Are you ready to talk about the
dreaded urinary tract infection?
We’re going to cover some
epidemiology and some microbiology,
but mostly discuss some pearls that, I think,
will really help you in practice
regarding diagnosis and management.
So, in terms of epidemiology,
definitely more females than
males get urinary tract infections.
In fact, over a lifetime,
about half of all women experience
a urinary tract infection.
And of course, E. coli cause most cases of UTI,
but certainly have to think
about other less common organisms,
Staph saprophyticus, Klebsiella, Enterobacter.
And the symptoms,
I think you know, they're fairly classic,
dysuria being the most common,
frequency of urination.
And just those two symptoms alone,
without any vaginal symptoms,
such as vaginal discharge or burning,
has a 90% positive predictive value
in identifying urinary tract infections.
And this is something that I've actually learned
that I didn’t necessarily know because
I usually want patients to
come in and get checked out.
But if a – particularly a female patient
calls in and complains of dysuria,
along with increased frequency,
no vaginal symptoms,
they actually did a study and found that only 5% of cases
of urinalyses were negative in a study of telephone management.
So, these cases actually can be managed over the phone
and might be a good indication to give
antibiotics just right there on the spot
to help treat the UTI.
Because physical examination is fairly limited
for identifying urinary tract infection.
Classic is suprapubic tenderness to palpation,
but only one in five women at most actually have
significant suprapubic tenderness to palpation.
Always check for costovertebral angle tenderness because
of the risk for ascending infection and pyelonephritis.
But I do think that one pearl I've
learned in managing patients
with suspected UTI is that there's a difference
between costovertebral angle tenderness
that’s mild where it’s like,
yes, that kind of hurts.
If it’s pyelonephritis or a perinephric abscess
or some more severe infection,
touching that back,
just even a gentle touch or a light touch like that,
will really make the patient
jump. It really hurts.
So, if it’s just a mild kind of soreness,
that doesn’t necessarily qualify as
costovertebral angle tenderness,
because once I chart CVAT,
I have to treat like I'm treating pyelonephritis,
and that's different from most UTIs.
Patients, of course, get a urinalysis.
Urine culture isn't necessary for every case,
and this may come up on your examination,
but certainly for more complicated cases.
Recurrent UTIs, women who are pregnant,
immunocompromised or immunocompromising
conditions and diabetes,
all those patients get routine cultures,
but a healthy younger woman
doesn't need routine culture.
And they found that, even with
the classic symptoms present,
that even as low as 100 colony-forming units per milliliter,
can be suggestive and diagnostic for
UTI among otherwise healthy patients.
Kind of remarkable.
Much lower threshold than there was in the past when
it had to be 105 CFU per milliliter in order to diagnose UTI.
In terms of management, we reach to antibiotics.
And I can tell you there is not one that's perfect.
First line is still considered trimethoprim sulfamethoxazole
but usually three days is acceptable.
Try to think about what your rates of resistance
are when you're getting cultures back.
If your rates of resistance to TMP-SMX exceed 20%,
in my practice, they probably see 30 to 40%,
it’s probably better to reach for another drug.
The one I usually reach for, nitrofurantoin,
it's an older drug, but associated
with lower rate of resistance.
Unfortunately, multiple times per day dosing
and you have to take it for five days,
but generally well tolerated and more effective.
And then fosfomycin is also an option,
and that's just one dose for a very
convenient type of dosing schedule.
Second line agents include
fluoroquinolones which are effective,
but we are trying to practice stewardship
and avoid overuse of fluoroquinolones
and avoid the spread of fluoroquinolone resistance.
So, let’s talk about UTI in kids because
this is an issue that comes up in practice,
but also very much will come
up on your examination.
So, first of all, abnormal urinalysis,
so with white cells or nitrite,
leukocyte esterase, plus at least
50,000 colony-forming units per milliliter.
Now, for kids, it's a special case.
You want to look for congenital abnormalities
of the renal and bladder system.
So, therefore, doing an ultrasound on those organs is important
even after a first UTI between 2 and 24 months of age.
what was also recommended in the past
was avoiding cystourethrogram.
That's no longer recommended.
So, I think that might be the exam
question you get is, what is indicated.
So, culture would be indicated.
Urinalysis would be indicated.
Ultrasound would be indicated.
VCUG would not be indicated for first UTI
in cases of between 2 and 24 months.
Second UTI, yes, it would be.
Checking for reflux.
So, in terms of management of
UTI among young children,
oral antibiotics are acceptable.
They don’t have to be put in the hospital.
Previously, everybody required parenteral antibiotics.
So, IV only if they're really sick,
but it is a longer duration of treatment.
It’s between 7 to 14 days, depends on the practitioner.
But it’s not – no three or five-day
options are available for children.
So, that's a brief overview of urinary tract infection.
A common diagnosis.
We may kind of take for granted,
but hopefully you’ve gained a few pearls
there in terms of clinical wisdom that
it may be able to be manage on
the phone in those classic cases.
You got some insight into antibiotics.
And particularly the workup in kids.
Those are all good things to know for
your exam and for your clinical practice as well.
Thanks very much.