Wednesday, October 15, 2008

Rub a Dub Dub

Quite a bit of attention has been paid to the prevention of surgical site infections over the past few years --- and this is one area that CMS/Medicare is targeting in its ever expanding "never event" list (I have ranted a bit about this before). From the CMS web site detailing a July 31, 2008 press release:

In last year’s final rule, CMS listed eight preventable conditions for which it would not make additional payments. In this year’s proposed rule, CMS identified nine potential categories of conditions, but based on public comments, is finalizing three of these. The new additional conditions in this year’s final rule include:
  • Surgical site infections following certain elective procedures, including certain orthopedic surgeries, and bariatric surgery for obesity
  • Certain manifestations of poor control of blood sugar levels
  • Deep vein thrombosis or pulmonary embolism following total knee replacement and hip replacement procedures
    Simply put, we strive to ensure that each patient presenting for an elective operation has the lowest possible risk of developing a surgical site infection. There are a whole host of factors which contribute to the risk of a wound infection, many of which are out of the physician and hospital's control --- obesity, diabetes, etc. Some, however, are well within our purview, such as appropriate use of perioperative antibiotics, proper prepping and draping, etc. One idea that was previously en vogue, but which has fallen out of favor in recent years is the preoperative shower.

    NO. That does not mean that the surgical staff takes a group rinse-off on a Slip 'N Slide just prior to operating. It means that the patient takes a shower using an antimicrobial soap before coming to the hospital. In the good old days, when patients came to the hospital on the night before surgery, this was de rigeur. I know, the whole idea of sitting around in a hospital room, idly awaiting surgery the next day, seems like something straight out of the Farmer's Almanac, but it did indeed happen that way just a few short years ago.

    Those of you paying attention are probably thinking, "What a load of ACORN voter registrations crap! Taking a shower, at home, then putting on your regular clothes and having surgery a couple of hours later? No way will that decrease your risk of a wound infection." To you I would say "Thank you for paying attention. But, au contraire, you are mistaken." The reason the preoperative shower is supposed to work is because we ask patients to use an antimicrobial soap, which has been shown to decrease skin bacterial count even after a few hours in normal clothing.

    This practice was already waning to some degree when a collective review sort of put a stake through its heart:
    Six trials involving a total of 10,007 participants were included. Three of the included trials had three comparison groups. The antiseptic used in all trials was 4% chlorhexidine gluconate (Hibiscrub). Three trials involving 7691 participants compared chlorhexidine with a placebo. Bathing with chlorhexidine compared with a placebo did not result in a statistically significant reduction in SSIs; the relative risk of SSI (RR) was 0.91 (95% confidence interval (CI) 0.80 to 1.04). When only trials of high quality were included in this comparison, the RR of SSI was 0.95 (95%CI 0.82 to 1.10). Three trials of 1443 participants compared bar soap with chlorhexidine; when combined there was no difference in the risk of SSIs (RR 1.02, 95% CI 0.57 to 1.84). Two trials of 1092 patients compared bathing with chlorhexidine with no washing, one large study found a statistically significant difference in favour of bathing with chlorhexidine (RR 0.36, 95%CI 0.17 to 0.79). The second smaller study found no difference between patients who washed with chlorhexidine and those who did not wash preoperatively.

    This review provides no clear evidence of benefit for preoperative showering or bathing with chlorhexidine over other wash products, to reduce surgical site infection. Efforts to reduce the incidence of nosocomial surgical site infection should focus on interventions where effect has been demonstrated.
    Hmmm. That's a lot of data that doesn't push the preop shower agenda, but it goes against a raft of non-clinical data showing a decrease in bacterial count when a preop shower is utilized. As CMS is pushing with vigor to avoid paying for surgical site infection complications, perhaps another look at this is worthwhile. Sure enough, a study was published in the August edition of the Journal of the ACS entitled Preoperative Shower Revisited: Can High Topical Antiseptic Levels Be Achieved on the Skin Surface Before Surgical Admission? These authors compared liquid 4% chlorhexidine gluconate (CHG) and a pre-made cloth containing 2% CHG; three groups were studied [1] evening shower alone; [2] mornign shower alone; and [3] morning and evening shower (each group was subdivided into use of each of the two forms of CHG). From the abstract, we learn:
    Effective CHG levels were achieved on most skin sites after using 4% CHG; gaps in antiseptic coverage were noted at selective sites even after repeated application. Use of the 2% CHG polyester cloth resulted in considerably higher skin concentrations with no gaps in antiseptic coverage. Effective decolonization of the skin before hospital admission can play an important role in reducing risk of surgical site infections.
    OK, again for those paying attention ---- didn't the first review we talked about conclude that there was no clinical difference when a preop shower was used or not? Why, yes! So, what have we learned with this new study? Unfortunately, nothing that we can state is clinically useful, because this study did not enter the real world of clinical results.

    So, that sort of begs the, why do this kind of study in the first place? The answer may just be in the disclosure at the bottom of the article:
    Disclosure Information: The following disclosure has been reported by the author: Dr Edmiston received an unrestricted research grant as an investigator for Sage Products, Inc. No one derived personal compensation from this grant. The grant was used, in part, to purchase supplies such as the 4% CHG and the 2% CHG cloths along with other material used in the study. These monies were also used to support other research activities in the laboratory that are not related to any skin-prepping product.
    Who is Sage Products? They make these things:
    OK. I am not finger-pointing here. Really. In fact, I am on record as being supportive of industry-sponsored medical research. I think that in the long run, it is a good thing, and certainly more cost-effective and less subject to political winds than government-sponsored research. But let's be brutally honest --- a study like this that gives us essentially no new information, but which throws the possibility of clinical relevance into its title and discussion is really not helping anybody.

    "OK, Mr. Smarty Pants," you may say, "what can the average patient who is scheduled for surgery, or the average surgeon, make of this study?" Even with the reservations I spoke of, and even with the multi-study review stating otherwise, I have a hard time arguing against the idea of a preop shower with an antimicrobial soap or cloth --- because with the "never event" harassment hanging over us, hospitals and physicians may have to start producing reams of proof that they have done everything in their power to prevent a surgical site infection. Even if there is no data to support it.

    Want some of your own CHG cloths for your upcoming surgery? I've done the research for you -- Walgreens is cheaper than Wal-Mart.