by mtoom

Bookmark and Share

Front Back
Why should we care about UTIs?
  • Urinary tract is one of the most common sites of infection
  • 20-30% of women have recurrent UTIs
Describe the 2 main ways that UTIs get started?
  • 1. Ascending the urinary tract
    Urethra → Bladder → Kidney → Blood
  • 2. Seeding
    Bacteremia results in kidney infection 
What are the common UTI pathogens (6)?
  • Gram (-) Enterobacteriaceae (E. coli, Klebsiella, Proteus)
  • Enterococcus
  • Staphylococcus saprophyticus (CNS = coagulase negative staphylococci)
  • Streptococcus agalactiae (GBS)
What is the most common urinary tract pathogen?
E. coli
Describe 3 factors of Uropathogenic E. coli
  • P. fimbriae: Allows UPEC to adhere to urethral and bladder epithelium
  • Capsular polysaccharides: Inhibits phagocytosis
  • Haemolysins: Membrane damaging toxins
Name 3 host factors of the urinary tract that help to eliminate pathogens
  • Normal "flushing" mechanism
  • pH
  • Chemical content of urine
Describe 6 factors that will predispose to UTIs
  • Kidney stones: Can cause obstruction and be a source of bacterial accumulation
  • Vesicoureteral reflux: In children, predisposes to infections of the kidney
  • Neurologic problems: Leading to incomplete bladder emptying
  • Prostate hypertrophy: Leads to obstruction
  • Short urethra: Allows bacteria to ascend more easily (in women)
  • Urinary catheters: Allow for colonization of the urinary tract and impairs host defenses
When do you use urinary catheters?
As little as possible. Avoid unless clinically indicated.
  • Catheters used too liberally
  • Risk goes up 3% with every day it's in 
What is the most common type of hospital associated (ie. nosocomial) infection?
Urinary catheter associated UTI
Describe 4 guidelines for catheter use
  • Avoid unless indication
  • Hand hygiene important when inserting and manipulating
  • Maintain drainage by gravity
  • Intermittent (ie. in and out) is better than continuous
What are the 3 components to diagnosing a UTI?
  • History and physical exam to assess symptoms and signs
  • Obtain a urinalysis
  • Urine culture and susceptibility
Name 7 symptoms and 1 non-symptom of UTI

Symptoms of UTI
  • Frequency of urination
  • Dysuria
  • Urgency
  • Hesitancy
  • New onset incontinence (elderly)
  • Fever
  • Costovertebral angle tenderness (ie. pyelonephritis)

Not a symptom of UTI: Malodorous or cloudy urine
Name 7 methods for collecting urine
  • Midstream urine
  • Foley catheter
  • Suprapubic aspiration
  • Ileal conduit
  • Nephrostomy tube
  • Cystoscopy
What is clinically relevant about Midstream Urine (MSU)?
  • Allows initial stream of urine to washout contaminating bacteria of the lower urethra

Note: Should be performed after first washing the periurethral area
How do you collect urine from a Foley catheter?
  • Urine should ideally be collected from a clean foley catheter from the port
  • Never collect urine from the bag (likely contaminated and overgrown)
When do you use a suprapubic aspiration?
To collect urine from pediatric patient (not potty trained) or potentially from a spinal-cord injured patient
What is an ileal conduit?
It is a piece of small bowel (that the ureters connect to) that allows urine to come out of the abdomen wall. It is a surgical diversion of urine after a radical cystectomy.
What do you need to know about sampling urine from ileal conduits?
The sample will always grow bacteria
How do you collect urine by Nephrostomy?
Insert needle percutaneously into collecting system of kidney under CT, US or fluroscopy guidance.
What is advantage of Direct cystoscopy and selective ureteral catheterization?
Helps to localize the site of infection in patients with complicated urinary tract anatomy
How long do you have to get a urine sample to the lab?
Should be done in ~2 hours to avoid bacterial overgrowth
What are the 2 dipstick screening tests that can be done?
  • Leukocyte esterase
  • Nitrites
What does a leukocyte esterase dipstick indicate? How is a positive result interpreted?
  • Indicates WBCs (ie. inflammation) present
  • Can be due to infection, cancer, catheter
What does a Nitrite dipstick test indicate if positive? How is it interpreted?
  • Positive result means Enterobacteriaceae bacteria are present (that can reduce nitrate to nitrite)
On microscopic analysis, give DDx for RBCs in urine (6)
  • Infection
  • Kidney disease
  • Renal stone
  • Urinary tract cancers
  • Bleeding disorders
  • Contamination (menstrual blood)
Urine cultures must be collected before doing what?
Starting antibiotics
How long does it take to get urine culture results?
18-24 hours
Regarding Midstream Urine (MSU), how much bacteria is needed to constitute significant bacteriuria?
>105 colony forming units

This requirement only applies to MSU. This requirements does not apply to urine collected by a catheter. From a catheter, any quantity of bacteria may be significant.
What does it mean when urine culture results have 3 or more organisms?
Name 4 things that can affect results of a urine culture and in what way (4)?
  • Improper urine collection: Contamination
  • Improper storage of urine: Overgrowth of bacteria
  • Antibiotic treatment: Undergrowth of bacteria
  • Fluid intake
What 3 components must be incorporated to diagnose a UTI?
To diagnose, must incorporate:
  • Signs and symptoms
  • Positive urinalysis
  • Positive urine culture
  • Positive urine culture → Bacteriuria
  • Positive leukocyte esterase → Inflammation
  • Positive nitrite → Presence of bacteria that can reduce nitrate
Name 3 situations where patient with UTI needs blood cultures
  • Clinical assessment (indications: fever; pyelonephritis; immunocompromised)
  • Pediatric patient with fever
  • Patient with sepsis
Describe important principles of treatment in UTIs (6)
  • Encourage fluids
  • Use antibiotics based on local epidemiology
  • Shortest duration of therapy suggested
  • Switch IV to PO antibiotics ASAP
  • Reevaluate empiric choice when culture susceptibility results available
  • Remove catheter unless absolute indication
Should Ciprofloxacin and TMP/SMX be used to treat UTIs?
No, there is high amounts of resistance due to past overuse
What are the empiric choices for cystitis?
Note: Cannot use these for pyelonephritis, only cystitis

Amoxicillin-Clavulanate also good empiric
What 3 antibiotics used for UTIs should be avoided in pregnancy?
  • Nitrofurantoin
  • Quinolones
How do you treat a septic patient with a UTI?

IV antibiotics
  • Piperacillin-Tazobactam IV + Gentamicin
Who commonly gets recurrent cystitis?
Sexually active females
For a first episode of Acute Cystitis in a female, how do you manage it?
  • Often resolves spontaneously
  • Screen for pyruria (neutrophils in urinalysis)
  • Urine cultures not needed
  • If no response to therapy, evaluate for other genitourinary infections
What should be ruled out in recurrent cystitis in men?
  • Prostatitis
  • Prostatic hypertrophy
What is the empiric treatment (2) for cystitis? Name 2 alternative regimes.
Empiric treatment
  • Nitrofurantoin
  • Fosfomycin
Alternative regimes
  • Cefixime
  • All: TMP/SMX, trimethoprim, ciprofloxacin
If a UTI recurs after treatment, it can either be a reinfection or a relapse. Which is more common? Do you repeat cultures?
  • Reinfections are more common (>90%) → Occur after first month
  • Relapses (occur within 2 weeks of completing treatment) → Treat with longer course of antibiotics
What is pyelonephritis? How do you differentiate from a lower UTI (2)?
It is a kidney infection
  • Lower urinary tract symptoms plus fever and costovertebral angle tenderness 
What are the concerns with recurrent pyelonephritis?
  • Can damage renal tissue, leading to loss of renal function
  • May result in secondary bacteremia
What are the treatments for Pyelonephritis (Community [1] vs Hospital [2])?
  • Cefixime
  • Alternatives: Amox/Clav, Cipro, TMP-SMX
  • Ceftriaxone IV
  • Gentamicin IV

Note: Fever in pyelonephritis lasts longer than 3 days, so base treatment response on other factors
What is meant by "complicated UTI"?
UTIs in patients with functional abnormalities of GU tract
  • Transplants
  • Congenital defects
  • Obstructions 
Is asymptomatic bacteriuria common? Should antibiotics be given?
Yes, it is common.

No, in fact, giving antibiotics to asymptomatic bacteriuria is a major cause of resistance.
Name 2 situations where antibiotics should be given to asymptomatic bacteriuria.
  • Pregnant
  • Instrumentation of urinary tract (eg. cystoscopy)
Why must asymptomatic bacteriuria be treated in pregnant women?
Due to increased incidence of:
  • pyelonephritis
  • preterm labour
  • low birthweight
Should we screen for asymptomatic bacteriuria in pregnant women?
Yes, at 12-16 weeks
  • Perform post-treatment urine cultures and monthly urine cultures for remainder of pregnancy 
x of y cards Next >|