BehindTheMedspeak: When a surgeon sneezes

Steve Mirsky's February, 2008 Scientific American article deconstructed a study that appeared in the 2007 year-end issue of the British Medical Journal.

Here's what Mirsky had to say about sneezing surgeons.
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Nothing to Sneeze At

It’s a problem faced by Yogi Berra, welders and surgeons: How do you sneeze with a mask covering your face? Catchers and welders, however, only have to deal with the unpleasant bounce-back effect. Surgeons need to worry about ejecting multitudinous microbes directly into the gaping hole they’ve carved in a patient. Not good. And with “uh-oh” being among the worst words a surgeon can say at work (“Where’s my watch?” is also bad, as is the simple and direct “oops”), how best then to avoid an uh-oh following an achoo?

The answer to this and other pressing questions in science and medicine can be found in the year-end issue of the British Medical Journal, well known for its unusual array of offbeat articles. (Had the Puritans never left Britain for New England, they might later have fled the British Medical Journal to found the New England Journal of Medicine.)

First, the case of the surgical sneeze. The accepted wisdom was that the surgeon should in fact sneeze facing the area being operated on — because the mask will redirect the ejecta and send it backward out of the sides of the mask, away from the open wound. But two plastic surgeons from a British hospital checked the literature and found no actual evidence that the masked sneeze did in fact fling the phlegm sideways. They thus phlegmatically set out to test the hypothesis, using high-speed photography and some finely ground pepper to encourage sneezing by masked volunteers.

The result: very little of the blast escapes out the sides, and a bit sneaks out of the bottom, onto the surgeon’s upper chest. Most of the debris appears to stay safely within the doctor’s domain, leaving the patient pristine. Unable to offer any clear direction to surgeons, the authors offer these clear directions:

“Surgeons should follow their instincts when sneezing during operations.” One might call such instruction the gesundheit of reason.

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Now you're all warmed up and ready for the real thing, so here's the original article as published in the British Medical Journal on December 22, 2007.
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Excuse me!

Sneezing etiquette and the efficacy of masks in the operating theatre remain a subject of debate. Standard teaching dictates that one must face the wound when sneezing, so that droplets escape backwards, via the sides of the mask. A literature search found no clear demonstration of this principle.

We therefore tested the hypothesis that one should face the wound when sneezing into a surgical mask in theatre.

Method: A surgeon wearing a surgical mask (Kimberley Clark Healthcare) was encouraged to sneeze by inhaling finely ground pepper. A small reservoir of water was held in the floor of the mouth to improve the appearance of the droplets on the photographs. All photographs were taken by the medical photography department in a dark room with a dark background, using a Kodak DCS Pro SLR camera (ISO 160, 13.5MP resolution, RAW format) and a Nikon Micro-Nikkor 55mm F2.8 lens. A Sony HVL56AM flashgun was strobed (1/32 power, 2 sec, 10Hz). Images were converted into TIFF files and then sharpened slightly on Adobe Photoshop.

Results: Fig 1 [top] shows the droplet spray from a sneeze without a mask. Fig 2 [below]



shows slight droplet spray escaping from the sides of the mask. Fig 3 [bottom] shows there is also little spray escaping anteriorly. On close inspection, however, a few droplets can be seen escaping inferiorly on to the surgeon’s upper chest. None of our photographs showed substantial numbers of droplets passing behind the head of the surgeon.



Discussion: The doctrine of facing the wound when sneezing seems logical. Our study does not, however, support this hypothesis. A few droplets of spray escaped sideways, but no substantial numbers passed behind the surgeon’s head. Our photographs show that the most important visible escape of spray comes from below the mask on to the surgeon’s chest. We therefore recommend that surgeons should follow their instincts when sneezing during operations.