Disposable surgical face masks for preventing surgical wound infection in clean surgery

Background

Surgeons and nurses performing clean surgery wear disposable face masks. The purpose of face masks is thought to be two-fold: to prevent the passage of germs from the surgeon's nose and mouth into the patient's wound and to protect the surgeon's face from sprays and splashes from the patient. Face masks are thought to make wound infections after surgery less likely. However, incorrectly worn masks may increase the likelihood of the wound getting contaminated with germs. We wanted to discover whether wearing a face mask during surgery makes infections of the wound more likely after the operation.

Review question

This review aimed to find out if wearing disposable face masks increases or decreases the number of cases of wound infection after clean surgery.

Study characteristics

We searched for all studies that had been done in the past relevant to this topic. Studies included in our analysis were those looking at the use of face masks in 'clean' surgery in adults and children. Clean surgery is when the operation does not go into organs that may contain bugs such as the lungs, gut, genitals and bladder. Infections of the wound are less likely to occur after 'clean' surgery, compared to 'unclean' surgery. We chose to look at this type of surgery because infections occurring after clean surgery would more likely be due to the use of the face mask, and not because of the nature of the operation. We also only looked at one particular type of study, the randomised controlled trial (RCT), where the people involved (participants) were randomly put into one of two groups: one group where the surgical team wore a face mask during the operation and one group where the surgical team did not wear a face mask. We compared the number of wound infection cases occurring after surgery between two groups.

Key results

Overall, we found very few studies and identified no new trials for this latest update. We analysed a total of 2106 participants from the three studies we found. All three studies showed that wearing a face mask during surgery neither increases nor decreases the number of wound infections occurring after surgery. We conclude that there is no clear evidence that wearing disposable face masks affects the likelihood of wound infections developing after surgery.

Quality of the evidence

The findings from this review cannot be generalised for several reasons: the studies included only looked at clean surgery, some of the studies did not specify what type of face mask was used and one of the studies did not involve many participants therefore making the findings less credible. The quality of the studies we found was low overall. The way in which participants were selected for the studies was not always completely random, which means the authors' judgements could have influenced the results. More research in this field is needed before making further conclusions about the use of face masks in surgery.

This plain language summary is up to date as of 22nd December 2015.

Authors' conclusions: 

From the limited results it is unclear whether the wearing of surgical face masks by members of the surgical team has any impact on surgical wound infection rates for patients undergoing clean surgery.

Read the full abstract...
Background: 

Surgical face masks were originally developed to contain and filter droplets containing microorganisms expelled from the mouth and nasopharynx of healthcare workers during surgery, thereby providing protection for the patient. However, there are several ways in which surgical face masks could potentially contribute to contamination of the surgical wound, e.g. by incorrect wear or by leaking air from the side of the mask due to poor string tension.

Objectives: 

To determine whether the wearing of disposable surgical face masks by the surgical team during clean surgery reduces postoperative surgical wound infection.

Search strategy: 

In December 2015, for this seventh update, we searched: The Cochrane Wounds Specialised Register; The Cochrane Central Register of Controlled Trials; Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE and EBSCO CINAHL. We also searched the bibliographies of all retrieved and relevant publications. There were no restrictions with respect to language, date of publication or study setting.

Selection criteria: 

Randomised controlled trials (RCTs) and quasi-randomised controlled trials comparing the use of disposable surgical masks with the use of no mask.

Data collection and analysis: 

Two review authors extracted data independently.

Main results: 

We included three trials, involving a total of 2106 participants. There was no statistically significant difference in infection rates between the masked and unmasked group in any of the trials. We identified no new trials for this latest update.

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