Thursday, January 31, 2008
The previous post, on OR sterility, occasioned an email from a professor of surgery, who informed me of a study of which I hadn't been aware. I quote from his letter:
"I wanted to draw your attention to another surgical/OR dogma that has essentially been put to rest, the wearing of the surgical mask. The Karolinska Institute (and other groups) has evaluated wound infections in two groups, one in which the OR team wore surgical masks, the other without masks. The outcome, as you might predict, was that the infection rates are the same (4.7% with vs. 3.5% without). Here is one of the references: World J Surg. 1991 May-Jun;15(3):383-7; discussion 387-8."
Whereas, in this litigious society, I doubt you'll see anytime soon surgeons and scrub personnel eschewing their masks as a result of this study, I find it unsurprising; not to mention amusing and validating. Part of the inference to be drawn from my previous post is that some of what we do is not much more than ritual -- or, at least, it's unproven even if it makes intuitive sense.
In my earlier days, the ten-minute scrub (washing hands and arms before donning gloves and gown) was standard. So much so, that many ORs had timers above the sinks. Having never seen any studies comparing ten minutes with, oh, eight, or six, I can say I never scrubbed that long, unless someone was breathing down my neck. Later, studies were done: I was right.
Reading the email, I was reminded of a sort-of secret about my practice. For reasons of cost-saving, simplicity, and patient convenience, I did countless breast biopsies in my office, under local anesthesia. These were full-fledged surgical biopsies, not needle sampling (which I also did, in far greater numbers.) I had a small procedure room with a small OR table, a cautery unit (which I rarely used, preferring -- for cost saving, mostly -- the old fashioned suturing of bleeders), and I used instrument packs that we made up and cooked in an autoclave (eventually, after we built a surgery center in our building, we had them process the instruments.) Anyhow, my point is this: I painted the skin with antiseptic, used a small sterile drape, wore gloves and a clean cotton frock, short-sleeved and the size of a shirt. And no mask, unless I had a cold. I'm certain if some credentialing agency were to observe, I'd have been hauled off and boiled in oil. Yet, over a period of twenty-plus years, I never had a wound infection. Got a few hematomata, I'll admit, which I either drained or left alone, depending. But no infections.
I'm not -- repeat: NOT -- suggesting that sterile precautions are unnecessary. Quite the opposite; but I intuit there may well be a level of caution beyond which some measures are less important than we think. (As I said in the previous post, the extraordinary care taken in certain settings is vital.)
A related concept: skin prep. Sterilizing skin before operating is essential. But there are some parts of the process that have always amused me. To wit: it's expected that a reasonable zone of prepped skin will surround the area to be incised. Absolutely necessary and proper -- probably the most important of all the things we do. Yet I've watched with consternation as the prep is done for, say, an inguinal hernia. Unfailingly, the prep is carried all the way to the ribcage or beyond to the north, but only a couple of inches below the groin, where the actual incision will be. Similarly, unless I intervened, the prep for an upper abdominal incision went way down to the pubis or below, but only just above the xiphoid process, topside. I'm not aware (the cop-out that says I haven't looked it up) of studies that compare skin prep distances from incision. I'd guess there is a minimum necessary distance, and a point at the other end of the spectrum beyond which it doesn't matter (taking account of the possible need to extend or make a second incision.)
So what's the lesson? Nothing very important. It just happens to interest me that whereas it's best to err on the side of caution, it seems that much of what we do isn't necessarily grounded in science, nor makes sense. Does that surprise anyone?