|
DR. CORDOVER: We are being told that
community-associated MRSA infections are actually being
disseminated in hospitals and emergency departments.
If this is true, how prevalent is it, and aren’t
gloves and alcohol-based hand foams for surface cleaning
enough to prevent the transmission of community-associated
MRSA?
DR. FOX: This is a great question,
especially for health care workers. Let me try and tackle the
first portionof this question which I briefly alluded to before.
Surprisingly, about 50% of all the MRSA that is in hospitals
these days is actually coming in from the community. This is
held up in several studies and publications so far. The transmission
of MRSA is no different between the old hospital-associated
strain of MRSA and the community-associated strain. It is true
that we are adopting standard precautions which asks us to
wash our hands with running water and /or alcohol-based hand
gels before going to a patient room and after going to a patient
room, and in circumstances where there are wounds or incision-and-drainages
to be accomplished, to wear gloves. That does eliminate and
prevent a lot of transmission of community-associated MRSA.
MRSA is susceptible to the alcohol-based hand
gels and certainly if you wanted to wash your hands for 30
seconds or more, then you will be effective in reducing the
transmission of MRSA. There can be, as I alluded to earlier,
contaminated surfaces and you do have to be somewhat vigilant
of the contaminated surfaces. The standard hospital disinfectants
are effective for killing MRSA on environmental surfaces so
I believe it is important to have a protocol for patients seen
in the emergency department to have theirbed or their area
wiped down after the patient leaves that particular room or
particular area.
* * * * * * * * * * * *
DR. CORDOVER: How do I keep from bringing
this home with me? Can I bring MRSA home on my scrubs? Do
I need to be decolonized?
DR. FOX: There are some things
that you can do to prevent bringing this home with you. We’ve
already discussed using alcohol-based hand gels and wearing
gloves. I think we know that with the environment as a potential
source, if you bring scrubs home from your emergency department
visit, this does run the risk of bringing this organism into
your home. I would strongly encourage physicians not to wear
their work clothes home if they’re concerned about community-associated
MRSA. It would be ideal for them to change into scrubs, wear
the scrubs, and then have the scrubs laundered. It’s
fortunate that having laundry water temperatures greater than
180 degrees is effective in killing resistant Staphylococcus
and hence we can trust that laundering scrubs is effective.
I would also advise that emergency department
physicians certainly do a good hand washing before they leave
their shift. Some of you may feel compelled to take a full
shower when you leave or when you get home. This is not unreasonable.
There are some disinfectant soaps that can be used to reduce
your risk of community-associated MRSA and the disinfectant
soaps also are occasionally used by infectious disease and
other healthcare providers for decolonization regimens. These
antimicrobial soaps are Phisohex-based soaps or chlorhexidine
2%-based soaps, or much less likely, betadine-based soaps.
Now, if you’re going to shower or lather
with these once a week or twice a week, there is a trick that
one needs to know for using these antimicrobial soaps, and
this is something that really is not taught very well in journal
articles. In order for disinfectant soaps to work, they have
to stay in contact with the skin surface for 3 to 5 minutes.
You’re all familiar with doing a preparation for surgery
and we try very hard to allow the betadine or the chlorhexidine
product to dry before inserting any scalpel or any needle.
The same is really true when applying chlorhexidine or Phisohex
to the skin. I generally recommend that people shower, get
themselves wet, and then apply the antimicrobial soap over
their body. I ask people to turn the water off or to go out
of the main stream of the water and to count to 200, or 180
for 3 minutes, and then to rinse. It is that contact time that
allows the antimicrobial soap to be effective. Too often, if
people do use antimicrobial soaps, they will just rub-a-dub-dub,
scrub it on and wash it right off, and that is defeating the
purpose of using an antimicrobial soap.
* * * * * * * * * * * *
DR. CORDOVER: It is quite common to see
recently hospitalized or nursing home patients come into
the ED with fever, confusion or other signs of infection.
Are there risk factors that would lead us to suspect HA-MRSA
infection as opposed to Pneumococcus, E. coli or Pseudomonas?
DR. FOX: This is an excellent
general question. It is important to note that any patient
that resides in a long term health care facility is at risk
for hospital-associated resistant Staphylococcal infections
and the presence of multi-drug resistant bacteria. So in general
our approach to treatment with anti-infective therapy is different
than the approach to patients that would present from the community.
If you believe the patient has a hospital and health care associated
infection, we’re more likely to empirically cover for
resistant gram negative bacteria and for hospital-associated
methicillin-resistant Staph. On the other hand, patients that
are coming from assisted living that are not in hospital situations
and are not frequently with health care providers, probably
do not fit into this category and can be treated more likely
as community-associated infections.
Methicillin-resistant Staph is also becoming
a factor in nursing home patients in decubitus ulcers in these
patients. We have to assume if a patient is living in a nursing
home, if they have a decubitus ulcer, and there’s a surrounding
area of cellulitis, that methicillin-resistant Staph is the
predominant organism. Some of these decubitus ulcers may be
polymicrobial. If they have been chronic and are on ischemic
limbs, there may be methicillin-resistant Staph, anaerobic
organisms, and some gram negative rods and even resistant gram
negative rods and you do have to factor these circumstances
when deciding on effective antimicrobial therapy. In patients
coming from nursing homes with decubitus ulcers, you certainly
should consider them as being at risk for having MRSA-based
infection and prescribe antibiotics accordingly.
DR. CORDOVER: What antibiotics
should we use to treat these patients? Should we start
anti-Staph drugs empirically?
DR. FOX: The antibiotics that
we previously mentioned for community-associated MRSA are not
the kind of antibiotics that we’re choosing for individuals
coming from extended care facilities or for patients that may
be seriously ill enough to require hospitalization. Under those
circumstances, we would generally utilize intravenous antibiotics.
The mainstay of intravenous therapy has been vancomycin for
the past 40 years. Until the early 2000’s this was the
only agent we had that was effective for methicillinresistant
Staphylococcus. We are fortunate now that there are a few new
anti-infective agents that are effective for Staphylococcus.
These include linezolid, daptomycin, and soon to be coming,
dalvabancin and telavancin, two glycopeptide antibiotics likely
to be approved by the Food and Drug Administration.
* * * * * * * * * * * *
DR. CORDOVER: How do you choose between
vancomycin and daptomycin and linezolid for treatment when
patients are admitted to the hospital?
DR. FOX: These are difficult
decisions and really require some degree of expertise and some
degree of assessment of the patient’s severity of illness.
I believe it’s beyond the scope of this particular CME
opportunity for me to go into the nuances of these various
drugs, but these are three agents that are available as choices
for us for treatment of hospital-associated patients.
One possible advantage of linezolid is the possibility
of an intravenous to oral step-down therapy for patients that
might have brief hospitalizations that would be discharged
on the same anti-infective agent. These agents may also be
considered for the treatment of patients in extended care facilities
without the need for patients to be hospitalized. It’s
very likely that the long-term care facility does have the
capacity to administer intravenous antibiotics in a once or
twice daily fashion. Many of these patients will also be elderly
and have elevated serum creatinine so that vancomycin may be
dosed on a once-aday basis instead of a twice-a day basis.
Certainly, patients presenting to the emergency
room who you think would need to be admitted to the hospital,
should ideally have blood cultures performed before antibiotic
agents are given. Indeed, the mortality of patients with presumed
sepsis from Staphylococcus and other organisms is dependent
in some degree on the timing and timely administration of anti
infective therapy. Recent critical care literature tells us
that for every hour of delay in the initiation of anti-infective
therapy for someone with a sepsis syndrome or sepsis, there
is an 8% increase in mortality. So it behooves us as emergency
department physicians to try to recognize sepsis cases in an
early fashion and subsequently administer antibiotics after
blood cultures have been drawn appropriately.
|
