Preventing Surgical Site Infections (SSIs) After Surgery

The information in this column is intended fortrial, there was a 58 percent overall reduction in the
informational purposes only, and does not constituterelative risk of SSIs among the "experimental group"
medical advice or recommendations by the author.of patients when compared to the patients who
Please consult with your physician before making anyreceived only placebo ointment and placebo soap.
lifestyle or medication changes, or if you have anyThe benefit of preoperative treatment with
other concerns regarding your health.mupirocin ointment and chlorhexidine soap was even
Infections following surgery in the United Statesmore pronounced for SSIs involving deep body
occur in approximately 3 to 5percent of all cases, andspaces, in this study: the relative risk of deep body
in more than 10 percent of certain types ofspace SSIs was reduced by 79 percent in the
operations. In view of these statistics, surgical site"experimental group" of patients. Therefore, the
infections (SSIs) are a major public health problemresults of this powerful prospective clinical trial
throughout the world. On average, patients in thesuggest that SSIs following elective surgery can be
United States who develop an SSI will remain in thesignificantly reduced by, first, testing patients for
hospital for an additional week, resulting in an averageevidence of colonization with Staphylococcus aureus
of more than $25,000 in additional healthcare costsbacteria and, secondly, by "decolonizing" the nasal
per affected patient. Patients who develop SSIs arepassages and skin of already-colonized patients with
also 60 percent more likely to be admitted to theantibacterial ointment and soap, respectively.
ICU, and are twice as likely to die, when comparedMany hospitals already selectively apply nasal cavity
to patients who do not develop SSIs followingtesting for MRSA (either before or following surgery),
surgery. Moreover, at a time when profound changesand recommend a shower with chlorhexidine soap
in the United State's health care system are beingprior to surgery. The results of this important public
proposed to control skyrocketing health care costs,health study suggest that the incidence of SSIs can
SSIs are estimated to add an additional $10 billion inprobably be further lowered by more rigorous and
national health care costs, annually. In addition to themore universal preoperative screening programs for
economic costs associated with SSIs, seriousnasal Staphylococcus aureus (including both MRSA
infections following surgery often cause considerableand non-MRSA Staphylococcus aureus) directed at all
suffering among affected patients; and in severepatients who are undergoing elective surgery.
cases, SSIs can also result in permanent disability orThe second, and related, study evaluated the impact
death.of two different preoperative skin prep solutions on
The known causes of SSIs are complex and multiplethe incidence of SSIs.
and, therefore, no single or simple solution is capableFor decades, now, iodine-based skin cleansing
of eliminating all cases of SSIs. However, there issolutions have been applied to skin surfaces just prior
ample research data available suggesting that ato the start of surgery, in an effort to kill
number of opportunities exist whereby the risk ofskin-surface bacteria that can lead to SSIs. While
SSIs can be further reduced. For example, one majorthese traditional iodine-based antibacterial skin prep
(and preventable) cause of potentially life-threateningsolutions are active against many bacteria and fungi
SSIs is the increasing prevalence of antibiotic-resistantthat are known to cause SSIs, their antibacterial and
strains of bacteria that have developed followingantifungal activity rapidly dissipates after being applied.
decades of excessive and inappropriate antibiotic use.Newer surgical skin prep agents that contain alcohol
Among these resistant bacteria, few have raisedand chlorhexidine have been shown by recent
more concern than methicillin-resistant Staphylococcusresearch studies to not only have a wider spectrum
aureus (more commonly known by its acronym,of activity against skin bacteria and fungi than
MRSA). MRSA is capable of causing limb- andtraditional iodine-based prep solutions, but these
life-threatening infections, particularly in very illnewer surgical prep solutions also sustain their
patients, and in the very young and very old. When Iantibacterial and antifungal activity over a much
began my medical career, more than 20 years ago,longer duration than their iodine-based counterparts.
MRSA was an exceedingly rare cause of bacterialIn this new prospective, randomized clinical research
infections. When MRSA first began to appear, thisstudy, 849 patients undergoing elective surgery were
bacterium primarily caused infections among seriouslyrandomized to one of two groups. One group of
ill hospitalized patients, and was rarely a source ofpatient volunteers underwent preoperative skin
infection among generally healthy nonhospitalizedpreparation with a commercially available
patients.chlorhexidine-alcohol solution, while the second group
In a landmark study by the Centers for Diseasewas randomized to undergo skin preparation with the
Control, and published in the Journal of the Americantraditional povidone-iodine solution.
Medical Association in 2007, a remarkable 58 percentFollowing surgery, 16 percent of the patients who
of invasive infections caused by MRSA in 2004 andhad their skin prepped with povidone-iodine solution
2005 occurred in nonhospitalized patients, while 27developed SSIs within 30 days of surgery, while just
percent of MRSA infections arose among hospitalizedunder 10 percent of the patients who received the
patients. This tectonic shift in the epidemiology ofchlorhexidine-alcohol skin prep solution subsequently
MRSA (and other emerging strains ofdeveloped SSIs. (This 41 percent reduction in the
antibiotic-resistant bacteria and fungi, as well) hasrelative risk of SSIs was found to be highly
grave implications for preventing SSIs, as thestatistically significant.) Although use of the
majority of SSIs are known to arise from the surgicalchlorhexidine-alcohol skin prep, alone, did not appear
patient's own native bacteria.to protect against deep organ-space infections (when
Two important new studies related to SSIcompared with the use of povidone-iodine skin prep
prevention, and just published in The New Englandsolutions) in this study, both superficial and deep SSIs
Journal of Medicine, offer important new ammunitionof the surgical incision were significantly reduced
in the ongoing fight against potentially deadly SSIs.following use of the chlorhexidine-alcohol skin prep
In the first study, from the Netherlands, patientssolution. In this study, the use of a
being admitted to the hospital for elective surgerychlorhexidine-alcohol prep solution cut the risk of
were tested for the presence of Staphylococcussuperficial incisional infection by one-half, while deep
aureus bacteria in their nasal passages. In thisincisional infections were reduced threefold. Thus, the
prospective, randomized, placebo-controlled,use of chlorhexidine-alcohol skin prep solutions, just
double-blind, multi-center clinical research trial, 6,771prior to making the incision, was associated with a
patients were screened for the presence of nasalhighly significant reduction in the incidence of both
Staphylococcus aureus, and 1,251 of these patientssuperficial and deep infections of surgical incisions
were confirmed to be nasal carriers of this bacterium.when compared to traditional iodine-based prep
A total of 917 of these patients were subsequentlysolutions.
enrolled into this clinical research trial. These 917Taken together, these two very important
patients were then divided into an "experimental"prospective randomized clinical research trials offer
group and a "control" group, although neither theclinically valuable lessons for patients, physicians, and
patients nor the research assistants in thishospitals in our crucial quest to drive down the
double-blind study were permitted to know whichincidence of SSIs to the lowest achievable level. In
group any patient was assigned to until after theview of the recent and ongoing emergence of highly
study had been completed. Patients randomized tovirulent strains of bacteria and fungi that have
the "experimental" group were treated, beforebecome resistant to many of our most powerful
surgery, with antibacterial ointment (mupirocin) appliedantibiotic and antifungal drugs, respectively, it is
to their nasal passages, and with showers usingimperative that we find new ways to reduce the risk
antibacterial soap (chlorhexidine), in an effort toof SSIs, and particularly new methods that do not
eradicate surface bacteria (including Staphylococcusinvolve the continued inappropriate or excessive
aureus) from their noses and skin. The "controlutilization of broad spectrum antibiotic drugs.
group" of patients received identical-appearing nasalIf you are scheduled to undergo elective surgery in
ointment and skin soap, but without mupirocin orthe near future, I would advocate that you share the
chlorhexidine.findings of these two clinically important research
All study patients were tracked following surgery,studies with your surgeon (if they are not already
and the incidence of SSIs was then analyzed. In thisaware of them).
highly-powered randomized, controlled clinical research