Surgical Helmet Systems and Intraoperative Wound Contamination

Abstract

Objective:The original Charnley-type negative-pressure body-exhaust suit reduced infection rates in early trials of total joint arthroplasty. However, recent registry data on modern positive-pressure surgical helmet systems (SHS) have not shown this benefit, and have instead suggested a paradoxical increase in infection rates with SHS use. The gown-glove interface has been identified as a potential source of particle contamination. The aim of this study was to compare wound contamination in total knee arthroplasty (TKA) between conventional surgeon attire and SHS with and without protective tape at the gown/glove interface.Methods:75 patients undergoing TKA were randomised into three groups: in group one the scrubbed theatre staff wore conventional surgical attire, in group two SHS without tape, and in group three SHS with tape sealing the gown-glove interface. All TKA operations were carried out in a standardised manner by a single surgeon. Bacterial contamination was assessed using both a culture-based tetrazolium stained membrane imprint technique (TSMI) technique (See Figure 1) and detection of bacterial ribosomal DNA using polymerase chain reaction (PCR). For PCR two tissue samples were taken at the beginning of the operation to act as controls and five at the end of the first hour. For culture a tetrazolium stained membrane imprint technique was used with membranes pressed onto the wound at the time of tissue sampling.Results:For TSMI culture, with a conventional attire 0/25 of the patients had a positive culture, with SHS and no tape 1/26, and with SHS and tape 4/24. Differences in measured contamination did not differ between groups (chi square test conventional gown (0/25) vs SHS (5/50) p= 0.16, SHS without tape (1/26) to SHS with tape (4/24) p = 0.18 (See Table 1).Conclusions:Overall contamination rates were low in all groups. No difference was seen in wound contamination between conventional attire and SHS. The use of tape at the gown glove interface with SHS did not appear to reduce contamination rates.