Urinary Tract Infections Part 1 Flashcards
definition of a urinary tract infection
presence of microorganisms in the urinary tract (that can’t be accounted for by contamination)
what is the most common bacterial infection AND the most common reason for antibiotic exposure
urinary tract infection
around 60% of females will develop a UTI in their lifetime and ____% will have a recurrence within _____
25% within a year
true or false
urinary tract infections are always more common in women, regardless of age
false
rates are much higher in women, but up until men reach 65 yrs - at this point their rates are similar to women
urinary tract infections encompass a wide spectrum of clinical entities
explain this
UTI’s can range from an asymptomatic infection – acute pyelonephritis (kidneys) — sepsis
what is an upper UTI
pyelonephritis - kidney infection
what is a lower UTI
could be 3 things –
-cystitis (bladder)
-urethritis (urethra)
-prostatitis (prostate gland)
2 ways UTIs can be classified
complicated or uncomplicated
define uncomplicated vs complicated UTI in terms of who they affect
uncomplicated - affects premenopausal women of childbearing age (15-45) who are NORMAL and HEALTHY
complicated – UTI in anyone else (ie - any male)
differentiate between uncomplicated vs complicated UTI based on what they AFFECT
uncomplicated - there are no structural or functional abnormalities of the urinary tract that affect the normal flow of urine
complicated - result of a predisposing factor like a congenital abnormality/distortion of urinary tract, a stone obstruction, or some neurological deficit that INTERFERES WITH THE FLOW OF URINE
2 main causes of outpatient UTIs
e. coli (MOST - 75-90% of outpatient cases!!)
second is staph saprophyticus in young women (18-22)
which bacteria is usually a contaminant in urine samples
staph epidermidis
2 bacteria that commonly cause UTI IN hospitalized patients
pseudomonas and enterococcus
2 gram negative bacteria that can cause UTI (not pseudomonas and enterococcus)
klebsiella pneumoniae
proteus
which bacteria usually causes bacteremia and kidney abscess
staph aureus
generally differentiate between symptoms of a lower UTI vs upper
lower UTI has more localized symptoms like pain when urinating and urgency
upper UTI has those same symptoms but more constitutional symptoms as well like fever nausea, vomiting, malaise
TRUE OR FALSE
symptoms alone are not a sufficient way to diagnose a UTI
true. symptoms can be used to differentiate upper and lower, but not to diagnose a UTI itself
must have a good urine specimen AND SYMPTOMS
“gold standard” to diagnose a UTI
a positive urinalysis with a positive urine culture in a SYMPTOMATIC patient
what is usually the initial step of diagnosing a UTI?
what is done to confirm diagnosis?
initial step is urinalysis
urine culture is done to confirm, but NOT routinely done in outpatient settings for uncomplicated cystitis because MOST OF THE TIME it’s gonna be e. coli anyway
HOWEVER, urine cultures are done to confirm in pyelonephritis (upper - kidney), when treatment isn’t working, or when the patient has atypical symptoms
3 methods of urine collection and which is preferred
- midstream clean-catch method (preferred)
also catheterization and suprapubic bladder aspiration
explain the midstream clean-catch method
clean urethral opening and discard initial 20-30mL of urine
collect the midstream void and process immediately OR refrigerate if you can’t do so
catheterization is done to collect urine in which patients?
what is a potential issue with this method of collecting urine
pts who are uncooperative or unable to pee
issue is that it may introduce bacteria into the bladder – causes 1-2% of bladder infections
in what patients is suprapubic bladder aspiration done to collect urine?
explain the method
the needle is inserted directly into the bladder to aspirate the urine
its safe and painless and bypasses any contaminating organisms in the urethra
done in bbs, paraplegics (leg paralysis), and very ill patients
-these patients NEED a reliable sample to make clinical decisions
what does a urine culture do
identifies the organisms and provides the susceptibilities
(THATS IT- EVERYTHING ELSE LIKE BACTERIURIA AND HEMATURIA ARE URINALYSIS)
define bacteruria
when >100,000 CFU/mL of urine
what is pyuria
WBC in urine
> 10WBC/mm3
what does “nitrite positive” mean and what detects this
detected in urinalysis
some bacteria (like e. coli) are able to reduce nitrates to nitrite — nitrite positive indicates presence of such bacteria
what value in a urinalyis helps to identify if the patient is hydrated/dehydrated
what is reference range??
specific gravity
1.001-1.035
what component of a urinalysis is a marker for white blood cells in the urine (pyuria)
leukocyte esterase
what is a marker for common bacterial pathogens in a urinalysis?
nitrite
name 3 bacteria that DO reduce nitrate to nitrite and 3 bacteria that do NOT
DO - e. coli, klebsiella, proteus
DONT - pseudomonas, enterococci, coagulase negative staph
are WBC and RBC found in the dipstick or microscopic portion of a urinalysis
microscopic
bacteria are too numerous to count - is this consistent with a urinary tract infection?
YES
epithelial cells are too numerous to count in microcopic portion of a urinalysis - is this consistent with a urinary tract infection?
NO
this most likely indicates a contaminated culture
TRUE OR FALSE
urinalysis and urine cultures are only useful when also used in conjunction with symptoms
TRUE
bc there are many factors that can affect urinalysis results that are not bc of infection
ie - for postmenopausal women it is normal to have inflammation in urinary tract - normal for them to have high WBC and leukocyte esterase
urine collected should be testes or cultured within _______ of collection to avoid _____
within 20 mins of collection to avoid erroneously high bacteria counts
if unable to do within 20 mins, referigerate until testes
4 treatment goals for UTIs
-get rid of infecting organism(s)
-prevent/treat systemic consequences of the UTI
-prevent infection from recurring
-decrease the potential for collateral damage when we use broad spectrum antibiotics
as mentioned, 1 of the treatment goals for UTIs is to limit the collateral damage when we use broad spectrum antibiotics
name 2 components of this potential collateral damage
- breeds resistance - unwanted colonization and infection with multidrug resistant organisms
-impact on gut flora - can cause c diff
3 components of overall management of UTIs
initial evaluation
empiric antibiotics
follow up
true or false
test-of-cure is not recommended for UTIs
true
dont resend the urine to confirm infection cleared. if they feel better - it’s good enough
e. coli has been increasing its resistance to which class of antibiotics
fluoroquinolones - particularly cipro
true or false
the overall resistance rates for e. coli are higher in the US than they are in canada
true
what are some risk factors for a patient having e.coli bacterial resistance?
(within the prior 3 months of starting the antibiotic)
have a history of multi-drug resistant organisms
recently have used broad spectrum antibiotics
healthcare exposures
travel to parts of world where MDRO’s are prevalent
to optimize empiric therapy in terms of avoiding the issue of resistance, what is necessary?
have to ongoingly monitor the LOCAL prevalence of resistance
USING ANTIBIOGRAMS
prior to starting antibiotics, do what 2 things
collect urine for urinalysis and urine culture (if complicated)
3 1st line options for empiric treatment for uncomplicated cystitis
nitrofurantoin
bactrim
fosfomycin
true or false
e. coli is usually very susceptible to nitrofurantoin
true
dose of nitrofurantoin for uncomplicated cystitis
100mg Q12 5 days
dose of bactrim for uncomplicated cystitis
1 tab q12 3 days
dose of fosfomycin for uncomplicated cystitis
3g PO for 1 dose
true or false
nitrofurantoin has a lot of resistance issues
FALSE - minimal resistance
in which particular UTI is nitrofurantoin AVOIDED
pyelonephritis
most common ADR of nitrofurantoin
which 2 are really only seen wiith long term use
GI intolerance
neuropathies and pulmonary toxicity
ADRS of bactrim
rash (sjs)
hyperkalemia
photosensitivty
hematologic (pancytopenia)
which 1st line drug for uncomplicated cystitis is avoided if the local resistance prevalence is greater than 20%??
bactrim
aside from not using bactrim when local resistance prevalence is greater than 20%, when else should bactrim be avoided for UTI
if it was used for UTI in previous 3 months (resistance)
what is the only 1st line for uncomplicated cystitis that CAN be used for pyelonephritis
bactrim
fosfomycin and nitrofurantoin can’t
ADR fosfomycin
is it used often? explain
diarrhea, headache, angioedema (but generally well tolerated)
it retains activity against multi drug resistant organisms, so not really given to anyone other than those with a MDRO
also expensive
which 1st line for uncomplicated UTI is avoided in creatinine clearance less than 30mL/min
nitrofurantoin
monitoring parameters for nitrofurantoin
serum creatinine and BUN
monitoring parameters for bactrim
serum creatinine, bun, electrolytes (potassium), and watch for rash
what if the 3 first line options for acute uncomplicated cystitis cannot be used??
explain
(nitrofurantoin, bactrim, or fosfomycin (if MDRO))
use fluoroquinolones (but bad resistance profile) or beta lactams (but avoid ampicillin or amoxicillin alone - less effective than other agents)
a patient’s urinalysis and symptoms are consistent with UNCOMPLICATED CYSTITIS
allergy to sulfa. when antibiotic regimen is most appropriate
nitrofurantoin 100mg Q12H 5 days
true or false
both macrobid and fosfomycin CANNOT BE USED for pyelonephritis
TRUE
true or false
in clinical practice, fluoroquinolones are used for empiric treatment of acute pyelonephritis
FALSE
this is recommended in the guidelines, but NOT DONE IN CLINICAL PRACTICE
serious side effects. risks outweigh benefits.
tendon rupture, hypoglycemia, neuro effects, peripheral neuropathies, QT prolongation
ONLY RESERVED FOR THOSE WITH NO OTHER OPTIONS
though quinolones are recommended in the guidelines for outpatient acute pyelonephritis, they are not used
what is used in clinical practice instead?
if FQ resistance greater than 10%, ceftriazone 1g IV/IM for one dose OR gentamicin/tobramycin 5mg/kg IV/IM for one dose
or
bactrim Q12H for 14 days IF THE PATHOGEN IS KNOWN TO BE SUSCEPTIBLE
if not, potentially beta lactams, but they’re less effective for pyelonephritis. if we use them PO, first must give initial dose of long acting IV antibiotic like ceftriaxone
indications for hospitalization for acute pyelonephritis
sepsis
persistent high fever
severe pain
urinary obstruction
empiric treatment for pyelonephritis in HOSPITALIZED PATIENT
3 options - all IV
most often it’s ceftriaxone 1g (ext spectrum cephalosporin) BC IT’S NARROWEST OF THE 3 EMPIRIC OPTIONS - OTHER 2 ARE BROAD
could be aminoglycoside (genta or tobra 5mg/kg)
carbapenem - drug of choice for ESBL (etrapenem 1g)
very important consideration when choosing treatment for pyelonephritis in hospitalized patient AND outpatient pyelonephritis
FOLLOW THE CULTURES AND SUSCEPTIBILITIES
(complicated)
