Title: Single Use Negative pRessure dressing for Reduction In Surgical site infection following Emergency laparotomy- the SUNRRISE Trial
Funder: Department of Health and Social Care

Abstract: Background Surgical site infection (SSI) is a post-operative complication that causes significant pain, suffering and even death. In the UK over 30,000 emergency laparotomy operations are performed every year, these have SSI rates of 25-40%. SSIs are associated with prolonged inpatient stay, additional outpatient treatment, increased morbidity and mortality and, at an average cost of &pound;3500 per infection, are a significant financial burden on the NHS. Negative pressure wound therapy has been used since the mid-1990s to manage and promote healing in chronic open wounds. The closed negative-pressure environment serves to prevent bacterial ingress and removes blood and serous fluid exuding from the wound. Recently, single-use negative pressure dressings (SUNPD) have been developed for use on primarily closed incisions. These devices are small, highly portable and simple to apply. Their use in studies of non-abdominal wall incisions has resulted in a 50-80% reduction in SSI. However, no randomised controlled trials exploring the clinical effectiveness of SUNPD in reducing SSIs in patients undergoing abdominal surgery have been reported. Aims The SUNRRISE trial is a pragmatic, multicentre, phase III randomised controlled trial comparing the use of SUNPD against the current standard practice (simple passive self-adhesive wound dressings) to reduce the rate of SSI after emergency laparotomy surgery. The primary outcome will be rate of SSI within 30 days and secondary outcomes will be length of stay, readmission rate, re-intervention rate, adverse events, patient and clinician acceptability, quality of life and cost effectiveness. Methodology SUNRRISE is a two stage trial; an internal feasibility study followed by the phase III trial. The project will be undertaken over a 30-month period at centres across the UK. Any site undertaking emergency abdominal surgery will be eligible to participate in the trial. All adults undergoing emergency laparotomy will be eligible for inclusion. We will exclude patients aged less than 16 years, operations performed laparoscopically, planned incision of less than 5cm, planned laparostomy, and patients with abdominal surgery within the preceding three months. Patients that are unable to provide consent due to long-term conditions will be excluded. Patients will be randomised in theatre following closure of skin to receive either SUNPD or standard practice in a 1:1 ratio. The randomisation will be stratified according to hospital site, stoma formation and intra-peitoneal contamination level. The primary outcome measure will be assessed by a member of the research team that is blinded to arm allocation. The trial will recruit a total of 630 patients. Sample size calculations are estimated on a baseline SSI rate of 25%. This conservative rate is supported by the findings of the ROSSINI trial and other high quality prospectively collected data sources exploring this high risk population. With an estimated relative reduction in SSI rates of 40% (to an actual SSI rate of 15%) the number needed in each arm at 80% power and a significance level of 5% is 250 patients. Allowing for a 20% attrition rate, 630 patients are required. The estimated effect size of 40% is a pooled conservative estimate from all of the published trials of this intervention (which quote 50-80% reduction). All data will be analysed on an Intention To Treat basis. Estimates of treatment effects will be presented with 95% confidence intervals. P-values will be from two-tailed tests. A p-value of Potential benefits This trial will explore clinical effectiveness of a novel intervention to reduce SSI rates in this unwell cohort of patients. If successful, it has the potential to result in significant improvements both for patients and the health service.

Lay abstract: Aim This study aims to test whether the use of a new type of active wound dressing can reduce rates of wound infection (also called surgical site infection or SSI ) after emergency surgery on the abdomen (tummy). Background Emergency abdominal operations are performed for a variety of life-threatening indications, including bowel blockages or perforations, traumatic injuries and major infections. Patients are left with large wounds on the abdomen, at least 1 in 4 of which will become infected. These SSIs are painful and take longer to heal, often resulting in a longer hospital stay and greater need for further wound care in the community. In an already unwell patient, development of an SSI can contribute to other major medical complications or even death. A special type of closed wound dressing, called a negative pressure dressing has recently been developed. This provides gentle suction to the wound and may help prevent development of an SSI. Negative pressure dressings are already used for some types of wounds and have been proven to be safe. However, they are more expensive so we need to be sure that that they are effective in reducing SSI before widespread uptake can be recommended within the NHS. Methods We are proposing a study to compare these new dressings against standard dressings in patients undergoing emergency abdominal operations to establish whether they are effective in reducing SSI rates. We will compare the number of SSIs and the overall costs of treatment between the two groups. Patient and Public Involvement/Dissemination Patients who have undergone emergency abdominal operations (with and without development of SSI) are involved in both the development and ongoing management of this study to ensure patients views and feelings are represented. Our findings will be published in international medical journals so that they can help patients globally.

Research activity codes: 6.4 SURGERY;6.3 MEDICAL DEVICES
Health categories: INFECTION