IC13 PR3151 UTI Flashcards
What is asymptomatic bacteriuria?
isolation of significant colony counts of bacteria in the urine without UTI symptoms
Difference between asymptomatic bacteriuria VS UTI?
Both have isolation of significant colony count but UTI displays symptoms.
What is the spectrum of UTI
Cystitis
Pyelonephritis
Eventually UTI with bacteremia/sepsis/death.
When is screening for asymptomatic bacteriuria done?
1) pregnant women
2) patients going for urologic procedure where mucosal trauma or bleeding is expected e.g., TURP (transuretal/rectal removal of prostate), cystoscopy w biopsy
Why is screening and treatment for asymptomatic bacteriuria not commonly done?
E.g., elderly in long term care, spinal cord, indwelling catheter use –> treatment did not decrease risk of subsequent UTI in these groups.
Indications for screening and treatment of asymptomatic bacteriuria in pregnant women?
and when to screen?
To prevent pyelonephritis (about 20% chance), preterm labor, infant low birth rate.
Screen at first visits (12-16 wk gestation)
If bacteriuria: treat with active abx based on AST for 4-7 days.
Indications for screening and treatment of asymptomatic bacteriuria in patients undergoing urologic procedure with possible mucosal trauma/bleeding?
and when to screen?
what to do if confirmed bacteriuria
Prevent post-operative bacteremia and urosepsis
Screen prior to procedure.
If bacteriuria: treat as SAP.
THEN
obtain culture and treat based on culture and AST
When to initiate treatment of ASB/UTI during mental status change?
When delirium, falls, confusion symptoms appear in the presence of urinary symptoms + systemic symptoms
What is the anatomical classification of UTI?
Upper:
- pyelonephritis (kidney)
Lower:
- cystitis (bladder)
- urethritis (urethra)
- prostatitis (prostate)
- epididymitis (epididymis)
Catheter associated
What is the epidemiology of UTI (age and prevalence factors)
older age increases prevalence.
0-6 months –> males > females due to higher rate of structural and functional abnormalities
1yo - adult –> females > males because of shorter urethra + abx properties of male prostate
> 65 –> equal risk due to increased comorbidities e.g., BPH, urine incontinence from muscular dysfunction, stroke…
What is the pathogenesis of ascending UTI?
Colonic or fecal flora colonise periurethra area/urethra and ascends to bladder and kidney
What are the risk factors of ascending UTI?
Females due to shorter urethra, use of spermicides, diaphragm contraceptive.
What are the organism examples for ascending UTI?
E K P
e coli
klebsiella
proteus
What is the pathogenesis of descending (hematogenous) UTI?
organ at distant primary site (heart valve, bone) travel through blood stream (bacteremia) to the urinary tract causing UTI
What are the organism examples for descending (hematogenous) UTI?
S. aureus,
Mycobact TB
What are the three factors determining UTI development?
1) Host defence mechanism
2) Size of incolum (bact load)
3) Virulence/pathogenicity of microorganism
What are the methods in host defence mechanism for preventing UTI?
1) antibact properties of urine and prostatic secretion.
2) anti adherence mechanisms of bladder
3) infl response with polymorphonuclear leukocytes (PMNs) –> phagocytosis –> prevent control spread.
4) bacteria in bladder will stimulate micturition and increased diuresis
How does size of inoculum affect UTI dev?
obstruction and urinary retention
What are some virulence/pathogenicity factors increasing dev of UTI (RE: Ecoli)
E.G., E COLI resistant to washout or removal by antiadherent mechanism of bladder.
Risk factors for UTI? (x11)
Females > males
Sexual intercourse
UT abnormality (BPH, kidney stone,
urethral stricture, Vesicoureteral reflux)
Neurologic dysfunction (stroke, diabetes, spinal cord inj)
Anti cholinergic drugs (1st gen antihistamines, atropine)
Catheterisation and other mechanical instrumentation
Diabetes (neuropathy + glycosuria)
Pregnancy
Use of diaphragm/spermicide contraceptive (alter flora)
Genetic association (positve fam hist)
Previous UTI
Non-phx methods to prevent UTI?
1) Drink lots of fluids 6-8cups
2) Urinate frequently
3) Urinate shortly after sex
4) Wipe from front to back for women, esp after bowel movement
5) Cotton underwear and loose fitting clothes to keep area dry.
6) modify birth control if using spermicide or diaphragm
What are the two classifications of UTI?
uncomplicated and complicated.
Classification of uncomplicated UTI?
usually in pre menopausal, non pregnant (healthy) women with no history suggestive of abnormal urinary tract
usually ambulatory women
Classification of complicated UTI?
usually associated w serious outcomes and risk for therapy failure
uti in men, children, pregnant women
presence of complicating factors/risk factors: functional and structural abnormalities of UT, genitourinary instrumentation, DM, immunocompromised host
Clinical spectrum of complicated UTI?
mild cystitis to life threatening urosepsis
subjective symptoms of lower UTI (cystitis)?
dysuria, urgency, frequency, nocturia, suprapubic heaviness or pain, gross hematuria (blood in urine)
subjective symptoms of upper UTI (pyelonephritis)?
fever, rigor, headache, N/V, malaise, flank pain, costovertebral tenderness(renal punch), abdomen pain
note that pyelonephritis more likely to present with systemic symptoms of infection as well.
how to obtain objective parameters for UTI? what are the 3 methods of XX
urinalysis and culture:
3 methods
1) midstream clean catch
2) catheterization
3) suprapubic bladder aspiration
What is in the UFEME report for objective clinical diagnosis?
WBC
- >10 wbcs/mm3 = pyuria (pus in urine)
- presence of inflammation
RBC
- >5/HPF or gross = hematuria
- frequently in uti but non-specific
Microorgs
- bact or yeast w gram stain
WBC casts
- masses of cells/proteins that form in renal tubules indicate upper tract infection
Clinical spectrum of uncomplicated UTI? i.e. problem
Mild cystitis to severe pylonephritis
What does the chemical urinalysis (dipstick) test?
1) nitrite
2) leukocyte esterase
Level of WBC indicating pyuria?
> 10wbc/mm3
Level of RBC indicating hematuria?
microscopic >5/HPF or gross
Level of bacteria to indicate positive nitrite test (dipstick)?
10^5 bacteria/mL
What does the nitrite level test in dipstick test?
gram negative bact
it reduces nitrate to nitrite
How do false negative results appear in nitrite test (dipstick)?
G(+) orgs and pseudomonas
Low urinary pH
frequent voiding
dilute urine
What does the LE level show in dipstick test?
esterase activity of leukocytes in urine, which correlates with pyruia (>10wbc/mm3)
When to and not to obtain urine culture?
Not needed in uncomplicated cystitis
Needed in
pregnancy
recurrent uti
pyelonephritis
catheter associated uti
all men with uti
What are the likely pathogens for uncomplicated or comm acquired UTI?
Ecoli (85%)
Staph Saprophytic (5-15%)
Others:
Enterococcus faecalis
Kleb pneu
proteus