Nephrolithiasis: Modern Diagnosis and Management

“I didn’t think getting stoned
would be so painful”
Nephrolithiasis – modern diagnosis and management
Carl Menckhoff, MD FACEP
Medical Director and Chair
Medical Center of Lewisville
Pathophysiology

Calcium oxalate:
70%
– Hypercalciuria


most are from jejunal hyperabsorption
Hyperparathyroidism
– Hyperoxaluria


tea, coffee, sodas, plums, rhubarb, cranberries,
citrus, green leafy veggies
Can occur with small bowel disease
Pathophysiology

Calcium phosphate:
10%
– a/w defects in urine acidification (RTA)

Struvite
(Magnesium-Ammonium-Phosphate)
:
10%
– a/w infections with urea splitting bacteria
(Klebsiella,
Serratia, Enterobacter, Pseudomonas, Proteus and Staph)

Uric acid:
10%
– Hyperuricosuria

Radiolucent ?
meat, fish, poultry
– a/w acid urine and hyperuricemia

Cystine:
1%
– a/w inborn disorder in reabsorption of cystine
Epidemiology
Incidence up to 12 %
 3 times more common in males
 70% occur between age 20 and 50
 Recurrence after 1st episode:

– 15-30 % @ 1 yr
– 50% @ 5-10 yrs
Risk Factors
20-50 years old
 Male
 Family history
 Hot, arid climates
 Sedentary

SO…………

Fat men between 20 & 50 who live in
Arizona.
Anatomy
UPJ 3 mm
Pelvic Brim 4 mm
UVJ 2 mm

<5% of stones > 8mm will pass

15% of stones 5-8 mm will pass

90% of stones < 5 mm will pass
Classic Hx:

Sudden onset of severe pain
– Pelvis/calyx

deep flank ache
– Ureter

severe colicky pain in flank, abdomen,
groin
– Distal ureter / Bladder


N/V
dysuria, frequency, urgency, retention
Classic PE:
Writhing
 Non-tender or mildly tender over
impaction
 Normal genital exam

DDx: Be sure to check:

fever
– infection (pyonephrosis, perinephric abscess)

hypotension
– AAA

abdominal distension, pulsatile masses,
bruits, peritoneal signs
– AAA, SBO, appendicitis, PID, renal artery
stenosis ……...
DDx: Be sure to check:

CVA tenderness
– pyelo, shingles, back strain

genitals/pelvic
– hernias, torsion, PID, epididymitis

lungs
– lobar pneumonia

skin
– Zoster

lower extremity pulses
– AAA
Labs:
 Urine
dip & Urinalysis
– RBCs (absent in 15-20%)
– WBCs or bacteria
– pH<5.0 suggests uric acid stone
– pH>7.6 suggests struvite stone
 Pregnancy
females)
test (just for the
Labs:

Others not routinely indicated:
– Electrolytes
prolonged symptoms, or renal
insufficiency
– CBC
– Serum calcium, phosphorus, uric acid

Imaging
What
are our options?
Imaging:

KUB:
– 90% of stones are radio-opaque
– low sensitivity and specificity




Sensitivity: <50 % when read by EPs
Specificity: 70%
– may be useful to monitor passage of a
known opaque stone
Pros: easy
Cons: low sensitivity and specificity

Imaging

US:
– sensitivity: 66-93% (70%)
– specificity: 83-100%
– look for:



stone, hydroureter, perirenal urinoma
Pros: no radiation (pregnancy), no contrast
Cons: low sensitivity compared to IVP and CT
Imaging:

KUB and US (either positive):

– sensitivity of 95%
– specificity of 67%
Pros: minimal radiation, good sensitivity
Cons: 2 studies, sensitivity/specificity not as
good as other modalities

Imaging

IVP:

– sensitivity: 64-97%
– specificity: 94-100%
Pros: sensitive and specific, can tell structural
and functional information
Cons: IV contrast, radiation, time, most techs
have never done one.

Imaging

IVP signs of obstruction
– delayed nephrogram (earliest & most reliable)
– hydronephrosis
– hydroureter
– standing column
– distension of renal pelvis
– calyceal distortion
– dye extravasation


Normal
Standing column

Imaging

CT scan

– sensitivity 94-100%
– specificity 96-100%
Pros: quick, no contrast, can see other
pathology
Cons: radiation, cost, no functional
information


Cost at MCL: CT $1012
IVP $472
Imaging

Renal stone CT signs:
– Calcification
– Hydroureter
– Perinephric stranding
– Dilation of the kidney / collecting system
Left hydronephrosis
Stone at left UPJ
So Who Needs to be Imaged?




Elderly
Signs of infection
Refractory symptoms
Decreased renal reserve
– comorbidities or underlying renal disease
– solitary kidney



Prolonged symptoms
Uncertain diagnosis
First time
Treatment:
NSAIDs
 Narcotics
 IV hydration?
 Anti-emetics
 -blocker (Flomax)
 CCB (nifedipine)?

When should we consult?
Infection without obstruction
 Stone unlikely to pass spontaneously
 Moderate to severe hydronephrosis
 Solitary kidney
 Intrinsic renal disease
 IVP with extravasation

When should we admit?
Infection with obstruction
 Refractory symptoms
 Solitary kidney with obstruction or large
stone
 Renal failure

So who gets to be discharged
without imaging?
 Young
 Healthy
 History
of stones
 No signs of infection
 Symptoms controlled
Discharge instructions:
po analgesia (NSAID + narcotic)
 Strain their urine / save stone
 All need to follow-up with PMD/urologist
in <1wk
 po hydration
 Return for fever, chills, refractory
symptoms

What Might We Be Missing?
Differential Diagnoses










AAA
ectopic
incarcerated hernia
cholecystitis
appendicitis
testicular torsion
ovarian torsion
shingles
pyelonephritis
intestinal obstruction









mesenteric ischemia
back strain
urinary tract tumor
renal papillary necrosis
blood clots from upper
tract hemorrhage
fungal aggregations
renal infarct
endometriosis
cervical cancer
What Might We Be Missing?

AAA
– 18% initially misdiagnosed as kidney stone
– all were > 60 years old

Borrero et al. Annals of Vascular Surg, 1988
What Might We Be Missing?

Renal artery or vein thrombosis
– flank pain, hematuria
– may have bruit
– no nephrogram
– no hydronephrosis

if suspected should get contrast CT or
angiogram
What Might We Be Missing?

Renal or perinephric abscess
– Flank pain, fever, mass
– Picked up on CT or US
What Might We Be Missing?

Renal papillary necrosis:
– flank pain, hematuria
– a/w diabetes, sickle cell, NSAID abuse
– ring shadows on IVP
– triangular lucency on CT
What Might We Be Missing?

Tumor:
– filling defect on IVP
(lucent stone?)
– mass on CT
Clinical Scenarios

Patient #1
– Hx: 33 yo male with sudden onset of R
flank pain. States he has a hx of stone
once 3 years ago. No meds. No allergies.

Patient #2
– Hx: 28 yo male with sudden onset of R
back pain radiating to R groin. Hx of stone.
No meds. No allergies.
Physical Exam

Patient #1
– young man writhing on the bed
– no findings on PE

Patient #2
– young man uncomfortable on the bed
– only finding is CVAT
What to do?

Patient #1:
– Urine shows mod blood and no white cells

Patient #2:
– Urine dip shows mod blood and trace leuks
Treatment

Patient #1:
– 2 L NS
– Pain controlled with ketorolac and meperidine

Patient #2:
– 2 L NS
– Pain controlled with ketorolac and meperidine
What now?

Patient #1 – See ya!
– Strainer
– Hydration
– Po analgesia (NSAID + narcotic)
– ? tamsulosin
– F/u with urology <1 wk
What now?

Patient #2
– UA shows 40 WBCs, 10-20 bacteria
– CT shows 8mm stone at pelvic brim and
moderate hydro on the R
What now?
Abx in the ED
 Urology consult:

– The urologist comes in, says thanks for
caring for this patient and admits him for
percutaneous drainage.

Patient #3
– 66 year old male c/o sudden onset of
colicky L flank pain radiating around to the
anterior abdomen
– PE shows obese male uncomfortable on
stretcher. Mild LUQ tenderness. No masses
palpated.
– Urine dip shows mod blood only
What now?

Labs are all normal

Imaging shows 7 cm aortic aneurysm just
below the renal vessels.

Vascular surgeon comes in. He says, “you
guys are awesome for picking this up,” and
takes him to the OR.
Pearls

What is the most common place for
impaction of a stone:

Answer: UVJ
Pearls

How long before a young, healthy
person with complete obstruction can
start to get irreversible kidney damage?

About 1 week
Pearls

What percent of stones > 8mm will
pass spontaneously?
<5% of stones > 8mm will pass
 15% of stones 5-8 mm will pass
 90% of stones < 5 mm will pass

The
End















REFERENCES
1. Trivedi B: Nephrolithiasis: How it happens and what to do about it. Nephrolithiasis 1996;100:63-78.
2. Ahlstrand C, Tiselius H: Recurrences during a 10-year follow-up after first renal stone episode. Urol
Res 1990;18:397-399.
3. Kerr WS Jr: Effect of complete ureteral obstruction for one week on kidney function. J Appl Physiol
1954;6:762-772.
4. Vaughan E, Gillenwater J: Recovery following complete chronic unilateral ureteral occlusion:
Functional, radiographic and pathologic alterations. J Urol 1971;106:27-35.
5. Shapiro S, Bennett A: Recovery of renal function after prolonged unilateral ureteral obstruction. J Urol
1976;115:136-140.
6. Okubo K, Suzuki Y, Ishitoya S, et al: Recovery of renal function after 153 days of complete unilateral
ureteral obstruction. J Urol 1998;160:1422-1423.
7. Borrero E, Queral LA: Symptomatic abdominal aortic aneurysm misdiagnosed as nephroureterolithiasis.
Ann Vasc Surg 1988;2:45-49.
8. Stewart D, Kowalski R, Wong P, Krome R: Microscopic hematuria and calculus-related ureteral
obstruction. J Emerg Med 1990;8:693-695.
9. Luchs J, Katz D, Lane M, et al: Utility of hematuria testing in patients with suspected renal colic:
Correlation with unenhanced helical CT results. Urology 2002;59:839-842.
10. Press S, Smith A: Incidence of negative hematuria in patients with acute urinary lithiasis presenting to
the emergency room with flank pain. Urology 1995;45:753-757.
11. Yilmaz S, Sindel T, Arslan S, et al: Renal colic: Comparison of spiral CT, US and IVP in the detection of
ureteral calculi. Eur Radiol 1998;8:212-217.
12. Fielding J, Steele G, Fox L, et al: Spiral computerized tomography in the evaluation of acute flank pain:
A replacement for excretory urography. J Urol 1997;157:2071-2073.
13. Dalrymple N, Verga M, Anderson K, et al: The value of unenhanced helical computerized tomography
in management of acute flank pain. J Urol 1998;159:735-740.
14. Boulay I, Holtz P, Foley W, et al: Ureteral calculi: Diagnostic efficacy of helical CT and implications for
treatment of patients. AJR Am J Roentgenol 1999;172:1485-1490.













15. Smith R, Verga M, McCarthy S, et al: Diagnosis of acute flank pain: Value of unenhanced helical CT.
AJR Am J Roentgenol 1996;166:97-101.
16. Colistro R, Torreggiani W, Lyburn I, et al: Unenhanced helical CT in the investigation of acute flank
pain. Clin Radiol 2002;57:435-441.
17. Sourtzis S, Thibeau J, Damry N, et al: Radiologic investigation of renal colic: Unenhanced helical CT
compared with excretory urography. AJR Am J Roentgenol 1999;172:1491-1494.
18. Hill M, Rich J, Mardiat J, et al: Sonography vs excretory urography in acute flank pain. AJR Am J
Roentgenol 1985;144:1235-1238.
19. Patlas M, Farkas A, Fisher D, et al: Ultrasound vs CT for the detection of ureteric stones in patients
with renal colic. Br J Radiol 2001;74:901-904.
20. Gorelik U, Ulish Y, Yagil Y: The use of standard imaging techniques and their diagnostic value in the
workup of renal colic in the setting of intractable flank pain. Urology 1996;47:635-642.
21. Mutgi A, Williams J, Nettleman M: Utility of the plain abdominal roentgenogram. Arch Intern Med
1991;151:1589-1592.
22. Roth C, Bowyer B, Berquist T, et al: Utility of the plain abdominal radiography for diagnosing ureteral
calculi. Ann Emerg Med 1985;14:311-315.
23. Palma L, Stacul F, Bazzocchi M, et al: Ultrasonography and plain film versus intravenous urography in
ureteric colic. Clin Radiol 1993;47:333-336.
24. Perlmutter A, Miller L, Trimble LA, et al: Toradol, an NSAID used for renal colic, decreases renal
perfusion and ureteral pressure in a canine model of unilateral ureteral obstruction. J Urol 1993;149:926930.
25. Lennon G, Bourke J, Ryan P, et al: Pharmacological options for the treatment of acute ureteric colic. Br
J Urol 1993;71:401-407.
26. Jasani NB, O’Conner RE, Bouzoukis JK: Comparison of hydromorphone and meperidine for ureteral
colic. Acad Emerg Med 1994;1:539-543.
27. Cordell W, Larson T, Lingeman J, et al: Indomethacin suppositories versus intravenously titrated
morphine for the treatment of ureteral colic. Ann Emerg Med 1994;23:262-269.












28. Labrecque M, Dostaler L, Rousselle R, et al: Efficacy of non-steroidal anti-inflammatory drugs in the
treatment of acute renal colic. Arch Intern Med 1994;154:1381-1387.
29. Lundstam SO, Leissner KH, Wåhlander LA, Kral JG: Prostaglandin-synthetase inhibition with diclofenac
sodium in treatment of renal colic: Comparison with use of a narcotic analgesic. Lancet
1982;1(8281):1096-1097.
30. Larkin G, Peacock W, Pearl S, et al: Efficacy of ketorolac tromethamine versus meperidine in the ED
treatment of acute renal colic. Am J Emerg Med 1999;17:6-10.
31. Cordell W, Wright S, Wolfson A, et al: Comparison of intravenous ketorolac, meperidine, and both
(balanced analgesia) for renal colic. Ann Emerg Med 1996;28:151-158.
32. Dellabella M, Milanese G, Muzzonigro G: Efficacy of tamsulosin in the medical management of
juxtavesical ureteral stones. J Urol 2003;170:2202-2205.
33. Duquenne S, Hellel M, Godinas L, et al: Spasmolytics indication in renal colic: a literature review. Revue
Medicale de Liege 2009:64(1):45-8.
34. Singh A, Alter H, Littlepage A: A systematic review of medical therapy to facilitate passage of ureteral
calculi. Annals of Emergency Medicine 2007:50(5):552-63.
35. Dellabella M, Milanese G, Muzzonigro G: Randomized trial of the efficacy of tamsulosin, nifedipine and
phloroglucinol in medical expulsive therapy for distal ureteral calculi. Journal of Urology 2005:174(1):16772.
36. Yencilek F, Erturhan S, Canguven O, et al: Does tamsulosin change the management of proximally
located ureteral stones? Urological Research 2010:38(3):195-9.
37. Welk B, Teichman J: Pharmacological management of renal colic in the older patient. Drugs & Aging
2007:24(11):891-900.
38. Troxel S, Jones C, Magliola, et al: Physiologic effect of nifedipine and tamsulosin on contractility of
distal ureter. Journal of Endourology 2006:20(8):565-8.
39. Edna T, Hesselberg F: Acute ureteral colic and fluid intake. Scand J Urol Nephrol 1983;17:175-178.