UTI Flashcards

1
Q

What is Asymptomatic Bacteriuria(ASB)?

A

isolation of significant colony counts of bacteria in the urine(bacteriuria) from a person WITHOUT symptoms of UTI

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2
Q

Screening and treatment of ASB is only indicated for ______ populations

A

1) Pregnant women [2-7%]

2) Patients going for urological procedure in which mucosal trauma/bleeding is expected [eg. TURP, cystoscopy with biopsy]

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3
Q

When and Why do pregnant women screen and treat ASB?

A

To prevent pyelonephritis, preterm labor and infant low birth weight

Screen at one of the first visits(12-16 weeks gestation)
- Do urine culture
- If bacteriuria, treat with active antibiotics(based on AST) for 4-7 days

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4
Q

When and Why do screen and treat ASB?

A

To prevent postoperative bacteremia and urosepsis

Screen prior to procedure — 2-3 days before
- If bacteriuria, use active antibiotics as surgical antibiotic prophylaxis(SAP)(based on AST)
Does not include placement of a urinary catheter

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5
Q

Epidemiology of UTI

A

Increasing from young to old
* 0-6 mths: males > females
* 1-adult: females > males
* Elderly(age>65): equal

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6
Q

What are the 2 routes of infection of UTI

A
  1. Ascending [most common]
    * colonic/fecal flora colonise periurethral area/urethra → ascend to bladder & kidney
    * Gram-negative bacilli (E.coli/Klebsiella/Proteus)
  2. Hematogenous(descending)
    * Organism at distant primary site(heart/bone) → bloodstream(bacteremia) → urinary tract → UTI
    * S.aureus, TB
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7
Q

What are the factors determining the development of UTI?

A

1) Competency of the natural host defense mechanisms
- bacteria stimulate micturition(increase urge of emptying bladder)
- antibacterial properties of urine and prostate secretions
- anti-adherence mechanism of bladder(prevent bacteria attachment)
- Inflammatory response by leukocytes → phagocytosis

2) Size of the inoculums(load of bacteria that is present at the site of infection)

3) Virulence/pathogenicity of the microorganism

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8
Q

What are the risk factors of UTI?

A
  • Gender(Female > male)
  • Sexual intercourse
  • Abnormalities of the urinary tract (prostatic hypertrophy, kidney stones, urethral strictures, vesicoureteral reflux)
  • Neurological dysfunctions (stroke, DM, spinal cord injuries)
  • Anticholinergic drugs (SE: urinary retention)
  • Catheterization and other mechanical instrumentation
  • Diabetes
  • Pregnancy
  • Use of diaphragms & spermicides
  • Genetic association(positive family history)
  • Previous UTI
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9
Q

NPM of UTI

A

1) Drink lots of fluid to flush bacteria
2) Urinate frequently
3) Urinate shortly after sex
4) Wipe from front to back
5) Wear cotton underwear and loose-fitting clothes so that air can keep the area dry
6) Those on diaphragm/spermicide as birth control: consider modifying your birth control method
* Unlubricated condoms or spermicidal condoms increase irritation(grow bacteria)

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10
Q

What are considered complicated UTI?

A
  • UTI in men, children and pregnant women
  • Presence of complicating factors:
    1) Functional/structural abnormalities or urinary tract
    2) genitourinary instrumentation
    3) DM
    4) immunocompromised host
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11
Q

Symptoms of cystitis(LUTI)

A
  • Dysuria(pain on urination)
  • Urgency
  • Frequency
  • Nocturia
  • Suprapubic heaviness or pain
  • Gross hematuria
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12
Q

Symptoms of pyelonephritis(UUTI)

A
  • Fever, malaise
  • Rigors
  • Headache
  • Nausea and vomiting
  • Flank pain
  • Costovertebral tenderness(renal punch)
  • Abdominal pain
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13
Q

Microscopic urinalysis(UFEME: urine formed elements and microscopic examination) tests for?

A

White blood cells(WBC)
* >10 WBCs/mm3 = pyuria
* Signifies presence of inflammation(may or may not be due to infection. If symptomatic, pyuria correlates with significant bacteriuria
* Absence of pyuria = unlikely UTI

Red blood cells(RBC)
* Presence(microscopic >5/HPF or gross) = hematuria
* Frequently occurs in UTI but non-specific

Microorganisms
* Identify bacteria or yeast using gram-stain

WBC casts
* Masses of cells and proteins that form in renal tubules(kidneys)
* Indicates upper tract infection/disease

if there is presence of squamous epithelial, urine might have been contaminated

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14
Q

What are the 2 Chemical urinalysis(dipstick) tests?
What do they test for?

A

1. Nitrate
- Positive test detects presence of gram-negative bacteria
- Only gram negative bacteria reduces nitrate to nitrite
- Requires at least 10^5 bacteria/ml
- False-negative results due to presence of gram-positive organisms and P.aeruginosa, low urinary pH, frequent voiding and dilute urine
2. Leukocyte esterase(LE)
- Positive tests detects esterase activity of leukocytes in urine
- Correlates with significant pyuria(>10 WBCs/mm3)

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15
Q

When is urine culture(pre-treatment culture) required?

A
  • Pregnant women
  • Recurrent UTI(relapse within 2 weeks or frequent)
  • Pyelonephritis
  • Catheter-associated UTI
  • All men with UTI

Not need for urine culture in uncomplicated cystitis

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16
Q

What are the likely pathogens for uncomplicated/community-acquired UTI?

A
  • Escherichia coli(>85%)
  • Staphylococcus saprophyticus(5-15%)
  • Enterococcus faecalis
  • Klebsiella pneumoniae
  • Proteus spp
17
Q

What are the likely pathogens for complicated/healthcare-associated UTI?

A
  • Escherichia coli(~50%)
  • Enterococci
  • Proteus spp
  • Klebsiella spp
  • Enterobacter spp
  • P.aeruginosa

HA risk factors: recent/frequent exposure to healthcare settings
(last 90 days, current>/=2days, nursing home)

18
Q

____ commonly causes UTI from bacteremia
____ causes UTI by acting as a possible contaminant

A

S.aureus
Yeast/Candida

19
Q

When do you treat UTI positive culture with antibiotics?
NO if ____
YES if ____

A
  • NO if patient does not have symptoms of UTI but positive culture(ASB) except for Pregnant women & patients going for urologic procedure in which mucosal trauma/bleeding is expected
  • YES if patients is symptomatic(urinary symptoms) or any of the 2 exceptions above
20
Q

What are the first line empiric abx for cystitis in women?

A
  • PO Co-trimoxazole 800/160 mg bid x 3d (2 tablets)
  • PO Nitrofurantoin 50mg qid x 5d
  • PO Fosfomycin 3g single dose

Alternatives:
- PO beta-lactams x 5-7 days
- PO cefuroxime 250 mg bid
- PO amoxicillin-clavulanate 635 mg bid
- PO cephalexin 250-500mg qid(rising resistance)
- PO fluroquinolones x 3 days
- PO ciprofloxacin 250 mg bid
- PO levofloxacin 250 ng daily
Collateral damage is high, ONLY oral for pseudo

21
Q

What are the first line empiric abx for Complicated Cystitis in women?

A
  • Same as uncomplicated cytitis in women BUT
  • Treat for longer duration (7-14 days)
  • Fosfomycin PO 3g EOD x 3 doses
22
Q

What are the first line empiric abx for Community-acquired pyelonephritis(kidney) in women?

A
  • PO fluoroquinolones
    - PO ciprofloxacin 500mg twice daily x 7 days
    - PO levofloxacin 750mg daily x 5 days
23
Q

What are the 2nd and 3rd line empiric abx for Community-acquired pyelonephritis(kidney) in women?

A

2nd line: PO co-trimoxazole 160/800mg twice daily x 10-14 days
3rd line: PO beta-lactam x 10-14 days
- PO cefuroxime 250-500 mg bid
- PO amoxicillin-clavulanate 625mg tds
- PO cephalexin 500mg qid

24
Q

What are the empiric abxs for Community-acquired pyelonephritis(kidney) in women?
that are severely ill;require hospitalization[AG not good if bacteremia]
OR
unable to take oral drugs

A
  • Initial intravenous(IV) therapy
    - IV ciprofloxacin 400mg bid
    - IV cefazolin 1g q8h
    - IV amoxi-clav 1.2g q8h
    **AND/OR **
  • IV/IM gentamicin 5mg/kg
    - To cover low % of ESBL ecoli/klebsiella in the community

Switch to oral when patient improved or able to take orally
- Initial empiric therapy should be modified when result of urine culture and susceptibility becomes available(->definitive/culture-directed therapy)

25
Q

What are the first line empiric abx for Community-acquired UTI in men?
More specifically:
1. For cystitis, NO concern for prostatitis
2. For cystitis + concern for prostatitis/pyelonephritis

A
  1. Same as women
    • Treat for longer duration (7-14 days)
    • Fosfomycin PO 3g EOD x 3 doses
    • PO ciprofloxacin 500mg twice daily
      • PO co-trimoxazole 160-800mg twice daily
      • Treat for 10-14 days, will need longer duration if prostatitis is confirmed(6 weeks)
26
Q

What defines Nosocomial/Healthcare-associated

A
  • Nosocomial - onset of UTI >48hr post admission
  • **Healthcare associated **- patients who have been hospitalized or underwent invasive urological procedures in the last 6 months, has an indwelling urine catheter
27
Q

What are the empiric abx for Nosocomial/Healthcare-associated pyelonephritis?

A

Possibility of Pseudomonas aeruginosa
and other resistant bacteria:

- Broad spectrum B-lactam may be used
- IV cefepime 2 g q12h +/- IV amikacin/gentamicin 15mg/kg/d
- IV imipenem 500mg q6h
- IV meropenem 1g q8h
duration of treatment: 7-14 days

Less sick patients(oral therapy)
- PO levofloxacin 750mg
- PO ciprofloxacin 500mg bid
duration of treatment: 7-14 days

28
Q

What is Catheter-associated UTI

A
  • most common cause of nosocomial UTI
  • Presence of 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 48 hours
29
Q

What are the risk factors for Catheter-associated UTI

A
  • Duration of catheterization
  • Colonization of drainage bag, catheter and periurethral segment
  • DM
  • Female
  • Renal function impairment
  • Poor quality of catheter care, including insertion
30
Q

How do you manage Catheter-associated UTI?

A
  • Consider removal of catheter
  • Abx only for symptomatic infection
  • If stable and fever is low grade, observation rather than immediate Abx therapy
  • Urine(+/- blood) culture must be taken before antibiotics is given
31
Q

Abx treatment for Catheter-associated UTI

A

Abx:
- IV imipenem 500mg q6h
- IV meropenem 1g q8h
- IV cefepime 2g q12h +/- IV amikacin 15mg/kg(1 dose)
- PO/IV levofloxacin 750mg x 5d (for mild CA-UTI)
- PO co-trimoxazole 960mg bid x 3d
- for women = 65 years with CA-UTI without upper urinary tract symptoms after an indwelling catheter has been removed

Duration:
- Prompt resolution of symptoms: 7 days
- Delayed responses: 10-14 days
- Chronic suppressive therapy is not recommended
- Do not give prophylaxis long term, only give if patient has deadly infection

32
Q

Prevention of Catheter-associated UTI

A
  • Avoid unnecessary catheter use
  • Use for minimal duration
  • Long-term indwelling catheters changed before blockage is likely to occur
  • Use of closed system
  • Ensure aseptic insertion technique
  • Topical antiseptic or antibiotics not recommended
  • Prophylactic antibiotics and antiseptic not recommended
  • Chronic suppressive antibiotics is not recommended
33
Q

What Abx to avoid for UTI tx in pregnant women?

A
  • Avoid ciprofloxacin
  • Avoid co-trimoxazole in 1st and 3rd trimester
  • Nitrofurantoin avoided at term(38-42 weeks)
  • Aminoglycosides are used with caution
34
Q

Treatment of UTI in pregnant women

A
  • Beta-lactams are safe options in pregnancy(1st line in pregnant UTI)
    - Treat for 4-7 days for ASB/cystitis
    - Treat for 14 days for pyelonephritis
35
Q

Adjunctive therapy for UTI

A
  • Pain and fever - Paracetamol, NSAIDs
  • Vomiting - Rehydration
  • Urinary symptoms - Phenazopyridine(Urogesic®), Urine alkalization

100-200mg tds, Do not use if G6PD
N/V,orange-red discoloration of urine

36
Q

What to monitor for UTI?

A
  • Resolution of signs & symptoms
    - Improvement or resolution by 24 to 72 hrs after initiation of effective antibiotics
    - If pt fails to respond clinically within 2-3 days or has persistently positive blood/urine cultures, further investigation is needed to exclude bacterial resistance, possible obstruction, renal abscess, or some other disease process
  • Bacteriological clearance
    - Repeat culture is not required for patients who responded
  • Absence of adverse drug reactions and allergies