Nothing To Sneeze At! A Study Into Intra-Operative Contamination

Purpose: We performed a prospective study of sneezes from orthopaedic registrars to assess the potential for intra-operative contamination from a masked surgeon, and to determine if head position can alter the potential for contamination.Type of Study: Prospective controlled trial.Methods: Four orthopaedic registrars from the Gold Coast Hospital each inhaled pepper to precipitate a sneeze. Cultures were taken with and without standard Smith & Nephew T surgical masks, in positions directly in front and to the sides of a masked registrar. The process was repeated three times for each registrar. A control plate was left exposed to the atmosphere. A control plate and sneeze plate was cultured on blood agar. Three masks were subsequently swabbed to exclude contamination from the masks.Results: 2/24 (8.33%) of the side with mask cultures returned significant bacterial growths. Also, 1/12 (8.33%) of the front with mask cultures returned significant growths. In addition, 9/12 (75%) of the direct sneezes resulted in significant bacterial counts. The control plate failed to return any growth. Subsequent culture of the exterior of three surgical masks failed to yield significant growth. There was a statistically significant odds ratio of 0.03 comparing the front and side group with the unmasked direct group. There was no statistically significant difference comparing front and side sneeze growth.Conclusions: While the use of surgical face masks significantly reduces bacterial counts following a sneeze, it fails to eliminate the potential for surgical field contamination completely. The fact that significant bacterial counts can be returned from direct culture through a mask and to the sides of a mask suggests that head position is irrelevant and contamination is possible in any direction. It is, therefore, suggested that, if possible, a sneezing surgeon distances himself/herself as much as possible from the sterile field. We also recommend following a sneeze; surgeons should re-gown and glove, given the risk of contamination of the sterile field.