Use of Nile Tilapia Fish Skin as a Xenograft for Burn Treatment: Phase III Study

Number of days until complete reepithelialization of the burn wound, considering application of the first dressing as day zero. Complete reepithelialization was defined as a ≥95% reepithelialization calculated via clinical judgment from the consultant

In the control group, a dressing change was defined as the act of cleaning the wound and reapplying the Silver Sulfadiazine Cream 1%, which was performed every 48 hours. In the test group, a dressing change was defined as the act of replacing the Nile Tilapia Fish Skin which did not adhere properly and/or replacing gauze and bandage that is full of exudate.

In order to audit analgesic intake, apart from the medication prescription (dipyrone and/or tramadol), the patients received a daily record card. They were asked to take the medication only if they felt pain, always respecting instructions in the prescription, and to register the amount of medication taken and the date on the card. Upon returning for medical evaluation, the remaining medication was checked and compared to the daily record card.

Consumption of materials of the burn treatment center was controlled by the completion of a specific form, an activity performed at the end of each patient visit by the nursing staff. The resources consumed were divided into three categories: a) products used for wound management (either Nile Tilapia Fish Skin or Silver Sulfadiazine Cream 1%); (b) hospital material required for dressing preparation (such as sterile gloves, chlorhexidine, gauze, and bandage); and c) analgesic medication required throughout treatment (dipyrone and/or tramadol). Human resources were not evaluated.

Patients were informed that the left end of the 10 cm horizontal line (with a "0") represented "no pain" and that the right end (with a "10") represented the "most severe pain imaginable." They were asked to make a mark on the line that represented their current pain intensity, and the Visual Analogue Scale pain intensity level was scored by measurement of the distance from the mark to the "no pain" end of the line.

In the Electronic von Frey, a rigid tip of 0.7 mm in diameter is connected to an electronic system, which displays the test readings in grams (from 0.1 to 1000 g). Initially, 4 different points around the burn were chosen, each one with a distance of around 1 cm from the wound bed. The tip was applied perpendicularly to the skin surface in each of these points, with the application rate controlled entirely by the observer. The participants gave a verbal signal when the pressure was felt to be unpleasant: this measure was taken as the Mechanical Pain Threshold of that point. Subsequently, the process was repeated in a similar region of the contralateral healthy side of the body. The mean of the measures of the 4 points in each area was taken as the mean Mechanical Pain Threshold of that area. Finally, the difference between the nociception threshold of healthy skin and of the edge of the burn, expressed in grams, was determined.

The Brazilian version of the 9-item Burns Specific Pain Anxiety Scale (BSPAS) was employed. Each item in the BSPAS is scored on a 10 cm visual analogue line with two reference points given values of 0 and 10. The patient is asked how much the assertions relate to their current pain situation, with 0 corresponding to ''not at all'' and 10 corresponding to ''the worst imaginable way''. The total score is calculated by adding up the scores for all items, with a maximum of 90 points.

Assessed via the Clinical Global Impression Scale-Improvement (CGI-I). The CGI-I is evaluated by the physician responsible and answers the following question: "Compared to the patient's condition at admission to the project, this patient's condition is: 1 - very much improved since the initiation of treatment; 2 - much improved; 3 - minimally improved; 4 - no change from baseline; 5 - minimally worse; 6 - much worse; 7 - very much worse since the initiation of treatment".