Excuse me!
BMJ 2007; 335 doi: https://doi.org/10.1136/bmj.39422.578970.DE (Published 20 December 2007) Cite this as: BMJ 2007;335:1293
- J Granville-Chapman,
- R L Dunne
- jgchapman{at}doctors.org.uk
Sneezing etiquette and the efficacy of masks in the operating theatre remain a subject of debate.1 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⇓ shows the droplet spray from a sneeze without a mask. Fig 2⇓ shows slight droplet spray escaping from the sides of the mask. Fig 3⇓ 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.
Fig 1 Sneeze without a surgical mask: lateral view
Fig 2 Sneeze with a surgical mask: posterior view
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.
Footnotes
Competing interests: None declared.