BMJ  2007;335:1293 (22 December), doi:10.1136/bmj.39422.578970.DE

Mixed messages

Excuse me!

¹ Department of Plastic Surgery, Salisbury District Hospital, Salisbury

J Granville-Chapman and R L Dunne review the etiquette of sneezing in surgical masks

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.

View larger version (79K): [in this window] [in a new window] [PowerPoint Slide for Teaching]   Fig 1 Sneeze without a surgical mask: lateral view

 

View larger version (51K): [in this window] [in a new window] [PowerPoint Slide for Teaching]   Fig 2 Sneeze with a surgical mask: posterior view

 

View larger version (42K): [in this window] [in a new window] [PowerPoint Slide for Teaching]   Fig 3 Sneeze with a surgical mask: lateral 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.

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Competing interests: None declared.

References

1. Romney MG. Surgical face masks in the operating theatre: re-examining the evidence. J Hosp Infect 2001;47:251-6.[CrossRef][ISI][Medline]

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Rapid Responses:

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Thanks for clearing that up!

Ilyas Arshad
bmj.com, 30 Dec 2007 [Full text]

Why sneeze?

Chris M Heward
bmj.com, 30 Dec 2007 [Full text]