UTI Flashcards
Difference between asymptomatic bacteruria and UTI?
Both: isolation of significant colony counts of bacteria in urine
ASB: without symptoms of UTI
When to screen & treat ASB? (2)
Pregnant women
Patients going for urologic procedure in which mucosal trauma or bleeding is expected
List 5 risk factors for UTI:
- Catheterization & other mechanical instrumentation
- Pregnancy
- Females > males
- Sexual intercourse
- Abnormalities of urinary tract e.g. kidney stones, vesicoureteral reflux
- Neurologic dysfunctions e.g. stroke, diabetes, spinal cord injuries
- Anti-cholinergics
- Diabetes
- Use of diaphragms & spermicides
- Genetic association (positive family hx)
- Previous UTI
What classifies as uncomplicated UTI?
Healthy premenopausal, non-pregnant with no history suggestive of an abnormal urinary tract
What classifies as complicated UTI?
UTI in men, pregnant women, children
Complicating factors: diabetes, functional and structural abnormalities of urinary tract, genitourinary instrumentation, immunocompromised host
Labs for UTI? (2):
Microscopic urinalysis - UFEME:
* WBC:
* * >10 WBC/mm3
* * Signifies presence of inflammation, may or may not be due to infection
* * Absence of pyuria= unlikely to be UTI
* RBCs:
* * Presence (microscopic >5/HPF or gross) = hematuria
* * Frequently occurs in UTI but non-specific
* Microorganisms
* * Identify bacteria or yeast using gram-stain
* WBCs casts
* * Masses of cells & proteins that form in renal tubules (in kidneys)
* * Indicate upper tract infection/ disease
Chemical urinalysis (dipstick)
* Nitrite
* * Positive test detects presence of gram-negative bacteria
* * Only gram-negative organisms reduces nitrate to nitrite
* Leukocyte esterase
* * Positive test detects esterase activity of leukocytes in urine
* * Correlates with significant pyuria (>10 WBCs/mm3)
When to obtain urine cultures (UTI)?:
May be necessary for:
* Pregnant women
* Recurrent UTI (relapse within 2 weeks or frequent)
* Pyelonephritis
* Catheter-associated UTI
* All men with UTI
What are the likely pathogens for uncomplicated/ community acquired UTIs?
E.coli (>85%), staphylococcus saprophyticus (5-15%)
Others:
* Enterococcus faecalis
* Klebsiella pneumoniae
* Proteus spp.
What are the likely pathogens for complicated or healthcare-associated UTIs?
E. coli (~50%)
Enterococci
Proteus spp., Klebsiella spp, Enterobacter spp, P. aeruginosa
What are the healthcare associated risk factors in UTI? (4)
- Hospitalization in the last 90 days
- Current hospitalization 2 or more days
- Recent antimicrobial use
- Residence in nursing home
Is there a need to treat positive urine cultures?
No if patient does not have symptoms of UTI except for:
* Pregnant
* Patients going for urologic procedure in which mucosal/bleeding is expected e.g. cystoscopy
Empiric antibiotics for uncomplicated cystitis in women
1st-line:
* Nitrofurantoin x5d
* Co-trimoxazole x3d
* Fosfomycin 3g single dose
Alternatives:
* PO beta-lactams x5-7d
* Augmentin 625mg BD
* Cephalexin 25-500mg QID
* Cefuroxime 250mg BD
PO fluoroquinolones x3d:
* PO ciprofloxacin 250mg BD
* PO levofloxacin 250mg daily
What is the treatment for complicated cystitis in women?
Same as uncomplicated cystitis in women except:
* Treat for longer duration e.g. 7-14 days
* Fosfomycin dose for complicated cystitis: PO 3g EOD x 3 doses
What are the empiric antibiotics for community acquired pyelonephritis in women?
PO fluoroquinolones:
* PO ciprofloxacin 500mg BD x 7 days
* PO levofloxacin 750mg daily x 5 days
PO Co-trimoxazole 800/160mg BD x 10-14 days
PO beta-lactam x10-14 days:
* Cefuroxime 250-500mg BD
* Augmentin 625mg TDS / 1g BD
* Cephalexin 500mg QID
IV options for severely ill patients who require hospitalisation OR unable take oral drug
* IV augmentin 1.2g Q8H and/or IV/IM gentamicin 5mg/kg
* IV ciprofloxacin 400mg BD
* IV cefazolin 1g q8h
What are the empiric antibiotics for community acquired UTI in men?
For cystitis:
* Same regimen as complicated cystitis in women (treat for longer duration)
For prostatitis or pyelonephritis in men:
* PO ciprofloxacin 500mg BD or
* PO Co-trimoxazole 800/160mg BD
Treat for 10-14 days, but will need longer duration if prostatitis is confirmed (6 weeks)
What does Nosocomial UTI means?
onset of UTI >48h post admission
What are some examples of healthcare-associated pyelonephritis?
Patients who have been hospitalized or underwent invasive urologic procedures in the last 6 months, has an indwelling catheter etc.
What additional microorgansisms should be considered when treating nosocomial/healthcare-associated Pyelonephritis?
Possibility of pseudomonas and other resistant bacteria (e.g. extended beta-lactamase producing E. coli and Klebsiella)
What are some recommended antibiotic regimen for nosocomial/healthcare-associated pyelonephritis?
- IV cefepime 2g Q12H +/- IV amikacin 15mg/kg/d
- IV imipenem 500mg Q6H or IV meropenem 1g Q8H
- PO levofloxacin 750mg (for less sick patients)
- PO ciprofloxacin 500mg BD (for less sick patients)
Treat for 7-14 days, initial therapy should be modified when result of urine culture and susceptibility becomes available
What is the definition of catheter associated UTI? (4)
1) presence of signs and symptoms compatible with UTI
2) With no other identified source of infection
3) With 10^3 cfu/mL of 1 or more bacterial species in a single catheter urine specimen
4) in patients with indwelling urethral, suprapubic or intermittent catheterization or in a midstream voided urine specimen from a patient whose catheter has been removed within the previous 48h
Risk factors for development of catheter-associated UTI?
- Duration of catheterisation
- Colonisation of drainage bag, catheter and periurethral segment
- Diabetes mellitus
- Female
- Renal function impairment
- poor quality of catheter care, including insertion
When should antibiotics be initiated for catheter-associated UTI?
Antibiotics should only be initiated for symptomatic infection for catheter-associated UTI
* 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
Urine (+/- blood) culture must be taken before antibiotics is given
What are some empiric treatment options for catheter-associated UTI? What is the duration of treatment?
1) IV Cefepime 2g Q12H +/- IV Amikacin 15mg/kg (1 dose)
2) IV imipenem 500mg Q6H or IV meropenem 1g Q8H
3) PO/IV levofloxacin 750mg x5d (for mild CA-UTI)
4) Co-trimoxazole 960mg BD x3d (for women 65y/o or younger, with CA-UTI without upper urinary tract symptoms after an indwelling catheter has been removed)
Duration of treatment: usually 7 days in those with prompt resolution of symptoms (i.e. deferverse in 72h) and 10-14 days of treatment for those with delayed response
Is chronic suppressive therapy recommended for catheter-associated UTI?
NO
Which class of antibiotics is first-class option for UTI management in pregnancy?
Beta-lactams
What is the duration of treatment of asymptomatic bacteruria or cystitis in pregnant women?
4-7 days
What is the duration of treatment for pyelonephritis in pregnant women
14 days
Which classes of antibiotics should be avoided in the treatment of UTI in pregnant women? Why?
1) Fluoroquinolones (avoid)
* reports of fetal cartilage damage and arthropathies in animal studies and occassional human case reports in children; not confirmed in humans
2) Co-trimoxazole (avoid in 1st and 3rd trimester)
* Avoid in 1st trimester as folate antagonism of TMP can cause neural tube defects
* avoid use close to term in 3rd trimester due to theoretical risk of kernicterus in newborns from competitive binding between bilirubin and sulfonamides to plasma albumin
* Concern for fetus being G6PD deficient
3) Nitrofurantoin (avoid at term 38-42 weeks)
* concern for fetus being G6PD deficient
4) Aminoglycosides used with caution
* 8th cranial nerve toxicity in fetus reported with older aminoglycosides (kanamycin, streptomycin), not reported for newer aminoglycosides so far
List 2 adjunctive agents to help manage urinary symptoms in patients with UTI
1) Phenazopyridine (Urogesic)
* Dose: 100-200mg TDS
* An azo dye and exerts topical analgesic relief on the urinary tract mucosa to provide symptomatic relief
* treatment should be limited to the duration of symptoms
* DO NOT USE IN G6PD DEFICIENCY
* ADR: nausea, vomiting, orange-red discolouration of urine and stool
2) Urine alkalinizer: relief discomfort in mild UTI, unproven benefit
In which group of patients do we need to do a repeat culture to document clearance of UTI?
Pregnant women
