Simple Wound Irrigation in the Postoperative Treatment for Surgically Drained Spontaneous Soft Tissue Abscesses: Study Protocol for a Prospective, Single-Blinded, Randomized Controlled Trial.

BACKGROUND: Skin abscesses are a frequent encountered health care problem and lead to a significant source of morbidity. They consequently have an essential impact on the quality of life and work. To date, the type of aftercare for surgically drained abscesses remains under debate. This leads to undesirable practice variations. Many clinical standard protocols include sterile wound dressings twice a day by a home-care service to reduce the chance of a recurrent wound infection. It is unknown, however, whether reinfection rates are comparable to adequate wound irrigation with a nonsterile solution performed by the patient. Our hypothesis is that simple wound irrigation with nonsterile water for postoperative wound care after an abscess is surgically drained is feasible. We assume that in terms of reinfection and reintervention rates unsterile wound irrigation is equal to sterile wound irrigation.

OBJECTIVE: The primary aim of this study is therefore to investigate if there is a need for sterile wound irrigation after surgically drained spontaneous skin abscesses.

METHODS: In a prospective, randomized controlled, single-blinded, single-center trial based on a noninferiority design, we will enroll 128 patients randomized to either the control or the intervention group. The control group will be treated according to our current, standard protocol in which all patients receive a sterile wound irrigation performed by a home-care service twice a day. Patients randomized to the intervention group will be treated with a nonsterile wound irrigation (shower) twice a day. All patients will have a routine clinical control visit after 1, 3, 6, and 12 weeks in the outpatient clinic. Primary outcome is the reinfection and reoperation rate due to insufficient wound healing diagnosed either at the outpatient control visit or during general practitioner visits. Secondary outcome measures include a Short Form Health Survey, Visual Analog Scale, Patient and Observer Scar Assessment Scale, Vancouver Scar Scale, and the EurolQol 5-Dimension Questionnaire. Those questionnaires will be completed at the outpatient control visits.

RESULTS: The trial was started in June 2016 and enrolled 50 patients by article publication. Regarding the adherence to our protocol, we found 10% of loss to follow-up until now. Only 2 patients needed reoperation and only 1 patient needed a change of treatment (antiseptic therapy). Most patients are happy with their randomized treatment but as expected some patients in the sterile group complained about timing problems with their working hours and home-care service appointments. Most patients in the nonsterile group are satisfied being able to take care of their wounds independently although some patients still depend on the home-care service for the wound dressing. We are hoping to have enrolled enough patients by summer 2017. The follow-up will take until autumn 2017, and study results are expected to be published by the end of 2017. This trial is solely supported by the cantonal hospital of Lucerne.

CONCLUSIONS: Nonsterile wound irrigation is more likely to be carried out independently by the patient than sterile wound irrigation. Therefore, if nonsterile wound care shows comparable results in terms of reinfection and reintervention rates, patient independence in the aftercare of surgically drained abscesses will increase, patients can return to work earlier, and health care costs can be reduced. In a preliminary, conservative estimation of health care costs, an annual savings of 300,000 CHF will be achieved in our hospital.

TRIAL REGISTRATION: German Clinical Trials Register DRKS00010418; https://drks-neu.uniklinik-freiburg.de/ drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00010418 (Archived by WebCite at https://www.webcitation.org/6q0AXp5EX).