Editor’s Spotlight/Take 5: Vancomycin Prophylaxis for Total Joint Arthroplasty: Incorrectly Dosed and Has a Higher Rate of Periprosthetic Infection Than Cefazolin
Editor's Spotlight/Take 5
M. Daniel Wongworawat
-
eight-based dosing of
medications is not a
foreign concept to most of us.
We learned it in medical school,
especially while rotating on the
pediatrics service. We did it while in
residency, ordering weight-based
gentamicin for certain open fractures [10].
And when we order antibiotics for
A note from the Editor-In-Chief:
In ‘‘Editor’s Spotlight,’’ one of our editors
provides brief commentary on a paper we
believe is especially important and worthy of
general interest. Following the explanation of
our choice, we present ‘‘Take Five,’’ in which
the editor goes behind the discovery with a
one-on-one interview with an author of the
article featured in ‘‘Editor’s Spotlight.’’
The author certifies that neither he, nor any
members of his immediate family, have any
commercial associations (such as
consultancies, stock ownership, equity
interest, patent/licensing arrangements, etc.)
that might pose a conflict of interest in
connection with the submitted article.
All ICMJE Conflict of Interest Forms for
authors and Clinical Orthopaedics and
Related Research1 editors and board
members are on file with the publication and
can be viewed on request.
treatment, we sometimes adjust the
dose to ensure therapeutic dosing. But
for prophylactic antibiotics before
surgery, somehow the fixed 1-g dose
has become common practice. Most
patients receive a 1-g dose of
cefazolin, and for those patients with a
beta-lactam allergy, 1-g dose of
vancomycin is sometimes substituted. But
patients come in different sizes.
There is good evidence suggesting
that failing to recognize this may
increase the risk of prosthetic joint
infection (PJI). A recent study [21]
looking at trabecular bone harvested
from patients who underwent TKA
demonstrated that vancomycin levels
in bone varied with BMI, where higher
concentrations were seen in patients
with lower BMI. Additionally, the
study points to the pharmacokinetic
properties of vancomycin, where it has
greater deposition in soft tissues when
compared to cefazolin; therefore, a
smaller proportion of vancomycin is
available in trabecular bone. Surgeons
may use vancomycin for prophylaxis
in patients colonized with
methicillinresistant Staphylococcus aureus
(MRSA), and this practice may
become more widespread as the
prevalence of MRSA infection is
increasing [9, 19]. However, we
sometimes use vancomycin for
patients with a history of penicillin
allergy, a practice that perhaps should
be abandoned. There is, in fact, little
risk that a patient with a reported
allergy to penicillin will experience
anaphylaxis when given cefazolin [3,
14].
The question we are most
concerned about, though, is whether
patients are adequately dosed with
whatever antibiotic they do receive,
and whether those who are underdosed
are more likely to develop PJI, which
is a dreaded complication. In this
context, the work of Dr. Kheir and his
team from Thomas Jefferson
University in Philadelphia, PA, USA should
matter to all orthopaedic surgeons.
They found that among primary TJAs,
patients receiving vancomycin had a
higher rate of PJI compared with
patients receiving cefazolin
prophylaxis, and that the majority of patients
given vancomycin prophylaxis were
underdosed based on the weight-based
dosage recommendations. In a
glimmer of bright news, MRSA did not
occur in patients who were adequately
dosed with vancomycin. In addition to
adequate dosing, this paper gives us an
important reminder that surgeons
should use vancomycin judiciously
and rarely as a sole agent. Please join
me for the Take-5 interview with Dr.
Michael M. Kheir, as we dig deeper
into this critically important clinical
problem.
Take-5 Interview with Michael M.
Kheir MD, primary author of
‘‘Vancomycin Prophylaxis for Total
Joint Arthroplasty: Incorrectly
Dosed and Has a Higher Rate of
Periprosthetic Infection Than
Cefazolin’’
M. Daniel Wongworawat MD: What
prompted your interest in looking at
compliance with vancomycin dosing
recommendations? Why did you think
there might be low
acceptance/implementation of the weight-based dosing
guidelines for vancomycin
administration?
Michael M. Kheir MD: As a large
institution, we have surgeons with
diverse practices—some who
administer vancomycin prophylaxis routinely,
and others only in light of
patientspecific factors such as being
MRSApositive or having a history of
anaphylaxis to penicillin. We were
interested in studying this because recent
guidelines have demonstrated that
vancomycin should be weight-based [2, 7],
yet many surgeons at our practice and
around the country are accustomed to a
fixed 1-g dose of vancomycin.
The low acceptance of
weightbased dosing guidelines may simply be
due to unawareness. The guidelines
were introduced in the last few years [2,
7], and although they are well-known
among infectious disease specialists,
orthopaedic surgeons and
anesthesiologists may be less familiar since they are
not traditionally trained to give
weightbased doses (...truncated)