UTI

Question 1

UTI Predisposing Factors

Answer 1

• Obstruction: BPH, urethral structure, tumors, calculi, bladder diverticula
• Incomplete emptying: SCI, DM, stroke, neuropathies
• Reflux: over-distension, congenital, vesicoureteral reflux
• Intercourse: diaphragms, spermicides
• Urinary catheterization
• Pregnancy
• Previous UTI

Question 2

Host Defense

Answer 2

• Normal urinary tract: urine pH, osmolality, high [urea/organic acid], and prostate secretion
• Stimulation of micturition by bacteria
• Anti-adherence: Mucopolysaccharide, Tamm-Horsfall protein, immunoglobulins
• Inflammatory response
• Vaginal flora, estrogen

Question 3

Common Pathogens

Answer 3

• E. Coli
• K. pneumoniae
• Proteus spp
• P. aeruginosa
• S. saprophyticus
• Enterococcus spp.

Question 4

Virulence Factors

Answer 4

• Organism’s degree of pathogenicity
• Adhesion mechanisms like fimbriae
• Hemolysin: ruptures RBCs
• Aerobactin allow organism to absorb iron

Question 5

Fimbriae

Answer 5

• Hair like structure allowing binding to cell wall

- Mannose resistant, P-fimbriae binds to uroepithelial cells and is more likely to cause kidney stones

Question 6

Routes of Infection

Answer 6

• Hematogenous: uncommon, bacteria carried elsewhere in the body through the blood and seeds infection
• Ascending: common, colonization of urethra with fecal flora leading to infection
• Lymphatic: unknown incidence, limited amount of data

Question 7

Diagnosis

Answer 7

• Based on presence of symptoms and supported by urinalysis or urine culture
• Asymptomatic UTI: presence of bacteria without symptoms

Question 8

Cystitis UTI symptoms

Answer 8

• Lower UTI
• Dysuria
• Urgency
• Frequency
• Suprapubic tenderness

Question 9

Pyelonephritis UTI Symptoms

Answer 9

• Upper UTI
• Flank pain
• Fever
• Nausea
• Vomiting
• Malaise
• CVA tenderness

Question 10

Catheter Associated UTI Symptoms

Answer 10

• Compatible with UTI + urethral/suprapubic/intermittent catheterization
• > 10^2 cfu/mL of bacteria in fresh catheter urine culture

Question 11

Clean Catch

Answer 11

• Preferred urine specimen collection method
• Least invasive
• Discard first 20-30 mL voided
• Requires clean urethral opening

Question 12

Alternative Urine Collection

Answer 12

• Catheterization: for uncooperative or unable to void patients
• Suprapubic bladder aspiration: used in newborns, infants, paraplegics, and seriously ill patients when other methods have failed

Question 13

Urinalysis

Answer 13

• Nitrates: present when bacteria reduces urinary nitrates
• LCE: produced by neutrophils
• Squamous cells: >= 20 then sample likely contaminated
• WBCs: shows GU inflammation and if >= 10 then may indicate a UTI
• Bacteria/yeast: could be normal flora, contaminant, or sign of UTI

Question 14

Urine Culture

Answer 14

• Most reliable way to diagnose UTI

- Quantity of colony forming units to confirm infection: >= 10^5 of single strain

Question 15

Cranberry

Answer 15

• No conclusive data that it prevents UTI

- Potential benefit may be more related to hydration vs cranberry itself

Question 16

Asymptomatic Bacteria

Answer 16

• Only treat if pregnant or with pending GU procedure

- Options: Macrobid, Augmentin, Cephalexin, Fosfomycin, or Bactrim

Question 17

Asymptomatic Bacteria + Drug Doses

Answer 17

• Macrobid: 100 mg PO BID x 5-7 days (don’t use if at term, 1st trimester, or pyelonephritis)
• Augmentin: 875/125 mg PO BID x 5-7 days
• Cephalexin: 500 mg PO BID x 5-7 days
• Fosfomycin: 3g PO as single dose (don’t use if pyelonephritis suspected)
• Bactrim 1 DS PO BID x 3-7 days (avoid in 1st or late 3rd trimester)

Question 18

Uncomplicated Cystitis

Answer 18

• Don’t need initial urine culture

- Health women: 12-45 y.o., premenopausal, not preggo, no structural abnormalities

Question 19

Uncomplicated Cystitis Treatments

Answer 19

• Macrobid: 100 mg PO BID x 5 days
• Bactrim: 1 DS tablets PO BID x 3 days
• Fosfomycin: 3g powder PO x 1 dose
• Augmentin: 500/125 mg PO TID x 5 days
• Cefdinir: 300 mg PO BID x 5 days
• Cefpodoxime: 100 mg PO BID x 5 days
• Ciprofloxacin: 250 mg PO BID x 3 days
• Levofloxacin: 250 mg PO q24h x4days

Question 20

What NOT to use empirically for Uncomplicated Cystitis

Answer 20

• Amoxicillin

- Ampicillin

Question 21

Complicated Cystitis

Answer 21

• All adults who don’t meet uncomplicated criteria
• Usually from structural abnormality
• Treatment depends on severity, is the same as pyelonephritis
• Duration: 7-10 days

Question 22

Mild-Mod. Pyelonephritis

Answer 22

• Fever and CVA tenderness
• May treat with oral regimens and outpatient
• Obtain UA, urine, and blood cultures

Question 23

Mild-Mod. Pyelonephritis Treatments

Answer 23

• Cipro: 500 mg PO BID x 7 days
• Levofloxacin: 500 mg PO daily x 7 days
• Bactrim: 1 DS PO BID x 3 days
• Augmentin: 875/125 mg PO BID x 10-14 days
• Cephalexin: 500 mg PO QID x 10-14 days
• Ceftriaxone: 1-2g IV daily

Question 24

Severe Pyelonephritis

Answer 24

• Fever > 38.3 C
• Severe flank pain
• N/V, dehydration, hemodynamic instability, sepsis
• Treat inpatient with IV
• Obtain UA, urine, and blood cultures
• Can switch to PO once afebrile x 24-48 hours
• Duration: 10-14 days
• Repeat cultures should be considered after treatment to ensure resolution of infection
• Adjust treatment based on culture results

Question 25

Severe Pyelonephritis Parenteral Treatment

Answer 25

- Zosyn: 4.5g IV q6h - Cipro: 400 mg IV q12h - Levofloxacin: 500 mg IV q24h - Ceftriaxone: 1g IV q24h - Cefepime: 2g IV q8h

Question 26

Severe Pyelonephritis Oral Treatment

Answer 26

- Cipro: 500 mg PO BID - Levofloxacin: 500 mg PO daily - Bactrim: 1 DS PO BID

Question 27

CAUTI

Answer 27

- Catheter-Associated UTI - Plastic tubing promotes bacteria growth and formation of biofilms - Urine samples from old catheters won't give accurate cultures - Change catheter every 2 weeks - Treat based on pathogens/susceptibilities - Duration: 7 days if prompt resolution of symptoms or 10-14 days for delayed response

Question 28

Adjuvant Therapy

Answer 28

- Phenazopyridine HCl - OTC: anesthetic and analgesic to relieve symptoms - 100-200 mg TID after meals x 2 days + APPROPRIATE ABX - Secretions may change to a red-orange and permanently stain clothing

Question 29

Relapse

Answer 29

- Same organism within 2 weeks after completion - Obtain sample and culture for susceptibility - Evaluate resistance, adherence, and other sources

Question 30

Recurrence

Answer 30

- >2 weeks after treatment or after documented sterile culture - Defined as >= 2 UTIs within 6 months or >= 3 UTIs in a year