Urinary Tract Disorders

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Urinary Tract Disorders

• May 12, 2005

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Objectives

• Distinguish types of UTI, including bacteriuria,
  urethritis, cystitis, and pyelonephritis
• Describe the pathophysiology related to UTI, such
  as organisms and host factors
• Describe pathophys of common forms of
  nephrolithiasis, including risk factors for
  development of nephrolithiasis
• Describe typical clinical presentations, and
  elicit a pertinent history, in a patient with UTI
  or nephrolithiasis
• Describe the diagnostic methods and diagnostic
  criteria for the various types of UTI
• Summarize the methods used for dx of
  nephrolithiasis
• Describe modes of therapy for acute, chronic, and
  complicated UTI, including prophylaxis for
  recurrent infection
• Summarize therapeutic options for
  nephrolithiasis, and strategies to prevent
  recurrence

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Urinary Tract Infection

• Lower
• urethritis
• cystitis
• prostatitis
• Upper
• pyelonephritis
• intrarenal and perinephric abscess

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Also categorized into

• Non-catheter associated (commum. acquired)
• Catheter associated (hosp. acquired)
• Any category may be sx or asx

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Urinary Tract Infection

• Pathogenic microorganisms in urine, urethra,
  bladder, kidney, prostate
• Usually growth gt 105 organisms per milliliter
• From midstream clean catch urine sample
• If sx or from catheter specimen can be
  significant with 102 or 104 organisms per mL

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Etiology

• Most common is Gram neg. bacteria
• E. coli 80 of uncomp. acute UTI
• Proteus assoc. with stones
• Klebsiella assoc. with stones
• Enterobacter
• Serratia
• Pseudomonas

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Etiology

• Gram pos. cocci
• Staphylococcus saprophyticus 10-15 acute sx UTI
  in young females
• Enterococci occas. in acute uncomp. cystitis
• Staphylococcus aureus assoc. with renal stones,
  instrumentation, increased susp. of bacteremic
  kidney infection

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Etiology

• Urethritis from chlamydia, gonorrhea, HSV acute
  sx female with sterile pyuria
• Ureaplasma urealyticum
• Candida or other fungal species commonly assoc.
  with cath. or DM
• Mycobacteria

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Pathogenesis

• Usually ascent of bacteria from urethra to
  bladder to kidney
• Vaginal introitus, distal urethra colonized by
  normal flora
• Gram negative bacilli from bowel may colonize at
  introitus, periurethra

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?Predisposing conditions to UTI

• Female
• Short urethra, proximity to anus, termination
  beneath labia
• Sexual activity
• Pregnancy
• 2-3 have UTI in preg, 20-30 with asx
  bacteriuria ? may lead to pyelo
• Increased risk of pyelo decreased ureteral
  tone, decreased ureteral peristalsis, temp.
  incomp of vesicoureteral valves

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?Predisposing conditions

• Neurogenic bladder dysfunction or bladder
  diverticulum (incomplete emptying)
• Age - Postmenopausal women with uterine or
  bladder prolapse (incomplete emptying), lack of
  estrogen, decreased normal flora, concomitant
  medical conditions such as DM
• Vesicoureteral reflux
• Bacterial virulence
• Genetics
• Change in urine nutrients, DM, gout

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Urethritis ?

• Acute dysuria, frequency
• Often need to suspect sexually transmitted
  pathogens esp. if sx more than 2 days, no
  hematuria, no suprapubic pain, new sexual
  partner, cervicitis

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Cystitis

• Sx frequency, dysuria, urgency, suprapubic pain
• Cloudy, malodorous urine (nonspec.)
• Leukocyte esterase positive pyuria
• Nitrite positive (but not always)
• WBC (2-5 with sx) and bacteria on urine microscopy

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Pyelonephritis

• Fever
• chills, N/V, diarrhea, tachycardia, gen. muscle
  tenderness
• CVAT or tenderness with deep abdominal tenderness
• Possibly signs of Gram neg. sepsis

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?Pyelonephritis

• Leukocytosis
• Pyuria with leukocyte casts, and bacteria and
  hematuria on microscopy
• Complications sepsis, papillary necrosis,
  ureteral obstruction, abscess, decreased renal
  function if scarring from chronic infection, in
  pregnancy may increase incidence of preterm
  labor

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Catheter-Associated ?
Urinary Tract Infections

• 10-15 of hosp. patients with indwelling catheter
  develop bacteriuria
• Risk of infection is 3-5 per day of
  catheterization
• UTI after one-time bladder cath approx. 2
• Gram neg. bacteremia most significant
  complication of cath-induced UTI
• Greater antimicrobial resistance

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Diagnosis of UTI

• History
• Physical exam
• Lab
• Urinalysis with micro WBC, bacteria
• Urine culture
• Sensitivities of culture for tailored antibiotic
  therapy
• May dx acute uncomp. cystitis based on hx, PE,
  and UA alone, no need for culture to treat

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Diagnosis

• Urinalysis
• Leuk. Esterase pos. pyuria
• Nitrite pos. from urea prod. bact. (but not
  always)
• Micro WBC (even 2-5 in patient with sx)
• Micro Bacteria

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Diagnosis

• Urine culture
• Once 105 colonies per mL considered standard for
  dx but misses up to 50
• Now, 102 to 104 accepted as significant if
  patient symptomatic
• Needed in upper UTI, comp. UTI, and in failed
  treatment or reinfection
• Sensitivities for better tailoring of tx

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Treatment ?

• Uncomp. cystitis with less than 48 hours of sx,
  non-pregnant, usu. 3 days tx sufficient
• Bactrim DS, Septra DS
• Cipro or other FQ (avoid in preg.)
• Nitrofurantoin (7 days)
• Augmentin
• Bladder analgesis, Pyridium

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Treatment

• Uncomp. cystitis in pregnant patient
• Requires longer tx of 7-14 days
• Cephalosporin, nitrofurantoin, augmentin,
  sulfonamides (do not use near term, inc.
  kernicterus)

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Asymptomatic ?
Bacteriuria

• 105 org/mL growth
• Empiric treatment of all asymptomatic bacteriuria
  (ASB) in pregnancy. Screening at first visit.
• ASB if untreated inc. PTD and LBW, 20-30
  develop pyelo.
• Do TOC in 2 weeks and each trimester.
• Screen Sickle cell trait each trimester. Twofold
  inc. risk of ASB

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Asymptomatic Bacteriuria

• Treatment failures repeat tx based on
  sensitivities for 1 week, then prophylactic
  therapy for remainder of pregnancy
• Prophylaxis Nitrofurantoin, Ampicillin, TMP/SMX

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Treatment Recurrent uncomp. UTI

• 3 or more episodes in one year, 2 in 6 months
• Bactrim DS ( or septra DS) QD for 3-6 months
  once infection eradicated, self-admin. Single
  dose at symptom onset or one DS tab post-coitus
• Measures for prevention voiding after
  intercourse, good hydration, frequent and
  complete voiding

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Treatment of Pyelonephritis -- Outpatient

• Uncomp. Nonpreg pyelo
• Primary any FQ x 7 days, cipro
• Alt. -- Augmentin, TMP/SMX, or oral CSP for 14
  days

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Treatment ofPyelonephritis Inpatient ?

• Treat IV until patient is afebrile 24-48 hours.
  Then, complete 2 week course with PO meds
• Use FQ or amp/gent or ceftriaxone or piperacillin
• If no improvement on IV, consider imaging studies
  to look for abscess or obstruction
• All pregnant patients with pyelo get inpatient
  tx, appropriate IV antibiotics immediately

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Treatment of Complicated UTI

• Catheter related
• Amp/gent or Zosyn or ticaricillin/clav or
  imipenem or meropenem x 2-3 weeks
• Switch to PO FQ or TMP/SMX when possible
• Rule out obstruction
• Watch out for enterococci and pseudomonas

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Nephrolithiasis ?

• Supersat. of urine by stone forming constituents
• Crystals of foreign bodies act as nidi
• Freq. stone types Calcium (most common),
  struvite, oxalate, uric acid, staghorn
• Risk factors metabolic disturbances, previous
  UTI, gout, genetic

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Nephrolithiasis

• Incidence 2-3
• Morbidity
• Obstruction ? pain
• Chronic obstruction, may be asx ? loss of renal
  function
• Hematuria (rarely dangerous by itself)
• Dangerous combo obstruction infection

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Nephrolithiasis ?

• More prev. in Asians and whites
• Males gt females, 31
• Struvite stones from infection, increased in
  females
• Ages 20-49
• Recurrent
• Uncommon after 50 y.o.

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Nephrolithiasis Patient History ?

• Often dramatic pain, poss. infection, hematuria
• Even nonobst. May cause sx
• Bladder irritating sx
• Renal colic because of stone in ureter
• Severe, undulating cramps because of ureter
  peristalsis, sever pain, N/V
• Pain may migrate

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Nephrolithiasis Patient History

• Duration, char, location of pain
• Hx of stones?
• UTI?
• Loss of renal function?
• FHx of stones
• Solitary/ transplanted kidney

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Nephrolithiasis Physical Exam

• Dramatic CVAT, may migrate as stone moves
• Usu. Lacking peritoneal signs
• Calculus often in area of maximum discomfort

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Nephrolithiasis Workup

• Urinalysis
• Evid. Of hematuria and infection
• 24-hour urinalysis helpful in identifying cause
• CMP, uric acid, CBC
• Calcium, oxalate, uric acid in the 24 hour urine

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Nephrolithiasis Workup

• Plain abd film (KUB)
• Renal USG
• IVP
• Helical CT without contrast (stone protocol)

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Nephrolithiasis Treatment

• If no obstruction or infection, stones lt 5-6mm
  may likely pass
• Restore fluid volume if dehyd.
• Analgesics narcotics, nsaids
• Antiemetics
• Occasionally nifedipine (CCB) to relax ureteral
  smooth muscle and prednisone used
• Urology consult

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Nephrolithiasis Treatment ?

• Surgical intervention (call urology)
• Extracorporeal shock-wave lithotrypsy (not in
  pregnancy)
• Ureteral stent
• Percutaneous nephrostomy
• Ureteroscopy
• Indications pain, infection, obstruction
• Contraindications active untx infection,
  uncorrected bleeding diathesis,
• pregnancy (relative)

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Nephrolithiasis Prophylaxis ?

• Increase fluid intake (2 liters per day of UOP)
• 24 hour urine, eval calcium, oxalate, uric acid
  to determine dietary prevention
• metabolic tests to determine cause (Ex
  hyperparathyroidism)
• Decrease salt intake

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References

• Braunwald et al. (2002) Harrisons Principals of
  Internal Medicine (15th edition). New York
  McGraw-Hill.
• Ling F., Duff, P. () Obstetrics and Gynecology,
  Principles for Practice. 2001. New York
  McGraw-Hill.
• www.emedicine.com
• ACOG Practice Bulletin, Clinical Mgmt Guidelines
  (No 23, Jan 2001). Antibiotic Prophylaxis for Gyn
  Procedures
• Brankowski et al. The Johns Hopkins Manual of
  Obstetrics and Gynecology. 2002. Philadelphia
  LWW
• The Sanford Guide to Antibiotic Therapy