Abstract: Eleven studies with a total of 886 participants were included in the review. These evaluated a range of comparisons in a range of surgical wounds healing by secondary intention. In general studies were small and some did not present data or analyses that could be easily interpreted or related to clinical outcomes. These factors reduced the quality of the evidence. Two comparisons compared different iodine preparations with no antiseptic treatment and found no clear evidence of effects for these treatments. The outcome data available were limited and what evidence there was low quality. One study compared a zinc oxide mesh dressing with a plain mesh dressing. There was no clear evidence of a difference in time to wound healing between groups. There was some evidence of a difference in measures used to assess wound infection (wound with foul smell and number of participants prescribed antibiotics) which favoured the zinc oxide group. This was low quality evidence. One study reported that sucralfate cream increased the likelihood of healing open wounds following haemorrhoidectomy compared to a petrolatum cream (RR: 1.50, 95% CI 1.13 to 1.99) over a three week period. This evidence was graded as being of moderate quality. The study also reported lower wound pain scores in the sucralfate group. There was a reduction in time to healing of open wounds following haemorrhoidectomy when treated with Triclosan post-operatively compared with a standard sodium hypochlorite solution (mean difference -1.70 days, 95% CI -3.41 to 0.01). This was classed as low quality evidence. There was moderate quality evidence that more open wounds resulting from excision of pyomyositis abscesses healed when treated with a honey-soaked gauze compared with a EUSOL-soaked gauze over three weeks' follow-up (RR: 1.58, 95% CI 1.03 to 2.42). There was also some evidence of a reduction in the mean length of hospital stay in the honey group. Evidence was taken from one small study that only had 43 participants. There was moderate quality evidence that more Dermacym®-treated post-operative foot wounds in people with diabetes healed compared to those treated with iodine (RR 0.61, 95% CI 0.40 to 0.93). Again estimates came from one small study with 40 participants. There is no robust evidence on the relative effectiveness of any antiseptic/antibiotic/anti-bacterial preparation evaluated to date for use on SWHSI. Where some evidence for possible treatment effects was reported, it stemmed from single studies with small participant numbers and was classed as moderate or low quality evidence. This means it is likely or very likely that further research will have an important impact on our confidence in the estimate of effect, and may change this estimate.

Plain-language summary: In November 2015 we searched for as many studies as possible that both had a randomised controlled design and looked at the use of an antibiotic or antiseptic in participants with surgical wounds healing by secondary intention. We found 11 studies which included a total of 886 participants.These all looked at different comparisons. Several different types of wounds were included. Studies looked at wounds after diabetic foot amputation, pilonidal sinus surgery, treatment of various types of abscess, surgery for haemorrhoids, complications after caesarean section and healing of openings created by operations such as colostomy. Most studies compared a range of different types of antibacterial treatments to treatments without antibacterial activity, but four compared different antibacterial treatments. Although some of the trials suggested that one treatment may be better than another, this evidence was limited by the size of the studies and the ways they were carried out and reported. All of the studies had low numbers of participants and in some cases these numbers were very small. Many of the studies did not report important information about how they were carried out, so it was difficult to tell whether the results presented were likely to be true. More, better quality, research is needed to find out the effects of antimicrobial treatments on surgical wounds which are healing by secondary intention. Assessed as up to date November 2015.