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Flashcards in UTI Deck (43)
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1
Q

Asymptomatic bacteriuria

A

self-limiting

UTI will go away w/o treatment

2
Q

Classification of UTI anatomy

A

Anatomy

Upper UTI
- pyelonephritis (kidney)

Lower UTI

  • Cystitis (bladder)
  • Urethritis (urethra)
  • Prostatitis (prostate)
  • Epididymitis (epididymis)

Catheter-associated UTI

3
Q

Epidermiology

A

0-6mths M>F
1-adults F>M
>65 equal

4
Q

Pathogenesis route of infection

A

1) ascending (most common)
•Colonic/ fecal flora colonise periurethra area/ urethra
–> ascend to bladder & kidney

  • Higher risk in females (shorter urethra), use of spermicides, diaphragms as contraceptives
  • Eg of organisms –E. coli, Klebsiella, Proteus

2) Hematogenous (Descending)
•Organism at distant primary site (eg heart valve, bone) –> bloodstream (bacteremia) –>urinary tract –>UTI
•Eg of organisms –Staphylococcus aureus, Mycobacterium tuberculosis
(NEED TO SCAN PT for bacteremia or any pri site of infection)

5
Q

Organisms for ascending uti

A

Eg of organisms –E. coli, Klebsiella, Proteus

6
Q

Risk of ascending UTI

A

Higher risk in females (shorter urethra), use of spermicides, diaphragms as contraceptives

7
Q

Organisms for descending UTI

A

•Eg of organisms –Staphylococcus aureus, Mycobacterium tuberculosis

8
Q

Factors determining the development of UTI

A

Competency of natural host defense mechanism
size of inoculum
virulence/pathogenicity of microorganism

•Host Defense Mechanisms

  • Bacteria in bladder stimulates micturition with increased diuresis –> emptying of bladder
  • Antibacteria properties of urine & prostatic secretion
  • Anti-adherence mechanisms of bladder (prevent bacterial attachment to the bladder)
  • Inflammatory response with polymorphonuclear leukocytes (PMNs) –> phagocytosis –> prevent/ control spread

•Size of the inoculum
- incr with obstruction/ urinary retention

•Virulence/ pathogenicity of the microorganism
- eg bacteria with pili (eg E. coli) resistant to washout or removal by anti-adherence mechanisms of bladder

9
Q

Risk factor for UTI

A

•Sexual intercourse
•Genetic association (positive family history)
•Catheterization and other mechanical instrumentation
•Previous UTI
•Abnormalities of the urinary tract eg prostatic
•Pregnancy
•Anti-cholinergic drugs
hypertrophy, kidney stones, urethral strictures,
vesicoureteral reflux
•Females > males
•Use of diaphragms & spermicides
•Neurologic dysfunctions eg stroke, diabetes, spinal
cord injuries
•Diabetes

10
Q

How to prevent UTI

A
  • Drink LOTS OF FLUID to flush the bacteria. Go for 6-8 glasses a day. But do not drink this much fluid if cannot drink this amount due to other health problems.
  • URINATE FREQUENTLY and go when you first feel the urge. Bacteria can grow when urine stays in the bladder too long.
  • Urinate SHORTLY AFTER SEX. This can flush away bacteria that might have entered your urethra during sex.
  • After using the toilet, always wipe from FRONT TO BACK , especially after a bowel movement
  • Wear cotton underwear and loose-fitting clothes so that air can keep the area dry.
  • Avoid tight-fitting jeans and nylon underwear, which trap moisture and can help bacteria grow.
  • For women, using a diaphragm or spermicide for birth control can lead to UTIs by increasing bacteria growth. If you have trouble with UTIs, consider modifying your birth control method. Unlubricated condoms or spermicidal condoms increase irritation, which may help bacteria grow.
11
Q

Classification of UTI seriousness

A

•Complicated:
UTI associated with conditions that increase the potential for SERIOUS OUTCOME, risk for THERAPY FAILURE OR RECURRENCE
•Eg UTIs in men, children and pregnant women •Presence of complicating factors: functional and structural abnormalities of urinary tract, genitourinary instrumentation, diabetes mellitus, immunocompromised host

  • Uncomplicated: none of the above
  • Usually in healthy premenopausal, nonpregnant women with no history suggestive of an abnormal urinary tract
12
Q

clincial Spectrum for uncomplicated UTI

A

mild cystitis to severe pyelonephritis

13
Q

clincial Spectrum for complicated UTI

A

mild cystitis to life threatening urosepsis

14
Q

Diagnosis for uncomplicated UTI

A

Urinalysis and urine culture not routinely needed for suspected cystitis but recommended for pyelonephritis

15
Q

Diagnosis for complicated UTI

A

Urinalysis and urine culture indicated

16
Q

Diagnosis Subjective evidence

A

•lower urinary tract infections (CYSTITIS)
- dysuria, urgency, frequency, nocturia, suprapubic
heaviness or pain; gross hematuria

•upper urinary tract infections (PYELONEPHRITIS)
- fever, rigors, headache, nausea, vomiting, and
malaise, flank pain, costovertebral tenderness
(renal punch), or abdominal pain

17
Q

Urine collection methods

A

3 methods

1) midstream clean-catch
2) catheterization
3) suprapubic bladder aspiration

18
Q
Microscopic urinalysis (UFEME = urine form elements and microscopic examination) 
OBJECTIVE
A

1) White blood cells (WBC)
• > 10 WBCs/mm3= pyuria
•Signifies presence of inflammation, may or may not be due to infection.
•In a symptomatic patient, pyuria correlates with significant bacteriuria
•Absence of pyuria = UNLIKELY UTI

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

3) Microorganisms
•Identify bacteria or yeast using Gram-stain

4) WBC casts
•masses of cells and proteins that form in renal tubules (in kidneys)
•indicate upper tract infection / disease

19
Q

Chemical urinalysis (objective) dipstick

A

•Nitrite
 Positive test detects presence of Gram-negative bacteria
Requires at least 10^5 bacteria/ml
Only Gram-negative organisms reduces nitrate to nitrite

False-negative results due to presence of Gram-positive organsims and P. aeruginosa, low urinary pH, frequent voiding and dilute urine.

•Leukocyte esterase (LE) —produce by leucocyte and neutrophil
Positive test detects esterase activity of leukocytes in urine
Correlates with significant pyuria (>10 WBCs/mm3)

20
Q

Not necessary for urine culture

A

uncomplicated cystitis

21
Q

pre-treatment culture may be necessary for

A
  • Pregnant women
  • Recurrent UTI (relapse within 2 weeks or frequent) •Pyelonephritis
  • Catheter-associated UTI
  • All men with UTI
22
Q

Likely pathogen for uncomplicated or CA UTI

A

-Escherichia coli(>85%)
-Staphylococcus saprophyticus(5-15%)
-Others:
Enterococcus faecalis
Klebsiella pneumoniae
Proteus spp
(bottom 3 = ascending route)

23
Q

Likely pathogen for complicated or HA UTI

A

-E. coli (~50%)
-Enterococci (gram +)
-Proteus spp, Klebsiella spp, Enterobacter spp,
P.aeruginosa
-ESBL

24
Q

Health care associated risk factor

A

Healthcare-associated risk factors include:

1) Hospitalization in the last 90 days
2) Current hospitalization ≥ 2 days
3) Residence in nursing home
4) Antimicrobial use in the last 90 days
5) Home infusion therapy
6) Chronic dialysis

25
Q

Other likely pathogen HA/CA

A

•Miscellaneous:
-S. aureus–commonly due to bacteremia; consider other primary site of infections

-Yeast or Candida–possible contaminant; consider other sites of infection

26
Q

Positive urine culture tx or not

A

YES if patient is symptomatic (urinary symptoms)

NO if patient does not have symptoms of UTI (i.e. asymptomatic bacteriuria), except for:

1) Preschool Children (esp < 5 years old)
Treat based on culture & sensitivity

2) Pregnant women

3) Patients going for invasive urologic procedures eg TURP, cystoscopy with biopsy
Antibiotics given as prophylaxis.
Obtain culture then start antibiotics based on culture & sensitivity 12-24 hrs before procedure, continue until urine catheter is out.

27
Q

Goal & Monitoring Therapeutic Response

A

1)Resolution of signs & symptoms
Improvement or resolution by 24 to 72 hrs after initiation of effective antibiotics
If the patient fails to respond clinically within 2 to 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

2)Bacteriological clearance
Repeat culture is not required for patients who responded
Culture to document clearance of infection for •Pregnant women

3)Absence of adverse drug reactions and allergies

28
Q

Resurrent infections (cystitis)

A

•20% of recurrent cystitis are relapses: persistence of infections with the same organism (usually within 2 weeks)
- Indicates that patient may have kidney
involvement, renal abscess, structural
abnormality or resistant strains
- Urine culture should be performed
- Treat with prolonged duration of antibiotics 2-6
weeks (NO longer uncomplicated)

•80% are reinfections–after 2 weeks of index UTI episode, infection with a different organism/strain

    - Urine culture should be performed 
    - Treat as per separate episodes

The goal of long-term management of recurrent cystitis should be to improve the quality of life while minimizing antimicrobial exposure

29
Q

Management of recurrent cystitis

A
  1. Infrequent recurrence (< 3 infections per year)
    •treat each episode as a separate infection (but as complicated UTI)
  2. Frequent recurrence
    (> 2 infections per 6 months, or ≥ 3 infections per year)
    -need to evaluate reason(s) for recurrence eg structural or neurogenic abnormalities etc
    2.1 Prophylaxis
    Treat underlying infection before starting
    long-term prophylaxis
    Decrease occurrence by 95% while on
    prophylaxis
    Usually give 3-12 months, then reassess
    Drug regimens
    2.2 Post-coital prophylaxis (Single dose after
    sexual intercourse )
    2.3 Intermittent self-treatment
    Patient starts course of therapy with onset of typical signs and symptoms of cystitis.
    Useful for women with infrequent recurrences or who are concerned that they may develop infection while traveling or otherwise unable to access health care. Regimen as per acute cystitis.
30
Q

Non-antimicrobial option for prevention

A

1) Cranberry juice (cranberry proanthocyanidine)
–promising but need more reliable evidence
•inhibits adherence of E. coli to urinary tract epithelial cells
•clinical data suggestive of efficacy in decreasing incidence of UTI
•many limitations to existing studies

2) Intravaginal estrogen cream
-remains controversial
•decrease incidence of UTI’s in postmenopausal women
•restores vaginal flora, prevents colonization with E. coli

3) Lactobacillus probiotics
–promising but need more reliable evidence
•restore normal vaginal flora and have a protective effect against E. coli colonization
•recent small controlled trial showed intravaginal lactobacillus reduced recurrence uncomplicated cystitis

31
Q

UTI in pregnancy why have risk

A

Anatomic, hormonal and physiologic changes to urinary tract predispose to UTI

  1. Increased smooth muscle relaxation
  2. Dilatation of renal pelvis and ureters
    (THESE increase ASCEND to bladder and kidnery)
  3. Increase in bladder capacity
  4. Decreased ureteral peristalsis
  5. Partial obstruction of ureters due to enlarging uterus
    (INCREASE retention)

6.Pregnancy-associated glucosuria and aminoaciduria provide good growth medium for bacteria

Urinary tract returns to normal by approximately 2 months postpartum

32
Q

significance of bacteriuria in pregnancy

A
  • More likely to develop symptomatic UTI later in the pregnancy
  • Postpartum UTI more common in women with bacteriuria during pregnancy
  • Untreated –> development of PYELONEPHRITIS in 20 –50% of cases
  • Untreated –> increases risk of PRETERM DELIVERY, LOW BIRTH WEIGHT, infant and perinatal MORTALITY.
33
Q

UTI in pregnancy what should we do (not tx)

A

Screening for asymptomatic bacteriuria

  • Obtain urine culture at 12-16 weeks gestation or first prenatal visit
  • Negative culture –screen again at 3rd trimester •Positive culture (asymptomatic bacteriuria or symptomatic) –must treat; monitor for bacteriuria at every antenatal (monthly) visit until delivery
34
Q

Antibiotic choices for UTI in pregnancy

A

•Choices as per UTI in non-pregnant women or according to culture and susceptibility results;

EXCEPT:
1) Avoid ciprofloxacin
•Reports of fetal cartilage damage and arthropathies in animal studies and occasional human case reports in children; not confirmed in humans

2) Avoid co-trimoxazole in
FIRST AND THIRD TRIMESTER
• Avoid in FIRST trimester as folate antagonism of TMP can cause neural tube defects
•Avoid use close to term in THIRD trimester due to theoretical risk of kernicterus (hyperbilirubinemia) in newborns from competitive binding between bilirubin and sulfonamides to plasma albumin
•Concern for foetus being G6PD-deficient

3) Nitrofurantoin avoided at term (38-42 weeks) • Concern for foetus being G6PD-deficient

4) Aminoglycosides are used with caution
•8th cranial nerve toxicity in the fetus reported with older aminoglycosides –KANAMYCIN, STREPTOMYCIN; not reported for newer aminoglycosides so far

  • Beta-lactams are safe options in pregnancy
    * First-line in treatment of UTI in pregnancy
  • Choice of antibiotics based on cultures
  • Treat for 7 days for asyptomatic bacteriuria or cystitis
  • Treat for 14 days for pyelonephritis
35
Q

Monitoring for pregnancy UTI

A

Follow-up urine culture 7 days after completion of therapy

  • negative –> surveillance (monthly) cultures until delivery
  • persistent or recurrent bacteriuria
    • treat again with 7 –14 day regimen
    • consider prophylaxis until delivery
    • follow-up urine culture after delivery

-evaluation of urinary tract for anatomic or physiologic abnormalities 3-6 months postpartum

36
Q

Catheter-associated UTI definition

A

presence of symptoms or signs compatible with UTI with no other identified source of infection along with 10^2 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 h

37
Q

most common cause of nosocomial UTI

A

catheter-associated UTI

38
Q

Risk factors for development of catheter associated UTI

A
  • Duration of catheterisation
  • Colonisation of drainage bag, catheter and periurethral segment
  • DM
  • Female
  • Renal function impairment
  • Poor quality of catheter care, including insertion
39
Q

Causative organism for catheter-associated UTI

A

•Causative organisms

1) Short-term catheterisation (<7 days)
–85% single organisms – reflecting that prevailing in environment

2) Long-term (>28 days)
–95% polymicrobial (2-3 organisms)

40
Q

morbidity and mortality of Catheter UTI

A

• Symptomatic manifestation uncommon
• Studies in long-term care facilities showed <10% febrile episodes due to UTI
• Usually low-risk or not associated with excess
mortality

41
Q

Prevention for catheter associated UTI

A
  • Avoid unnecessary catheter use
  • Use for minimal duration (trial of catheter)
  • 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
42
Q

Tx for catheter associated UTI

A
  • Treatment of asymptomatic bacteriuria not recommended except prior to traumatic urological procedures
  • REMOVAL OF CATHETER should always be considered
  • If an indwelling catheter has been in place for >2 weeks at the onset of CA-UTI and is still indicated, the catheter should be replaced to hasten resolution of symptoms and to reduce the risk of subsequent CA bacteriuria and CA-UTI.
  • ABX only for symptomatic infection
  • Symptoms include new onset or worsening of fever, rigors, altered mental status, malaise, or lethargy with no other identified cause; flank pain; costovertebral angle tenderness; acute hematuria; pelvic discomfort.

•If patient is stable and fever is low grade, consider observation rather than immediate antibiotics therapy
(always have bacteria; if keep tx can get resistance)

•Urine (+/-blood) culture must be taken before antibiotics is given

43
Q

Empiric abx for catheter associated UTI

A

Start empiric antibiotics, adjust when culture & sensitivity becomes available

  • Duration of treatment: usually 7 days in those with prompt resolution of symptoms (i.e. deferverse in 72 hrs) and 10–14 days of treatment for those with a delayed response
  • Chronic suppressive therapy is not recommended.