Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

3151 Therapeutics > Urinary Tract Infection > Flashcards

Urinary Tract Infection Flashcards

1
Q

What is the difference between Asymptomatic Bacteriuria (ASB) and Urinary Tract Infection (UTI)?

A

ASB: isolation of significant colony counts of bacteria in the urine WITHOUT symptoms of UTI

UTI: isolation of significant colony counts of bacteria in the urine WITH symptoms of UTI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Asymptomatic Bacteriuria (ASB) is common

What are the only two populations that should be screened and treated for ASB?

Why?

A
  1. Pregnant women
  • To prevent pyelonephritis, preterm labor, and infant low birth weight
  • Screen at one of the first visits (12-16 weeks gestation)
  • If bacteriuria, treat with active antibiotics for 4-7 days
  1. Patients going for urologic procedure in which mucosal trauma/bleeding is expected
  • Prevent bacteremia and urosepsis
  • Screen 2-3 days prior to procedure
  • If bacteriuria, treat with active antibiotics as surgical antibiotic prophylaxis (SAP)
  • *this does not include placement of a urinary catheter
  • *E.g., TURP (trans urethral resection of prostate, cystoscopy with biopsy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Asymptomatic Bacteriuria (ASB) is common

List patient populations who should NOT be screened or treated for ASB. (Since treatment of ASB did not decrease the risk for subsequent UTI)

A

Children
Healthy women
Persons with diabetes
Elderly >= 70yo
Elderly in long-term care facility
Persons with spinal cord injury - catheter use
Persons with kidney transplant
Persons with indwelling catheter use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is non-treatment of ASB important?
(*except in the two adult populations)

A

Important opportunity to decrease inappropriate antibiotic use
(in line with antimicrobial stewardship programs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Should patients with ASB + delirium, but without UTI symptoms, be treated with antibiotics?

A

No

  • No evidence that delirium is a symptom of UTI in the absence of urinary symptoms
  • ASB is not associated with delirium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Should patients with signs of systemic infection + delirium, but without UTI symptoms, be treated with antibiotics?

A

Yes

If signs of systemic infection are present, then we may start empiric antibiotics regardless of presence of UTI symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe how the prevalence of UTI varies with age and gender

A

0-6months: males > females

  • higher rate of structure and functional abnormalities of the urinary tract in boys

1-adult: females > males

  • urethra is shorter, bacteria access bladder more easily
  • prostate secretes antibacterial substances that confer additional protection

elderly >65yo: males = females

  • prevalence is related to comorbidities (BPH, bowel incontinence, use of catheter)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the two routes of infection (pathogenesis) of UTI

A
  1. Ascending
  • Colonic/fecal flora colonize the periurethra area/urethra and ascend to bladder and kidney (*in normal circumstance, urine in kidney and bladder should be sterile!)
  • Higher risk in females due to shorter urethra, use of spermicides or diaphragms
  • Enteric gram negative rods (enterobacteriaceae - E. coli, Klebsiella, Proteus) (*recall these are oxidase negative, lactose/non-lactose fermenting)
  1. Descending/Hematogenous
  • Organism at distant primary site => bloodsteam (bacteremia) => urinary tract => UTI
  • E.g., Staph Aureus, Mycobacterium tuberculosis
  • Impt to check if pt has bacteremia and any primary site of infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some host defense mechanisms against the development of UTI?

A
  • Bacteria in bladder stimulations micturition with increased diuresis
  • Antibacterial properties of urine and prostatic secretion
  • Anti-adherence mechanisms of the bladder mucosa (enzymes that prevent bacterial attachment to the bladder mucosa)
  • Inflammatory response with polymorphonuclear leukocytes/neutrophils (PMNs), phagocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does size of the inoculum affect development of UTI?

A

As inoculum size increases (higher load of pathogens), increase risk of UTI

Inoculum size may increase due to urinary retention/obstruction (bacteria continue to multiply in bacteria and urinary tract without being passed out)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the virulence/pathogenicity of the microorganism affect the development of UTI?

A

Likelihood to cause disease
- E.g., bacteria with pili (e.g., E. coli) is resistant to washout or removal by anti-adherence mechanism of the bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some risk factors for UTI?

A
  1. Females > Males (shorter urethra)
  2. Sexual intercourse (vaginal to urethra area)
  3. Abnormalities of the urinary tract (e.g., prostatic hypertrophy, kidney stones, urethral strictures => all cause urinary obstruction, vesicoureteral reflux)
  4. Neurologic dysfunction (e.g., stroke, diabetes, spinal cord injury => urinary retention)
  5. Anti-cholinergic (SE: urinary retention)
  6. Catheterization (e.g., biofilms)
  7. Diabetes (neurologic dysfunction + sugar content in urine promote bacterial growth)
  8. Pregnancy
  9. Use of diaphragms and spermicides (alter flora, incr colonization of periurethrea and vaginal area)
  10. Genetic association (positive family history)
  11. Previous UTI (unresolved risk factors?)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are some non-pharmacological advice for prevention of UTI?

A
  1. Drink lots of fluid to flush out bacteria (6-8 glasses a day)
    *Caution if fluid restricted - CKD, HF
  2. Urinate frequently, go when feel urge
  3. Urinate shortly after sex
  4. Wipe from front to back
  5. Wear cotton underwear and loose-fitting clothes (keep area dry)
    *Avoid tight fitting jeans and nylon underwear which trap moisture
  6. Consider alternative birth control methods
    *Do not use spermicides, diaphragms, unlubricated condoms, spermicidal condoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the classification of complicated vs uncomplicated UTI

A

Uncomplicated:

  • Healthy, premenopausal, non-pregnant women with no history of abnormal urinary tract
  • Urinalysis and urine culture not routinely needed for uncomplicated cystitis, but needed for pyelonephritis

Complicated:

  • UTI associated with conditions that increase the potential for serious outcomes, risk for therapy failure, recurrence of UTI
  • Men, children, pregnant women
  • Presence of complicating factors: abnormalities of urinary tract, genitourinary instrumentation, diabetes mellitus, immunocompromised host
  • Urinalysis and culture indicated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. Confirm presence of infection

What are the subjective symptoms for lower UTI (cystitis) and upper UTI (pyelonephritis) respectively?

A

Cystitis:

  • Dysuria, urgency, frequency, nocturia, suprapubic heaviness or pain, gross hematuria (blood in urine)

Pyelonephritis: (more systemic signs)

  • Fever, rigors, headache, nausea and vomiting, malaise
  • Flank pain, costovertebral tenderness (renal punch), abdominal pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. Confirm presence of infection

What are the objective symptoms for UTI?

A

VITAL SIGNS AND LABS

  • Temp >=38, HR >90, RR >22, BP <100, mental status
  • TW (4-10 x 10^9 /L), neutrophils (45-75%), CRP (>40mg/L), PCT (cut off <0.25ug/L)

URINALYSIS

  • Microscopic urinalysis (UFEME) lab

=> WBC >10 WBCs/mm^3 = pyuria [pus in urine]
=> RBC >5 / HPF or gross = hematuria [blood in urine]
=> Microorganisms - gram stain
=> WBC casts - masses of cells and proteins that form in renal tubules (indicates upper tract infection, kidney involvement)
*If squamous epithelial cells seen, likely suggest contamination of urine sample

  • Chemical urinalysis, no lab

=> Nitrite - positive tests detects presence of gram-negative bacteria (*requires at least 10^5 bacteria/ml)
=> Leukocyte esterase (LE) - positive test detects esterase activity of leukocytes in the urine, correlates with significant pyuria (>10 WBCs/mm^3)

CULTURE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  1. Confirm presence of infection

What are the 3 methods of urine collection?

A
  1. Midstream clean-catch (discard 1st 20-30ml that may be contaminated with urethra colonizers)
  2. Catheterization
  3. Suprapubic bladder aspiration (needle to bladder)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  1. Confirm presence of infection

What could cause false negative in a nitrite dipstick test?

A
  • presence of gram-positive organisms and P. aeruginosa
  • low urinary pH
  • frequent voiding
  • dilute urine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
  1. Confirm presence of infection

In what cases could absence of pyuria still suggest UTI?

A
  • Diluted urine
  • Patient has neutropenia (pt alr lack WBC)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
  1. Confirm presence of infection

When should urine cultures be obtained?

A

Pre-treatment cultures needed for:

  • pregnant (complicated)
  • recurrent UTI (within 2 weeks)
  • pyelonephritis
  • catheter-associated UTI
  • men with UTI (complicated)

NOT required for:
- uncomplicated cystitis (urinary symptoms + urinalysis dipstick positive sufficient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  1. Identification of likely pathogen for UTI

Name the likely pathogens for uncomplicated or community-acquired UTI

A

E. Coli (>85%)

Staphylococcus saprophyticus (5-15%) - common colonizer of urinary tract

Others: (associated with gut enterobacteriaceae)
- Enterococcus faecalis
- Klebsiella pneumoniae
- Proteus spp

22
Q
  1. Identification of likely pathogen for UTI

Name the likely pathogen for complicated or healthcare-associated UTI

A

*Typically more resistant strains (e.g., ESBL producing E coli/proteus/klebsiella)

E. Coli (50%)

Enterococci

Proteus, Klebsiella, Enterobacter

Pseudomonas Aeruginosa (HAI)

23
Q
  1. Identification of likely pathogen for UTI

What are healthcare associated risk factors (likely for P. aeruginosa)

A

Recent and/or frequent exposure to healthcare settings:

  • Hospitalization in the last 90 days
  • Current hospitalization >= 2 days
  • Residence in nursing home
  • Recent antimicrobial use
24
Q
  1. Identification of likely pathogen for UTI

What do S. aureus and yeast/candida suggest in UTI?

A

S. aureus
- possible bactermia, assess primary site of infection

Yeast/candida
- common contaminant (from colon, bowel)
- assess other sites of infection if want to treat

25
Q
  1. Selection of antimicrobial and regimen

What are some considerations when treating uncomplicated community-acquired infections?

A
  • Do not use broad spectrum (e.g., Pip-Tazo) to prevent selection pressure and resistant
  • Based on antibiogram ~70% susceptibility is sufficient (do not select those with 100% susceptibility)
26
Q
  1. Selection of antimicrobial and regimen

What are the firstline treatment options for empiric antibiotics for cystitis in women?
*Culture need not be taken

A

First line:
- PO co-trimoxazole 800/160 mg BID x3d
- PO nitrofurantoin 50mg qid x5d
- PO fosfomycin 3g single dose sachet

27
Q
  1. Selection of antimicrobial and regimen

What are the beta-lactam alternative treatment options for empiric antibiotics for cystitis in women?
*Culture need not be taken

A

(PO Beta lactams x5-7d)
- Cefuroxime 250mg BID
- Amoxicillin-clavulanate 625mg BID
- Cephalexin 250-500mg qid (however, due to low susceptibility seen in community antibiogram, consider use in 1st timer unlikely to have resistance)

28
Q
  1. Selection of antimicrobial and regimen

What are the Fluoroquinolone alternative treatment options for empiric antibiotics for cystitis in women?
*Culture need not be taken

A

(PO fluroquinolones x3d) - generally not used in uncomplicated cystitis, reserve for HAI with pseudomonas
- Ciprofloxacin 250mg BID
- Levofloxacin 250mg daily

29
Q
  1. Selection of antimicrobial and regimen

What if it is complicated cystitis in women?

A
  • Longer duration (e.g., 7 to 14 days)
  • Fosfomycin dose for complicated cystitis is PO 3g EOD x3 doses
30
Q
  1. Selection of antimicrobial and regimen

Why is fosfomycin not recommended for use as empiric treatment in hospitals for cystitis?

A

Fosfomycin generally reserved for ESBL-producing E. Coli

31
Q
  1. Selection of antimicrobial and regimen

Which antibiotics can only be used in cystitis as they are unable to reach kidney tissues?

A

Fosfomycin, Nitrofurantoin

32
Q
  1. Selection of antimicrobial and regimen

What are the firstline treatment options for empiric antibiotics for community-acquired pyelonephritis in women?

*Culture should be taken, therapy modified when urine culture susceptibility available

A

First line:

(PO fluroquinolones) => bc of shortest treatment duration
- Ciprofloxacin 500mg BID x7d
- Levofloxacin 750mg daily x5d

33
Q
  1. Selection of antimicrobial and regimen

What are the alternative treatment options for empiric antibiotics for community-acquired pyelonephritis in women?

*Culture should be taken, therapy modified when urine culture susceptibility available

A

PO co-trimoxazole 800/160mg BID x10-14d

(PO beta-lactam x10-14d)
- Cefuroxime 250-500mg bid
- Amoxicillin-clavulanate 625mg tds or 1g bid
- Cephalexin 500mg qid (concern of low susceptibility)

34
Q
  1. Selection of antimicrobial and regimen

What are the treatment options for empiric antibiotics for community-acquired pyelonephritis in women (and pt is severely ill, requiring hospitalization / unable to take oral drugs)?

A

IV therapy for pyelonephritis:

  • IV Ciprofloxacin 400mg bid
  • IV Cefazolin 1g q8h
  • IV Amoxicillin-clavulanate 1.2g q8h

*May add Gentamicin 5mg/kg to cover low % of ESBL producing strains in the community

*Switch to oral when pt improved

35
Q
  1. Selection of antimicrobial and regimen

What are the treatment options for empiric antibiotics for cystitis in men (with NO concern for prostatitis)?

*Culture should be taken, therapy modified when urine culture susceptibility available

A

Cystitis with no concern for prostatitis:
- Follow regimen for complicated cystitis in women (first line co-trimoxazole/nitrofurantoin/fosfomycin for longer duration of 7-14 days)

36
Q
  1. Selection of antimicrobial and regimen

What are the treatment options for empiric antibiotics for cystitis in men (WITH concern for prostatitis or pyelonephritis)?

*Culture should be taken, therapy modified when urine culture susceptibility available

A

Cystitis with concern for prostatitis OR Pyelonephritis:
- PO Ciprofloxacin 500mg BID
- PO Co-trimoxazole 800/160mg BID

*Treat for 10-14 days, longer duration 4-6 weeks if prostatitis confirmed (prostatitis: more acutely ill, pain in pelvic area)
*Recall trimethoprim and fluroquinolones concentrate well in the prostate

37
Q
  1. Selection of antimicrobial and regimen

What are the treatment options for empiric antibiotics for nosocomial/healthcare-associated pyelonephritis? (more sick, require IV)

*Culture should be taken, therapy modified when urine culture susceptibility available

A

Consider possibility of Pseudomonas aeruginosa and ESBL producing E coli and Klebsiella

Choices:
- IV Cefepime 2g q12h +/- IV amikacin 15mg/kg/d (aminoglycoside add ESBL cover)
- IV Imipenem 500mg q6h
- IV Meropenem 1g q8h

*Duration of treatment: 7-14 days

38
Q
  1. Selection of antimicrobial and regimen

What are the treatment options for empiric antibiotics for nosocomial/healthcare-associated pyelonephritis? (less sick)

*Culture should be taken, therapy modified when urine culture susceptibility available

A

Consider possibility of Pseudomonas aeruginosa and ESBL producing E coli and Klebsiella

If pt is less sick:
- PO Levofloxacin 750mg daily
- PO Ciprofloxacin 500mg BD

*Duration of treatment: 7-14 days

39
Q

What is classified as nosocomial/healthcare associated pyelonephritis?

A

Nosocomial:
- onset of UTI >48h post admission

Healthcare-associated:
- hospitalized or underwent invasive urological procedures in the last 6 months
- has an indwelling catheter

40
Q

What is the definition of catheter-associated UTI?

A

symptoms or signs compatible with UTI with no other identified source of infection, along with 10^3 cfu/mL of >=1 bacterial species in a single catheter urine specimen, in patients with indwelling urethral, indwelling suprapubic, or intermittent catheterization, or in a midstream voided urine specimen from a patient whose catheter has been removed within the previous 48h

41
Q

When should a positive urine culture be treated as catheter-associated UTI?

*NOTE if aymptomatic, it should not be treated

A
  • urinary symptom present

OR

  • signs and symptoms of infection present, with no other cause of infection

*catheter-associated UTI is low risk and rarely results in symptomatic manifestation, hence impt to exclude other causes of infection before treating positive urine culture
*if fever is low grade and pt is stable, may consider observation rather than immediate antibiotics therapy

42
Q

What are the risk factors for the development of catheter-associated UTI?

A
  • Duration of catheterisation (colonization)
  • Colonization of drainage bag, catheter, and periurethral segment
  • DM (glucose in urine)
  • Female
  • Renal function impairment
  • Poor quality of catheter care, including insertion (*urine culture should be taken from a new catheter)
43
Q

What organisms cause catheter-associated UTI?

A

Short term catheterization (<7d): 85% single organism
Long term catheterization (>28d): 95% polymicrobial (2-3 organisms)

44
Q
  1. Selection of antimicrobial and regimen

What are the non-antibiotics treatment options for catheter-associated UTI?

*Culture should be taken, therapy modified when urine culture susceptibility available

A
  • Removal of catheter
  • If catheter has been placed for >2 weeks at the onset of CA-UTI and is still indicated, then replace catheter to hasten resolution of symptoms + reduce risk of subsequent CA-bacteriuria and CA-UTI
45
Q
  1. Selection of antimicrobial and regimen

What are the treatment options for empiric antibiotics for catheter-associated UTI?

*Culture should be taken, therapy modified when urine culture susceptibility available

A

*Similar to nosocomial pyelonephritis

Empiric options:

  • IV imipenem 500mg q6h
  • IV meropenem 1g q8h
  • IV Cefepime 2g q12h +/- IV amikacin 15mg/kg/d (1 dose)
  • PO/IV levofloxacin 750mg x5d
  • PO co-trimoxazole 800/160mg bid x3d (for women =<65yo with CA-UTI without upper urinary tract symptoms after an indwelling catheter has been removed)

Duration:

  • 7 days for those with prompt resolution of symptoms (defervesce in 72h)
  • 10-14 days for those with delayed response

*May also use PO Fosfomycin 3g EOD x3 doses

46
Q

How can catheter-associated UTI be prevented?

A
  • Avoid unnecessary catheter use
  • Minimize duration of catheter use (*trial off catheter)
  • Long-term indwelling catheters changed before blockage
  • Use of closed system
  • Aseptic insertion technique
  • Topical antiseptic or antibiotics NOT recommended
  • Prophylactic antibiotics NOT recommended
  • Chronic suppressive antibiotics NOT recommended (selection pressure, only treat w each episode)
47
Q

What antibiotics choices can be used for UTI in pregnancy?

A

*Choices as per complicated UTI in non-pregnant women

AVOID:

  • Ciprofloxacin (fetal cartilage damage, arthropathy)
  • Co-trimoxazole (1st and 3rd trimester - folic acid deficiency, G6PD risk, kernicterus)
  • Nitrofurantoin (38-42 weeks - G6PD)
  • Aminoglycosides (8th cranial nerve toxicity in fetus)

MAY USE: *use complicated UTI regimen

  • Co-trimoxazole (2nd trimester)
  • Nitrofurantoin (before 38 weeks)
  • Fosfomycin - 3g, EOD x3 doses
  • Beta-lactams

Duration of treatment:

  • ASB or Cystitis: 4-7 days
  • Pyelonephritis: 14 days
48
Q

What are some adjunctive therapy for UTI?

  • For pain and fever
  • For vomiting
  • For urinary symptoms
A

Pain and fever - paracetamol, NSAIDs

Vomiting - rehydration

Urinary symptoms:

Phenazopyridine - Topical analgesic effect on urinary tract mucosa, relief dysuria symptoms

Urine alkalization - relief discomfort in mild UTI

Cranberry juice - inhibit adherence of E coli to urinary tract epithelial cells

Intravaginal estrogen cream - restore vaginal flora, prevent E coli colonization

Lactobacillus probiotics - restore vaginal flora, prevent E coli colonization

49
Q

What is the dose of Phenazopyridine used?
What is the treatment duration?
What are its ADRs?
Which group of patient should NOT use Phenazopyridine?

A

Phenazopyridine 100-200mg TDS

  • Treatment limited to duration of symptoms
  • ADR: nausea, vomiting, orange-red discolouration of urine and stool
  • Do NOT use in G6PD deficiency
50
Q
  1. Monitor response
    - Therapeutic response (how long for symptom improvement/resolution, is bacteria clearance culture required?)
    - Adverse drug reactions
A

Resolution of signs and symptoms

  • improvement or resolution by 24-72h after initiation of effective Abx
  • if pt fails to respond clinically within 2-3 days or has persistently positive blood or urine cultures, further investigation is needed to exclude bacterial resistance, possible obstruction, renal abscess, or some other disease process

Bacteriological clearance

  • repeat culture NOT required for pt who responded
  • culture required to document clearance of infection for PREGNANT WOMEN

Absence of ADRs and allergies - ensure no rash, itch, swollen eyes

3151 Therapeutics (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions