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DR. CORDOVER: Dr. Fox, we'd
like your guidance in diagnosing and treating a couple
of typical examples of patients we often see in the Emergency
Department. First, an 81-year-old man came into my ED
with intermittent fevers reported by his nursing home.
He is on dialysis but has not been in the hospital for
more than six months. His urine is clean, but his white
count is over 14,000. I cannot find a clear source. Is
there an occult MRSA bacteremia? What would you do with
this fellow?
DR. FOX: This is
a tough patient. We have someone presenting from a nursing
home who does not have a clear source for his fever and has
an elevated white blood cell count. Under most circumstances,
the differential diagnosis of this would be relatively broad,
including lower respiratory tract, urine, and bloodstream related
infections. However, since the patient is on dialysis and has
potential frequent manipulation of a line, the possibility
of occult methicillin resistant Staphylococcus should be higher
on your list for this particular patient. Hence, I would be
very concerned about the possibility of occult MRSA bacteremia
in a dialysis patient. After obtaining blood cultures in this
patient, I would strongly consider giving a dose of an intravenous
antibiotic while the cultures were waiting. Ultimately, the
decision whether to admit the patient to the hospital or to
send the patient back to the long-term care facility with the
cultures incubating will have to be a clinical decision but
in this particular patient who’s on dialysis, I would
have extra heightened concern about methicillin-resistant Staph
bacteremia.
* * * * * * * * * * * *
DR. CORDOVER: Second, a morbidly
obese type II diabetic woman came in to our ED with malaise,
low-grade fever and a painful, spreading, irregular flat
area of redness and warmth over her right lower leg. My
colleague called it cellulitis, treated her with cefazolin
and admitted her. Given the recent change in MRSA prevalence,
should we be treating this kind of infection differently?
DR. FOX: I believe
that this also is a patient of concern for someone at risk
for methicillin resistant Staph. Again, as we discussed earlier
in the presentation, we’d have to look at the risk factors
for this patient for the acquisition of community-associated
MRSA. Patients that are diabetics are certainly more prone
to Staphylococcal colonization and may have a slightly higher
frequency of community-associated MRSA. There’s also
concern about the penetration of antibiotics into this morbidly
obese patient and specifically into the area of the leg and
cellulitis. Beta-lactam drugs do have excellent penetration
into tissues but they generally will need to be given in higher
doses. For example, 2 grams of cefazolin every 8 hours, then
a smaller dose of cefazolin. If we’re going to choose
an agent for methicillin-resistant Staph, there are some limitations
for vancomycin for penetration into skin and soft tissues,
particularly for a morbidly obese patient. Hence, the administration
of a couple of the newer anti-infective agents such as daptomycin
or linezolid should be considered for this patient.
I would say that it’s generally
not good practice to second-guess your colleagues. However,
if presented with this particular circumstance, I would be
cautious that there’s not methicillin resistant Staph
and hence I would certainly consider discussing with the admitting
physicians the possibility of methicillinresistant Staph in
this particular occasion.
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