Urologic Stone Disease
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Transcript Urologic Stone Disease
Urologic Stone Disease
Tintinalli Chapters 96-97
Randall Adolph
Epidemiology
• 3:1 M:F (~7% men/ 3% women)
• 3rd-5th decade most common (70%)
• Hereditary predisposition (RTA type 1, Hyperparathyroidism, cysteinuria, milk-alkali
syndrome, sarcoidosis, Crohn's disease)
• Climate (mountainous, desert, or tropical)
• Time of year (warmest three months)
• Lifestyle (sedentary)
• Medications: protease inhibitors, carbonic
anhydrase inhibitors, laxatives, triamterene
Patient Characteristics
• <16 year old comprise 7% of cases
• 1:1 M:F
• Causes: metabolic abnormalities 50%,
urological abnormalities 20%, infection
15%, immobilization 5%
• 1/3 have recurrence within 1 year
• 50% within 5 years
Pathophysiology
•
Formation requires three key elements
1. Supersaturation of urine with solutes
2. Relative lack of the inhibitors citrate &
pyrophosphate
3. Stasis or lack of urine flow
•
Composition:
1. 75% calcium oxalate
2. 10% staghorn calculi (struvite): associated with
urease-splitting bacteria, poor Ab. penetration
and usually require surgery
3. Uric acid stones 10%
Composition Continued
• Calcium oxolate Hyperoxaluria occurs in
the presence of small bowel disease-Crohn's disease, ulcerative colitis, and
radiation enteritis.
• Uric Acid10% of all stones
– excessive excretion of uric acid in the urine
– increases with uricosuric agents
– Radiolucent!!!
Obstruction leads to:
• Rapid redistribution of renal blood flow, ↓
glomerular filtration rate renal excretion shifts
to unaffected kidney
• Causes rapid decrease in ureteral peristaltic
activity
• Complete obstruction may lead to loss of renal
function
• Increased occurrence of irreversible damage
after 1 to 2 weeks of obstruction
• Partial obstruction lower likelihood of renal injury,
may still result in irreversible damage.
Critical size
• 5 mm~ 90% < 5 mm and located in the
lower ureter pass spontaneously
• 15% pass if between 5 and 8 mm
• 95% >8 mm become impacted generally
requiring lithotripsy or surgical removal
• 75% of stones are located in the distal
third of the ureter
Area of impaction
• Renal calyx
• UPJ, where ureter passes over pelvic brim
and iliac vessels
• UVJ: smallest diameter of the urinary tract
• In FM the posterior pelvis: ureter is
crossed anteriorly by the pelvic blood
vessels and broad ligament
Places for obstruction
Causes of pain
• Colicky, severe flank pain: hyperperistalsis
of smooth muscle of the calyces, pelvis,
and ureter
• Dull ache: attributed to acute obstruction
and renal capsular tension
Clinically
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Usually asymptomatic until obstructs
acute onset severe pain, typically at rest
little if any POP
Typically flank, abdomen with referral to
ipsilateral labia or testicle
• May be writhing in pain, reluctant to lie still
• Episodic as passes, pain free until
obstructs more distally
Urinary pH
• pH> 7.6 suspicious for urea-splitting
organisms because the kidney will not,
under normal conditions, produce urine in
this alkaline range.
• pH < 5 often associated with the formation
of uric acid calculi.
LABORATORY
• UA hematuria supports diagnosis,
absent in 15% ;crystals seen w/wo stones
• Dipstick detects heme, myoglobin and
porphyrins, need micro (see RBCs)
• Urine C&S,
• BUN & Creatinine especially if imaging
with RCM, higher rates of complications in
DM >1.5, CRF >2.5
Imaging
• performed with a first episode of renal
colic.
• Other indications:
– Diagnosis is unclear
– Those in whom a proximal UTI, in addition to
a calculus, is suspected.
• A KUB is the standard, initial radiograph
done before injecting contrast media
during IVP.
Imaging
• Helical CT preferred modality
• US if pregnant
• Others IV urography, Radionuclide renal
scan, plain abd. Film
• Shows stone, location, IDs complications
• Unilateral ureteral dilatation and
perinephritic stranding together: PPV 96%
• Both absent NPV 93-97%
Noncontrast CT
• Advantages: fast, avoids RCM,
• Disadvantages: specificity/sensitivity low
for other pathologies (AAA, appendicitis)
• Does not evaluate renal function or degree
of obstruction
• If negative may need RCM to look for
other cause of pain
IV Urography
• Indicators of obstructing stone:
– 1st and most reliable indicator of obstruction is
a delayed nephrogram in the 5-minute film
– Visualization of the entire ureter is suggestive
of obstruction
– Ureteral contrast column cutoff, prolonged
nephrogram, renal enlargement, dilatation of
the collecting system, contrast extravastation
Helical CT
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Advantages: provides info on function
Disadvantages: uses RCM (allergy,nephrotoxic)
Nephrotoxicity: 9% in pts. with RI or DM
BUN, Creatinine before RCM
Metformin & RCM severe Lactic acidosis,
nephrotoxicity
• False negative if stone small, radiolucent,
partially obstructing, or passes into bladder
before contrast passed by kidneys
US
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During pregnancy, children
May misses stones < 5mm
Less sensitive in middle ureter
Overall low sensitivity/specificity for stones
98% sensitive for hydronephrosis,
however 22% of cases not associated with
obstruction
US
• Advantages:
– noninvasive, no dyes or radiation, no known
side effects
– Superior to IVU for UVJ stones
• Disadvantages:
– excretion function not evaluated operator and
equipment dependant
– obesity may hinder ability to perform
Plain Films
• 90% stones radiopaque (Ca > Struvite >
Cystine)
• Uric acid and stones associated with
medications radiolucent
• Overall poor Sensitivity & Specificity
• Greatest utility is excluding other
pathologies
Stone gone wild
• infection occasionally occurs in the
presence of an obstructive stone.
• A history of fever and chills strongly
suggests superimposed infection and is a
urologic emergency. It is imperative to do
an IVP or an ultrasound study in these
cases
• Sterile pyuria strongly suggests renal
tuberculosis; confirmation acid-fast bacilli
Differential Diagnosis
• Aortic dissection , AAA
• Appendicitis: usually don’t see rebound,
guarding, distention with stone
• Infectious: fever with CVA, consider
pyelonephritis
• Papillary necrosis: DM, SCD, NSAID abuse; see
Hematuria and pyuria
• Vascular:Renal vein thrombosis, Mesenteric
ischemia
• Gynecological
vascular etiology
• If suspected, a contrast CT or angiogram done.
• Relatively rare: m/c renal artery embolism, most
often of cardiac origin (atrial fibrillation, subacute
bacterial endocarditis, mural thrombus)
• IVP should demonstrate decreased or absent
excretion of contrast material. Immediate
angiogram indicated early diagnosis allows
possible salvage of the ischemic kidney
Predisposing factors for renal vein thrombosis
include the nephrotic syndrome, malignancies,
and pregnancy
TREATMENT
• Pain control: Opiods and nsaids
• NSAIDs: analgesic, decrease ureterospasm
and renal capsular pressure by diminishing
GFR in the obstructed kidney.
• Obstruction with Infection: Urology
emergency
• Consult if: RI, Severe underlying disease,
extravasation or complete obstruction,
Multiple ED visits, large stone, sloughed renal
papillae
Management
• Average time to pass stone varies (7-20 days)
• Long acting CCB (Nifedipine) and steroids may
enhance passage
• F/U Urology in 7 days
• Stone saved/submitted to urologist for analysis.
• Dispo: return immediately if intractable, severe
pain, persistent nausea and vomiting, fever and
chills
Indications for Admission
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Obstruction with infection
Persistent pain
Persistent nausea and vomiting
Urinary extravasation
Hypercalcemic crisis
Relative Indications for Admission
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High-grade obstruction
Solitary kidney
Intrinsic renal disease
Size of obstructing stone
Duration of symptoms
Social situation
Admit
• severely dehydrated
• unrelenting pain or vomiting
• underlying infection with hydronephrosis
Bladder stones
• different from renal stones
• almost exclusively elderly men
• most often complication of other urologic
disease (Proteus).
• The other common indwelling catheter
• May complain of sudden interruption of the
urinary stream. This strongly suggests a
vesical stone that intermittently obstructs
the bladder outlet
Hematuria and Hematospermia
• Tintinalli Chapter 97
Hematuria
• Definition:
– >5 RBCs/hpf warrants an attempt at definitive diagnosis
• Timing:
– Initial suggests urethral disease
– B/n voiding and only staining undergarments, with clear urine
distal urethral or meatus
– Total disease of kidneys, ureters, or bladder
– Terminal bladder neck or prostatic urethra
• Amount
– Gross hematuria lower tract cause while microscopic tends to
be kidney disease
• Color:
– Brown/Smokey colored with casts and proteinuria suggests
glomerular
– Red clotted blood indicates source below kidney
HEMATURIA
• a harbinger of serious urologic disease
• Gross hematuria 5X more likely to have lifethreatening conditions when compared to those with
microhematuria.
• Lower and middle urinary tract ~60%
• Urologic malignancies 2.2% to 12.5% with
microscopic hematuria, up to 20% if > 50 years with
gross hematuria.
• Gross hematuria (>3 red blood cells/hpf on two of
three urinalyses found a potentially life-threatening
lesion in 9.1% of these patients.
Hematuria
• Young Pts. most often urolithiasis or UTI
• Consider glomerulonephritis, goodpasture,
HSP, Wilms Tumor, SCD/trait
• PSGN 7-14 days following pharyngitis,
Abs do not prevent this
• IgA nephropathy following viral URI
• Elderly: infection, Nephroolithiasis,
bladder, prostate, renal CA
Other sources of bleeding
• infection of the bladder (hemorrhagic
cystitis)
• varices of the bladder
• Diverticula
• bladder stones
• postradiation changes
• Anticoagulation at currently recommended
levels does not predispose patients to
hematuria
Risk factors for Uroepithelial CA
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Age >40
Excessive analgesic use
Smoking
Exposure to dyes, benzenes, aromatic amines
Pelvic irradiation
Cyclophosphamide
Hematuria in patients on blood thinners, have
underlying disease 80% of the time
glomerular and nonglomerular
• glomerular origin: frequently associated
with dysmorphic erythrocytes, RBC casts,
and significant proteinuria (2+ to 3+)
• IgA nephropathy (Berger's disease) m/c,
cause
• nonglomerular hematuria: uniformly round
erythrocytes and absence of erythrocyte
casts and proteinuria.
glomerular disease
• Typically young males have hematuria, erythematous
skin rash, and fevers suggesting immunoglobulin
nephropathy, or Berger's disease
• Family history of deafness, renal disease, and hematuria
is linked to Alport nephritis.
• A rash, arthritis, and hematuria are seen with systemic
lupus erythematosus.
• Hematuria, hemoptysis, and microscopic anemia are
common presentations of Goodpasture's syndrome.
• A preceding upper respiratory infection, pharyngitis, skin
infection, or rash with associated hematuria suggests
poststreptococcal glomerulonephritis.
nonglomerular disease
• A family history of bleeding disorders or
renal cystic disease suggest hemophilia
and polycystic kidney disease,
respectively.
• Suspect papillary necrosis in diabetics,
sickle cell patients, and analgesic abusers
(Classic urolithiasis, sudden flank pain and
hematuria)
Diagnosing
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Clarify symptoms and source:
traumatic/atraumatic
Gross/micro
Initial/total/terminal
Associated symptoms: flank pain, menstruation, dysuria,
etc.
• Travel (schistosomiasis)
• Abnormal RBC morphology, casts, protein suggest
glomerular source
• Strenuous exercise frequently cause, but deserves
investigation even if spontaneously resolves
Exercise-Induced
• Exercise-induced hematuria that does not
resolve after 48 hours commonly results
from punctate hemorrhagic lesions
suggesting bladder cancer
• Diagnosed by cystoscopy
dipstick
• positive only if there has been lysis of
RBCs or with myoglobinuria.
• [Hemoglobin] greater than 0.003 mg/L
(10,000 red blood cells/mm3 or 1 to 2
RBCs/hpf)
• Current recommendations: urinalysis and
cytology for 3 consecutive years if
resolution of hematuria or persistent
asymptomatic microhematuria
• ross hematuria should be reevaluated in
all instances
Renal Imaging
• IVP clearly delineates most renal tumors,
obstruction, or stones and their precise location
– Disadvantage: RCM, does not assess aorta,
retroperitenium and pelvis
• Helical CT fast highly sensitive and specific for
stone, RCM used for other pathologies
• Renal US to screen for AAA, Hydro, obstruction.
Study of choice in Pregnant and children
– Disadvantages: rarely identifies small stones, no idea
of functioning,
Treatment
• Abs. for infection
• Pain meds. & hydration for nephrolithiasis
• D/C only if asymptomatic, tolerating PO, Abs. &
analgesics & no sig. comorbidities
• <40 to PCP for repeat UA 1-2 weeks, if persists
or >40 and risk for CA, Urology for cystoscope
• Asymptomatic microscopic hematuria associated
with a 2 fold increase of future RF
• Proteinuria: a sign of prognostically significant
glomerular disease & needs further workup
Complications
• Gross hematuria may lead to intravesical
clot and subsequent outflow obstruction
• New glomerulonephritis: at risk for
Pulmonary edema, volume overload,
azotemia or HTN emergency need
admission
• Pregnant: May be preeclampsia,
pyelonephritis, obstructing stone call OB
and possibly admit
Hematospermia
• Trauma, injury (tumor with erosion),
inflammation, infection of ejaculatory system
• M/C iatrogenic from instrumentation, radiation.
• >40 prostate CA, BPH considerations
• <40 prostatitis, seminal vesiculitis, urethritis,
STD, epididymo-orchitis, calculi, TB
• UA warranted
• Usually benign, but urology referral indicated
Questions?
Question 1
•
What season is associated with an
increased incidence of stones?
a)
b)
c)
d)
Winter
Spring
Summer
Fall
Answer C
Question 2
• True or false: Hematuria seen in a patient
on therapeutic levels of blood thinners is
usually microscopic and benign?
False: underlying pathology 80% of time
Question 3
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In the ED what is a value fror defining
hematuria?
a)
b)
c)
d)
Answer: D
Any RBCs/hpf
2 RBCs/hpf
4 RBCs/hpf
5 RBCs/hpf
Question 4
•
The most common cause of stone
formation is?
a)
b)
c)
d)
a)
metabolic abnormalities
urological abnormalities
infection
Immobilization
Answer: A 50%
Question 5
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What is the most common composition of renal
stones?
a)
b)
c)
d)
Uric acid stones
struvite
calcium oxalate
Magnesium
Answer: C