UTI Flashcards
definition of asymptomatic bacteriuria (ASB)
urine got bacteria (bacteriuria) but X stymptoms
UTI
- urine got bacteria + urinary symptoms
- cystitis -> pyelonephritis -> UTI w bacteraemia/sepsis/death
what population is ASB especially common in?
old, women, long term indwelling urinary catheter
indication of screening/treatment of ASB
1) pregnant women
- prevent pyelonephritis, preterm labour, infant low birthweight
- screen at one of the visits (12-16 wk gestation period)
- bacteriaemia -> treat w Abx according to AST for 4-7 days
2) pt undergoing urologic procedure where mucosal trauma/bleeding expected
- prevent bacteriaemia & urosepsis
- screen prior to procedure
- bacteriuria -> active Abx as SAP
- X include placement of urinary catheter
epidemiology of UTI
increases prevalence w age
1) 0 - 6 months: males > females
2) 1 - adult: females > males
3) > 65 yo: equal
pathogenesis of UTI - ascending
- colonic/fecal flora colonise periurethra area/urethra -> ascend to bladder & kidney
- factors that increase risk
1) females (shorter urethra)
2) use of spermicide & diaphragms as contraceptives - types of organisms: E.coli, Klebsiella, proteus
pathogenesis of UTI - descending
- more rare
- organism at distant primary site -> bloodstream (bacteriaemia) -> urinary tract -> UTI
- types of organism: staph aureus, myco tb
what are the 3 factors determining development of UTI
1) competency of natural host defense mechanism
2) size of inoculum
3) virulence/pathogenicity of microorganism
factors determining development of UTI - competency of natural host defense mechanism
- bacteria in bladder stimulate micturition w increased diuresis -> increase urge to empty bladder -> pee out urine
- urine & prostatic secretion antibacterial properties
- bladder anti-adherence mechanism: prevent bacterial attachment to bladder
- inflammatory response w polymorphonuclear leukocyte (PMNs) -> phagocytosis -> prevent/control spread
factors determining development of UTI - virulence & pathogenicity of microorganism
- bacteria w pili resistant to
1) washout (E.coli)
2) removal by anti-adherence mechanism of bladder
risk factors for UTI
1) females > males
2) sexual intercourse
3) abnormalities of UT
- prostatic hypertrophy, kidney stone, urethral strictures, vesicoureteral reflux
4) neurologic dysfunction
- stroke, DM, spinal cord injuries
5) anti-cholinergic drugs
- 1st gen antihistamine, atropine
- cause urinary retention
6) catheterisation & other mechanical instrumentation
7) DM
8) pregnancy
9) use of diaphragm & spermicide
10) genetic association
- +ve family history, 1st degree female relative
11) previous UTI
lifestyle modification to prevent UTI
1) hydration to flush out bacteria
2) urinate frequently & go when first feel urge
3) urinate shortly after sex
4) women: wipe from front to back after bowel movement
5) cotton underwear & loose fitting clothes to keep area dry
6) if using diaphragm/spermicide: consider changing birth control method, unlubricated condoms/spermicidal condom increase irritation -> help bacteria grow
classification of UTI based on sypmtoms
1) complicated
- associated w conditions that increase potential for serious outcomes/risk for therapy failure
** UTI in men, children, pregnant women
** presence of complicating factors: functional & structural abnormalities of urinary tract, genitourinary instrumentation, DM, immunocompromised host
2) uncomplicated
- none of the above
- healthy premenopausal, non-pregnant women w no history suggestive of abnormal urinary tract
subjective evidence for lower UTI
1) dysuria, urgency, frequency
2) nocturia
3) suprapubic (hypogastric) heaviness/pain
4) gross haematuria: pee blood
subjective evidence for upper UTI
- more serious
- fever, headache, N/V, malaise, flank pain, costovertebral tenderness (renal punch), abdominal pain
additional subjective symptoms elderly face for UTI
altered mental status (more drowsy, less alert), small GI symptoms, change eating habits
urine collection method
1) midstream clean-catch
2) catheterisation
3) suprapubic bladder aspiration
when to get urine culture
1) pregnant women
2) recurrent UTI (relapse within 2 wks/frequent)
3) pyelonephritis
4) catheter-associated UTI
5) all men w UTI
what is done during urinalysis
UFME, chemical analysis
UFME components
1) WBC
- pyuria: > 10 WBC/mm^3
- presence of inflammation but may/may not be cuz of infection
- symptomatic pt: correlate w significant bacteriuria
- absence of pyuria = unlikely UTI
2) RBC
- presence = haematuria (microscopic > 5/HPF or gross)
- frequent in UTI but non specific
3) microorganism: gram stain
4) WBC cast
- mass of cell & protein that form in renal tubule
- indicate upper tract infection/disease (kidneys X involved)
chemical urinalysis through dipstick components
1) nitrite
- +ve test = gram -ve bacteria present cuz only gram -ve reduce nitrate to nitrite
- at least 10^5 bacteria/mL
- possible false positives
** gram pos, Pseudomonas
** low urinary pH
** frequent voiding
** dilute urine
2) leukocyte esterase (LE)
- +ve test = esterase activity of leukocyte in urine
- correlate w significant pyuria
likely pathogen for uncomplicated/community acquired UTIs
E.coli, staph sacrophyticus, enterococcus faecalis, klebsiella pneumoniae, proteus spp
likely pathogen for complicated/hospital acquired UTIs
E.coli, enterococci, proteus spp, klebsiella spp, enterobacter spp, pseudomonas, drug resistant strain (ESBL producing E.coli)
when to consider other site of infection for UTI
staph aureus, yeast/candida possible contaminant
determining need to treat for UTI
X treat if X symptoms of UTI (ASB) unless pregnant women & urologic procedure in which mucosal trauma/bleeding expected
types of UTI
1) cystitis in women
2) community acquired pyelonephritis in women
3) community acquired UTI men
4) nosocomial/healthcare associated UTI
5) catheter-associated UTI
6) UTI in pregnancy
cystitis in women - 1st line
1) PO cotrimoxazole
2) PO nitrofurantoin
cystitis in women - alternatives if allergic
1) PO beta lactam for 5-7 days
- cefuroxime, augmentin
2) PO fluoroquinolone 3 days
- ciprofloxacin, levofloxacin
- X use if possible because associated w disabling effect
complicated cystitis in women
- longer treatment (7-14 days)
- consider fosfomycin
** X 1st line cuz high rate of resistance
** used for cystitis caused by ESBL producing E.coli
community acquired pyelonephritis in women - normal
1) PO fluoroquinolone (ciprofloxacin, levofloxacin)
2) PO cotrimoxazole
3) PO beta-lactam (cefuroxime, augmentin)
community acquired pyelonephritis - initial IV therapy
- severely il pt who require hospitalisation
- pt X tolerate oral
- types
1) IV ciprofloxacin
2) IV cefazolin
3) IV augmentin
4) +/- IV/IM gentamicin (work for gram -ve ESBL, X work for bacteriaemia) - switch to oral after improve/can tolerate oral
community acquired UTI for men - cystitis wo prostatitis concern
- same as complicated cystitis in women
community acquired UTI for men - cystitis w prostatitis/pyelonephritis concern
1) PO ciprofloxacin
2) PO cotrimoxazole
- 10-14 days
- 6 wks if prostatitis confirmed
what is nosocomial UTI
onset of UTI > 48h after hospitalisation
possible causes of nosocomial/healthcare-associated UTI
pseudomonas, other resistant bacteria
empiric therapy for nosocomial/healthcare-associated UTI
broad spectrum beta lactam
1) IV cefepime +/- IV amikacin
2) IV imipenem or IV meropenem
3) PO levofloxacin, PO ciprofloxacin
- duration 7-14 days
- consider oral for less sick pt
definition for catheter-associated UTI (CAUTI)
UTI S&s + X identified source of infection + 10^3 cfu/mL of ≥ 1 bacterial species
catheter-associated UTI (CAUTI) Risk factors
1) duration of catherisation
2) colonisation of drainage bag, catheter, periurethral segment
3) DM
4) female
5) impaired renal function
6) poor quality of catheter care (insertion)
causative organism for catheter-associated UTI
short term (< 7 days): single organism
long term (> 28 days): polymicrobial
symptoms for CAUTI
new/worsen fever, rigor, altered mental status, malaise, lethargy w no identified cause, flank pain, costovertebral angle tenderness, acute haematuria, flank pain, change lab values
general treatment for CAUTI
- X treat asymptomatic
- consider remove catheter
- if CAUTI occur when IDC > 2 wks & still indicated then replace catheter
- Abx only for symptomatic
empiric treatment for CAUTI
1) IV imipenem or IV meropenem
2) IV cefepime +/- IV amikacin
3) PO/IV levofloxacin
4) PO cotrimoxazole (women ≤ 65 w CAUTI wo upper urinary tract symptoms after indwelling catheter removed)
- 7 days, 10-14 if delayed response
CAUTI prevention
1) avoid unnecessary catheter
2) use for minimal duration
3) change long-term indwelling before blockage likely to occur
4) use of closed system (X a lot of fiddling, X introduce microorganism)
5) ensure aseptic insertion technique
6) x recommend topical/prophylactic antiseptic/Abx & chronic suppressive Abx
what to avoid for pregnant UTI
1) ciprofloxacin
- potential fetal cartilage damage & arthropathies in animal studies
2) cotrimoxazole
- 1st trimester: folate antagonism of TMP -> neural tube defect
- 3rd trimester: kernicterus in newborn
- foetus maybe G6PD deficiency
3) nitrofurantoin
- X at term (38-42 wks)
- concern about G6PD deficiency
what to use w caution for pregnant UTI
1) aminoglycosides (neural tox)
what is safest to use for pregnant UTI
- beta lactams
- 4-7 days asymptomatic bacteriuria/cystitis
- 14 days pyelonephritis
monitor response
- resolution by 24-72 hrs
- if X respond within 2-3 days/persistently positive culture -> reinvestigate to exclude bacterial resistance, possible obstruction, renal abscess, other disease process
adjunctive therapy for UTI
1) fever & pain
- paracetamol & NSAID
2) vomiting
- rehydration
3) urinary symptoms
- phenazopyridine
** topical analgesic on urinary tract mucosa -> symptomatic relief
** treatment limited to duration of symptoms
** X G6PD
** N/V, orange-red discolouration
nonpharmaco for UTI
1) cranberry juice
2) intravaginal estrogen cream
3) lactobacillus probiotics
