Solitary or transplanted kidney
*Intractable pain or vomiting<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
#Presence of urinary tract infection (UTI), fever, sepsis, or pyonephrosis
*Proximal [[urinary tract infection]],<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref> as evidence by:
 
**[[Urosepsis]]:
Most patients with stones are discharged with urologic or primary care follow-up, at which time preventive therapy may be considered based on stone type.36 Because of lower rates of spontaneous passage, patients with large (>5 mm), irregular, or proximal stones should be considered for admission (Table 97-5). In severe concurrent underlying disease (e.g., angina or chronic obstructive pulmonary disease) or in the fragile elderly who may be unable to tolerate the stress of renal colic, a lower admission threshold is indicated. There is also a subset of patients who may require emergent decompression. Examples include those with a solitary kidney and complete obstruction, ureterolithiasis with hydronephrosis and fever, and urosepsis with obstruction. In addition, disposition should be discussed with a urologist and follow-up within 1 week obtained if there is (1) renal insufficiency, (2) severe underlying disease, (3) an IV urogram showing extravasation or complete obstruction, (4) multiple ED visits, (5) a stone >6 mm, (6) sloughed renal papillae, or (7) associated UTI without sepsis.
***[[Fever]]
 
***Hypotension
Table 97-5 Indications for Admission
***Ill appearance, '''OR'''
 
***Markedly elevated WBC
***Elevated serum lactate
*Single or transplanted kidney with obstruction<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
Absolute Indications for Admission Relative Indications for Admission
*Acute renal failure<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
Intractable pain or vomiting
*[[Hypercalcemic Crisis]]
Fever
Urosepsis
Solitary kidney or transplanted kidney without obstruction
Single or transplanted kidney with obstruction
Obstructing stone with signs of urinary infection
Acute renal failure
Hypercalcemic crisis
Urinary extravasation
Severe medical comorbidities
Significant medical comorbidities
  Stone unlikely to pass—large stone in proximal ureter
 
 
Discharge is appropriate in those with smaller stones; in the absence of infection; and when pain is controlled by oral analgesics. Give patients a urinary strainer with instructions to save any stones they pass for pathologic evaluation. Average time for stone passage varies according to size and location, but may range up to 7 to 20 days for stones 5 to 6 mm in diameter. Patients should be counseled to return promptly for fever, vomiting, or uncontrolled pain. A prescription for an oral opiate and NSAIDs should be provided, as well as for medical expulsive therapy if used. Follow-up with a urologist within 7 days should be recommended.
 
If the stone passes in the ED, no further treatment is required. Elective urologic consultation is recommended so that the etiology of the stone is evaluated and a prophylactic strategy can be arranged. Patients with hematuria, negative imaging studies, and no other source require outpatient urologic follow-up to determine the cause of hematuria.
 
 
==Prognosis==
=== Recurrence Rates  ===
 
1 yr ~33%
 
5yr ~50%
 
#Increasing H2O intake decreases rate
#Protease inhibitors and diuretics increases rate
 


Patients who have a known stone who return for continued pain should be evaluated for worsening renal function (blood urea nitrogen/creatinine), evidence of obstruction (US to limit radiation exposure), evidence of infection (repeat urinalysis and review for systemic symptoms), movement of stone (repeat KUB), and clear evidence that a stone was the original cause of the pain. If all of these issues do not suggest a urologic emergency, the patient's pain management regimen should be altered. Consider metoclopramide, NSAIDs, opioids, -blockers, and, possibly, steroids.
'''Also consider admission for patients with:'''
*Solitary kidney or transplanted kidney without obstruction
*Urinary extravasation
*Significant medical comorbidities


===Consultation===
*Renal insufficiency
*Severe underlying disease
*Stone >10 mm<ref name="Wang RC">Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454</ref>
*Sloughed renal papillae
*Unclear/distal [[UTI]]
*Ruptured renal capsule causing urinoma
*pregnancy
*children


===Discharge===
*Small stone in patient with adequate analgesia and able to arrange urology follow up within 7d


==See Also==
==See Also==
[[EBQ Medical Treatment for Nephrolithiasis]]
*[[Flank pain]]
*[[EBQ:Hematuria in Renal Colic]]


== Source  ==
==References==
Tintinalli
<references/>


[[Category:Nephro]]
[[Category:Renal]]

Latest revision as of 03:48, 22 May 2024

Background

(1) Human urinary system: (2) kidney; (3) renal pelvis; (4) ureter; (5) urinary bladder (6) urethra.
Additional structures: (7) adrenal gland; (8) renal artery and vein; (9) inferior vena cava; (10) abdominal aorta; (11) common iliac artery and vein; (12) liver; (13) large intestine; (14) pelvis.
  • Urolithiasis comprises 3 similar clinical entities:
    • Nephrolithiasis
    • Ureterolithiasis
    • Cystolithiasis
  • Promoters of stone formation [1]
    • High serum calcium
    • High uric acid and phosphate
    • Urine pH abnormalities, either high or low
  • Inhibitors of stone formation [2]
    • Citrate
    • Magnesium
    • Various macromolecules

Renal damage

  • Irreversible renal damage can occur within 3 weeks in patients with a complete obstruction
  • Most have no rise in creatinine because unobstructed kidney functions at up to 185% of its baseline capacity

Epidemiology

  • 1-15% lifetime incidence
  • More common in males
  • 50% recurrence rate within 5-10 years
  • More common in hot dry climates

Infection

  • 8-15% of kidney stones have urinary co-infection[3]
    • Fever, pyuria >10 WBC/hpf, and peripheral WBC >11.3 (any one) best predictors of concomitant UTI[3]

Stone Expulsion Rate

Stone Size Passage Rate[4]
1-4 mm 78%
5 -7 mm 60%
>8mm 39%

Types

[5] [6]

Risk Factors for Complications

  • Renal function at risk
    • DM
    • Hypertension
    • HIV
    • Renal insufficiency
    • Single kidney
    • Horseshoe kidney
    • Transplanted kidney
  • History of difficulty with stones
    • Extractions
    • Stents
    • Ureterostomy tubes
    • Lithotripsy
  • Symptoms of infection
  • Immunosuppression

Clinical Features

Diagram showing the classic location of renal colic.
  • Pain
    • Acute onset, crampy, intermittent, unable to find position of comfort
    • Location of pain depends on location of stone:
      • Upper ureter: flank pain
      • Mid ureter: lower anterior quadrant of abdomen
      • Distal ureter: groin pain
      • UVJ: Can mimic a UTI (frequency, urgency, dysuria)
  • Nausea/vomiting (50%)
  • Hematuria (85%)

Differential Diagnosis

Nephrolithiasis is most common misdiagnosis given to patients with rupturing AAA

Flank Pain

Lower Back Pain

Evaluation

Labs

  • Urinalysis: hematuria
    • Hematuria cannot be used to rule-out or rule-in stone (sensitivity 71-95%; specificity 18-49%)[7]
    • The absence of pyuria cannot exclude a complicating UTI (sensitivity 86%; specificity 79%)[7]
  • Urine culture :
    • Consider for all patients[3] OR those at higher risk (female, pyuria, or cystitis symptoms)[7]
  • Urine pregnancy
  • Chemistry
    • BUN/Cr to evaluate renal function
  • CBC: If concern for infection (>15k concerning)

Imaging

  • Consider tailoring your choice of imaging based upon the patient's age, clinical likelihood of stones, risk factors, and prior history of stones[8]
    • In young patients, even with no prior history of kidney stones, reasonable approaches may be bedside ultrasound or no imaging
    • In middle aged patients with prior history of stones, it may be reasonable to perform a bedside ultrasound although no imaging can be appropriate as well
    • In middle aged patients with no prior history of stones, CT imaging is reasonable
    • In elderly patients, even with prior history of stones, CT is recommended in order to avoid missing alternative etiologies such as dissection, AAA, or diverticulitis.
Axial CT scan of abdomen without contrast, showing a 3-mm stone (marked by an arrow) in the proximal ureter.
Renal ultrasound of a stone located at the pyeloureteral junction with accompanying hydronephrosis.
  • Consider non-contrast CT abdomen and pelvis (KUB protocol) for:
    • 1st time stone
    • Older patients with other possible diagnosis
    • Avoid CT in young (<50 years old), health patients with known history of nephrolithiasis with presentation consistent with renal colic[9]
  • Consider formal ultrasound for:
    • Pregnant pt
    • Repeat stone (to avoid CT)
  • In comparison of diagnosis by CT vs. U/S (by EP) vs. U/S (by radiologist):[10]
    • No difference in rate of missed high-risk diagnoses that resulted in complications (pyelo/sepsis/diverticular abscess)
    • No difference in rate of serious adverse events, pain scores, return emergency department visits, or hospitalizations

Imaging Findings

  • CT Imaging
    • Hydronephrosis
    • Hydroureter
    • Hydrocalyx
    • Note: Hydronephrosis, hydroureter, hydrocalyx alone indicate obstructive uropathy, stone must be seen or collected (if passed) in order to diagnose nephrolithiasis as the etiology.
    • Perinephric Stranding
    • Location Landmarks
      • Renal: Does not cause pain, and usually considered an incidental finding
      • UPJ: Ureteropelvic Junction
      • UVJ Ureterovesicular Junction

Management

Pain

  • Ketorolac 15mg IV or Ibuprofen 600mg PO Q6hrs PRN if the patient can tolerate oral medications[11]
    • Avoid high dose NSAIDS in patients with renal failure or insufficiency.
    • Ketorolac 15 mg has similar effects to the traditional 30 mg dosage. [12]
  • Morphine or other Opioids
    • Severe pain not controlled with NSAIDS
    • Contraindications to NSAIDS
    • eGFR <30 mL/min

Antiemetic

Expulsion Therapy

  • Consider Tamsulosin 0.4mg PO QHS (discontinued after successful expulsion; average 1-2 weeks)
    • The American Urological Association (AUA) advocates the use of medical expulsive therapy in the form of alpha-blockers (tamsulosin) for uncomplicated distal ureteric stones ≤10 mm (Strong recommendation). The EAU suggests that alpha-blockers be used only in distal ureteric stones >5 mm because a large randomized controlled trial demonstrated no benefit in using alpha-blockers for distal ureteric stones of <5 mm.[13]
    • See EBQ:Alpha-blockers for ureteral stone expulsion discussion of evidence
    • 76% vs 48% passage rates in tamsulosin vs no treatment, respectively[14]
      • Only patients with stones ≥ 5 mm benefited
      • Review of 55 RTCs, with NNT of 4
    • Tamsulosin number needed to harm (orthostatic hypotension)= 19 (give at night, to reduce side effect rate)[7]
  • Use of IV fluids to "flush out" stone has NOT been shown to improve clinical outcomes[7]

Infected Urolithiasis

Inpatient observation is often the safest disposition for patients with infected stones due to the risk of progressing to sepsis. All antibiotics should take into account patient's previous sensitivities and local antibiograms. Treatment is targeted at E. coli, Enterococcus, Klebsiella, Proteus mirabilis, S. saprophyticus.

Outpatient

Consider one dose of Ceftriaxone 1g IV or Gentamycin 7mg/kg IV if the regional susceptibility of TMP/SMX or Fluoroquinolones is <80%

Adult Inpatient Options

Pediatric Inpatient Options

Surgical Removal

Considered for ureterolithiasis with:

  • Persistent obstruction
  • Failure of stone progression
  • Increasing or unremitting colic
  • Staghorn calculi

Disposition

Admission

Recommended for any of the following:

Also consider admission for patients with:

  • Solitary kidney or transplanted kidney without obstruction
  • Urinary extravasation
  • Significant medical comorbidities

Consultation

  • Renal insufficiency
  • Severe underlying disease
  • Stone >10 mm[7]
  • Sloughed renal papillae
  • Unclear/distal UTI
  • Ruptured renal capsule causing urinoma
  • pregnancy
  • children

Discharge

  • Small stone in patient with adequate analgesia and able to arrange urology follow up within 7d

See Also

References

  1. ↑ Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Recent advances on the mechanisms of kidney stone formation (Review). Int J Mol Med. 2021 Aug;48(2):149. doi: 10.3892/ijmm.2021.4982. Epub 2021 Jun 16. PMID: 34132361; PMCID: PMC8208620.
  2. ↑ Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Recent advances on the mechanisms of kidney stone formation (Review). Int J Mol Med. 2021 Aug;48(2):149. doi: 10.3892/ijmm.2021.4982. Epub 2021 Jun 16. PMID: 34132361; PMCID: PMC8208620.
  3. ↑ 3.0 3.1 3.2 Abrahamian FM, et al. Association of pyuria and clinical characteristics with presence of urinary tract infection among patients with acute nephrolithiasis. Annals of EM. 2013; 62(5):526-533.
  4. ↑ Coll DM et al. Relationship of spontaneous passage of ureteral calculi to stone size and location as revealed by unenhanced helical CT. AJR Am J Roentgenol 2002 Jan; 178:101-3.
  5. ↑ Teichman JM. Clinical practice. Acute renal colic from ureteral calculus. N Engl J Med. 2004 Feb 12;350(7):684-93. doi: 10.1056/NEJMcp030813. PMID: 14960744.
  6. ↑ Wang Z, Zhang Y, Zhang J, Deng Q, Liang H. Recent advances on the mechanisms of kidney stone formation (Review). Int J Mol Med. 2021 Aug;48(2):149. doi: 10.3892/ijmm.2021.4982. Epub 2021 Jun 16. PMID: 34132361; PMCID: PMC8208620.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 Wang RC. Managing Urolithiasis. Annals of EM. April 2016. 67(4):449-454
  8. ↑ Imaging in suspected renal colic: systematic review of the literature and multispecialty consensus Moore CL, Carpenter CR, Heilbrun ME, et al. Ann Emerg Med. 2019;74(3):391-399.
  9. ↑ Part of Choosing wisely ACEP
  10. ↑ Smith-Bindman R, Aubin C, Bailitz J, et al. Ultrasonography versus computed tomography for suspected nephrolithiasis. NEJM. 2014; 371(12):1100–1110.
  11. ↑ Pathan, SA et al. Delivering safe and effective analgesia for management of renal colic in the emergency department: a double-blind, multi-group, randomised controlled trial. Lancet. 2016 May 14;387(10032): 1999-2007
  12. ↑ Motov S, et al. Comparison of Intravenous Ketorolac at Three Single-Dose Regimens for Treating Acute Pain in the Emergency Department: A Randomized Controlled Trial. Ann Emerg Med. 2017 Aug;70(2):177-184. doi: 10.1016
  13. ↑ Hughes T, Ho HC, Pietropaolo A, Somani BK. Guideline of guidelines for kidney and bladder stones. Turk J Urol. 2020 Nov;46(Supp. 1):S104-S112. doi: 10.5152/tud.2020.20315. Epub 2020 Oct 9. PMID: 33052834; PMCID: PMC7731951.
  14. ↑ Hollingsworth JM et al. α-blockers for treatment of ureteric stones: systematic review and meta-analysis. BMJ 2016;355:i6112.
  15. ↑ Gupta K, Hooton TM, Naber KG, et al. International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women. Clinical Infectious Diseases. 2011;52(5):e103-e120. doi:10.1093/cid/ciq257
  16. ↑ Colgan R, Williams M. Diagnosis and treatment of acute uncomplicated cystitis. Am Fam Physician. 2011 Oct 1;84(7):771-6.
  17. ↑ Acute Pyelonephritis in Adults. Johnson, JR and Russo, TA. New England Journal of Medicine 2018; 378:48-59.
  18. ↑ Sandberg T. et al. Ciprofloxacin for 7 days versus 14 days in women with acute pyelonephritis: a randomised, open-label and double-blind, placebo-controlled, non-inferiority trial. Lancet. 2012 Aug 4;380(9840):484-90.
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