Effect Of Antibacterial Protease Combined With Silver Dressing On Chronic Wound With Bacterial Biofilm

[Obj ection]To compare the effects of two different interventions on chronic wounds with bacterial biofilm infection.To establish effective protocols and standardized procedures for clinical intervention on biofilm.To provide scientific guidance and evidence-based basis for clinical wound care staff to conduct biofilm management.[Methods]?Patients:During the period from March 2017 to December 2018,patients who met the inclusion and exclusion requirements were collected from the wound care center of the outpatient department of Eastern theater General Hospital.After signing the informed consent,a total of 60 patients were confirmed to be included,including 6 types of wounds:diabetic foot,arteries ulcer,venous ulcer,arteriovenous ulcer,traumatic ulcer and postoperative ulcer.?Clinical assessment and intervention:The first step is to clean the wound,the second step is to assess and measure the wound and record,the third step is to debride.Then in the experimental group after debridement,use the antibacterial protease for wet compressing.In the control group after debridement,use 0.9%NaCl for wet compressing.In the fifth step,the silver dressing was selected in both groups.In the last step,the wounds were wrapped by using sterile gauzes.The intervention duration was 28 days.?Indicator:Clinical indicators include wound volume reduction rate,pressure ulcer healing score(PUSH),wound temperature and pH.Laboratory indicators included wound bacterial infection rate,extracellular matrix(EPS)of wound bacterial biofilm and intramembrane bacterial reduction.[Results]? The patients' general information and the basic characteristics of the wound did not exist statistically difference(P>0.05).? There are statistic differences in wound reduction rate between two groups after intervention for14 days and 28 days(P=0.025,0.004).? Through repeated measurement variance analysis of PUSH score,wound temperature and pH,there are statistically significant in the wound PUSH(P=0.005)and pH(P=0.014)except wound temperature(P=0.995).?Wound bacterial infection:There were 15 cases of bacterial infection in the control group and 14 cases in the experimental group before treatment,with no statistical difference.After treatment,there were 11 and 4 cases respectively,with statistical difference(P=0.037).? The general morphology of the biofilm was observed by SEM,and the extracellular matrix(EPS)and intramembrane bacteria were reduced significantly after 28 days of treatment through CLSM combination with analysis of Image J software(P=0.041,0.011).[Conclusion]According to the clinical criteria and SEM or CLSM,the existence of bacterial biofilm in chronic wounds were identified.It has been preliminarily proved that the use of antibacterial protease combined with silver dressing can effectively reduce the volume of chronic wounds with bacterial biofilm infection,reduce the wound PH,reduce the bacterial infection rate,reduce the number of extracellular matrix and bacteria in the biofilm and promote wound healing.