Urinary Tract Infections Flashcards
Types of UTIs
-Pyelonephritis
-Prostatitis
-Cystitis
Which gender are UTIs more common?
Female
Risk factors for UTI
-Urologic instrumentation
-Urinary tract obstruction
-Neurogenic bladder
-Renal transplantation
Characteristics of complicated UTIs
-Anatomical abnormality of urinary tract
-Recent urologic procedure or instrumentation
-Immunocompromised patients
-Recurrent infections despite appropriate treatment
-Male sex
-UTI in pregnancy
Examples of an anatomical abnormality in urinary tract
-Obstruction (commonly due to calculi (stone))
-Hydronephrosis (fluid swelling around kidney)
-Renal tract calculi
-Colovesical fistula (connects the bladder to the colon)
Examples of a recent urologic procedure or instrumentation
-Placement of nephrostomy tubes (tube above an obstruction to drain urine)
-Ureteric stenting (increases the flow of urine if there is no obstruction)
-Suprapubic catheter
-Foley catheter
What is an uncomplicated UTI?
-Patient not meeting criteria for complicated UTI
-Pre-menopausal women with normal anatomy
Most common pathogen seen in UTIs
E. Coli
What other pathogens are seen in complicated UTIs, catheter-associated UTIs and prostatitis?
-Enterococcus spp.
-Pseudomonas
-Other enteric GNRs
Signs and symptoms of a UTI
-New onset of dysuria, increased urinary urgency and increased urinary frequency
-Suprapubic heaviness sensation and/or pain
-Urine may be foul smelling or turbid (not correlated with infection)
-Hematuria can occur in some cases (alone does not mean complicated infection)
Signs and symptoms of pyelonephritis
-Same as UTI
-Systemic signs of infection - chills, fever, rigors, nausea, vomiting, diarrhea
-Flank pain - costovertebral angle (CVA) tenderness
Clinical presentation of a complicated UTI
-Classic UTI symptoms commonly present, but not always
-Fever
-Malaise
-Altered mental status
-Urinary incontinence
-Change in appetite
Clinical presentation of catheter-associated UTI
-Classic UTI symptoms often not present
-Pain over kidney and bladder
-Fever
-Lethargy and malaise
If a patient has altered mental status, does that mean they have a UTI?
NO, altered mental status alone does not automatically mean UTI is present
What are the microbiologic criteria that must be met to diagnose a UTI?
-10^5 or more of 1 or more bacterial species from a clean void
-10^3 or more of 1 or more bacterial species from a catheter (placed in last 48 hours)
How do you diagnose cystitis?
Cystitis symptoms must be present and microbiologic criteria must be met
How do you diagnose pyelonephritis?
Pyelonephritis symptoms must be present and microbiologic criteria must be met
What are the four key components of a urinalysis that are related to UTI?
-Bacteria present (depends on how lab reports it)
-WBC present (10 or more cells)
-Leukocyte (WBC) esterase present
-Nitrite may or may not be present (enterobacterales convert nitrates to nitrites)
How quickly can a urinalysis be completed?
Hours
Why do you get a urine culture in a UTI?
Assists with identification of organism and confirm susceptibility to antibiotic selection
Would you repeat a urine culture after treament?
No
How quickly can a urine culture be completed?
2-3 days
What are the two tests that can be done to diagnose a UTI or pyelonephritis?
-Urinalysis
-Urine culture
When do you treat asymptomatic bacteruria?
Only in pregnant patients
The four characteristics of an ideal oral antibiotic for UTI
-Medium to high bioavailability (50% and above)
-Medium to high renal excretion (50% and above)
-Low risk of “collateral damage” (tendency to cause bacterial resistance) and adverse effects
-High likelihood of susceptibility
Commonly used oral agents for outpatient UTI treatment
-Nitrofurantoin (uncomplicated only)
-Bactrim
-FQs - cipro, levo
-Fosfomycin (uncomplicated only)
-Beta-lactams
What beta-lactams are commonly used for the treatment of UTI?
-Cephalexin
-Cefadroxil
-Cefpodoxime
-Augmentin
-Amoxicillin (only after susceptibility is confirmed) (not used empirically because E. Coli resistance is high)
Outpatient treatment duration for uncomplicated UTI
3-7 days
Outpatient treatment duration for complicated UTI
7-14 days
What is the percent resistance where an agent is no longer recommended for empiric treatment?
20%
Which drugs have a resistance rate of over 20%?
-Bactrim
-Cipro
Do beta-lactams have less effectiveness and have more side effects than other UTI antimicrobials?
No, those studies sucked
Commonly used empiric therapies for UTI in hospitalized patients
-Ampicillin 2 grams IV Q6H + gentamicin 5 mg/kg (AdjBW) IV Q24H (first-line at IU Health but almost everywhere else uses ceftriaxone first line)
-Cefazolin 1-2 grams IV Q8H +/- gentamicin 5 mg/kg (AdjBW) IV Q24H
-Ceftriaxone 1-2 grams IV Q24H
-Cefepime 1 gram IV Q8-12H
-Gentamicin 5 mg/kg (AdjBW) IV Q24H
What percent likelihood is ampicillin + gentamicin to cover all organisms in a UTI?
91.6%
What percent likelihood is ceftriaxone to cover all organisms in a UTI?
72.2%
Considerations for UTI treatment in hospitalized patients
-Bacteremia can occur in patients with complicated UTI and pyelonephritis
-De-escalate to narrowest antibiotic option once urine culture with susceptibilities return
How would you change treatment duration when treating a patient with urosepsis?
Do not lengthen treatment duration, treat for 7-14 days
What must you consider when selecting an antibiotic to treat prostatitis?
-Must consider antibiotic penetration into the prostate
-No active transport of antibiotics into the prostate tissue
-Need an option with high level of free drug, low protein binding
Recommended treatment options for prostatitis
-FQs
-Bactrim
-Some beta-lactams (cephalexin, Augmentin)
Treatment duration for prostatitis
2-4 weeks
Definition of recurrent UTI
-3 or more infections in 1 year
-2 or more infections in 6 months
Potential causes for recurrent UTIs
-Sexual intercourse and diaphragm/spermicide use
-Postmenopausal women
-Urologic abnormality
How do you treat recurrent UTI?
-May consider prophylactic antibiotic if no correctable cause identified
-Select narrowest spectrum possible
