Dressings for split thickness skin graft donor sites.

Background: The management of donor sites after harvesting of split thickness skin grafts is a challenge. Aim: The aim of this study was to compare three different dressings for split thickness skin donor sites. Methods: This study was designed as a prospective comparative study of 60 patients allocated to one of three donor site dressings groups, following harvesting of split skin. The first and second groups (n=20 for each) were treated with calcium sodium alginate dressings covered with transparent semi-occlusive films*, **, and the third group (n=20) with a hydrofibre dressing covered with a soft silicone foam dressing***. Endpoints were healing, pain, costs, and number of dressing changes. Results: No difference was found among the three groups with respect to healing and pain. Significantly more unplanned dressing changes were required in the second group (28) compared with the first and third groups (4 for each). Significantly lower total direct dressing costs were found in the first and third groups compared with the second group. The median ratios of total dressing costs were 1.13, 2.15, and 1.00 for the first through third groups, respectively. Conclusions: This study shows that two dressings, almost identically described by manufacturers, performed significantly differently when used clinically. The dressing with the lower per-dressing cost was the most expensive choice because of its high frequency of dressing changes. EWMA Journal 2014 vol 14 no 2 15 polyurethane film**. A hydrofibre dressing covered with soft silicone foam dressing was chosen as a third option for evaluation in this trial***. Therefore, the aim of this study was to compare these three different dressings used on donor sites after STSG harvesting. METHODS The study protocol was approved by the Central Region Denmark and by the Danish Data Protection Agency, and the study was conducted in accordance with good clinical practice and ethical principles consistent with the Declaration of Helsinki. This was a prospective comparative study with historic allocation to three groups, based on different products used as dressings for donor sites after harvesting STSGs. Group allocation to the three groups is shown in Figure 1. The first 20 patients were included in Group 1; they were treated with calcium sodium alginate dressings covered with transparent semi-occlusive film. The next 20 patients were included in Group 2; they were also treated with calcium sodium alginate dressings covered with transparent semi-occlusive film. The last 20 patients were included in Group 3; they were treated with a hydrofibre dressing covered with a soft silicone foam dressing. All adult (>18 years old) patients hospitalised or seen in the Department of Plastic Surgery’s outpatient clinic at the Aarhus University Hospital, Aarhus C, Denmark, between September 2010 and October 2011 were offered inclusion in the study if they required surgery to obtain an STSG from the anterior thigh. Only patients expected to have a donor site with an area <300 cm2 were included, to obtain donor sites suitable for comparison. All patients were informed about the study both orally and in writing by the coordinating investigator during a clinical consultation. Patients were excluded if they were not physically or mentally able to cooperate, had a history of allergy to dressings, or refused to provide consent. In the operating theatre, the STSG was harvested from the anterior aspect of the thigh of the patient using a dermatome or knife, according to standards for best practice. Immediately after split skin harvesting, the donor site was covered with adrenaline-soaked gauze (at a concentration of 1 mg adrenaline in 500 mL saline). After 10 minutes, the donor site was covered with a dressing according to the protocol and group allocation. The patients and staff could not be blinded to the chosen dressing because of the nature of the intervention and allocation in this study. According to the protocol, the donor site dressing was left unchanged until the first clinic visit, which was planned at 8 to 10 days postoperatively unless leakage occurred (see an example of a dressing without leakage in Figure 2A). The nurses were instructed to act in accordance with the standards of the department and good clinical practice in all instances, and to report all occurrences and actions taken. The entire dressing was removed and replaced with a new dressing identical to the initial dressing (according to the treatment group), if the maximum capacity of the dressing was exceeded, leading to leakage or a high risk of leakage (see an example of a dressing with leakage in Figure 2B). The dressing was left in place and simply reinforced along the edges if there was loosening of the top layer. If infection was suspected, the dressing was changed, and if signs of infection were confirmed, the site was treated with a silver dressing, according to our standard treatment for infected STSG donor sites. At the first planned clinic visit, the percentage of healing at the donor site, as well as patient-reported pain and discomfort, were recorded. All contacts with the patient and abnormalities at the donor Consort diagram Figure 1: Patients included and evaluated in the three groups. Figure 2A: Group 3 dressing on the ninth day, immediately prior to its removal. EWMA Journal 2014 vol 14 no 2 16 Science, Practice and Education  site areas were also recorded. Each donor site was photographed at the first clinic visit and weekly thereafter until complete healing occurred (see an example of complete healing in Figure 2C). Any unhealed area was redressed every third day during from first change of dressing until complete healing. The primary outcome measure was the percentage of healing at the first planned clinic visit, when the initial dressing was changed. Healing was recorded in 5-percentage increments, from 0 to 100% (e.g., 0%, 5%, 10%, etc.). As secondary outcome measures, the time to complete healing, number of dressing changes, and reported discomfort and pain intensity were recorded. The percentage of healing was assessed until 95% healing was obtained. The time to complete healing was recorded as the time (in days) from STSG harvesting until 95-100% healing was achieved. On the first day after surgery, the patients were asked to report their discomfort score, and they were asked to indicate their pain score three times: on the first day after STSG harvesting, and at the first planned clinic visit before and after the dressing was removed or changed. All scores were made using a numerical rating scale (NRS). Other observations, such as signs of infection, excessive wound exudate, leakage, and changing or reinforcement of dressings were also registered until the tenth postoperative day. Statistical assessments were performed using the MannWhitney rank sum test. A p-value of 0.05 was considered as the level of significance. RESULTS Sixty patients were enrolled in the study (Table 1). Three patients (one in group 1 and two in group 2) were excluded, because they did not return to the hospital for the planned clinic visit (see Consort diagram in Figure 1). There were no statistical differences among the three groups with respect to patient characteristics or size of the donor site (see Table 1). The median percentage of healing at the first planned clinic visit was 90%, 95%, and 98% in group 1, 2 and 3, respectively. For this primary outcome, there were no statistically significant differences among groups. The median (range) time to complete healing of the donor site was 13 (8-37), 14 (10-67), and 12 (8-35) days in group 1, 2 and 3, respectively (Fig. 3). These times were not significantly different among groups. Figure 2B: Donor site in group 2 in which the calcium sodium alginate dressing under the transparent semi-occlusive film has become displaced. Figure 2C: Healed split skin donor site in group 3 immediately after dressing removal. Table 1: Description of patients and donor sites for the three types of dressings Variable Group 1 Group 2 Group 3 Patients evaluated; patients included, (number) 19 (20) 18 (20) 20 (20) Patients with comorbidities and /or treatments (number) Diabetes 2 3 1 Immunosuppressant treatment 1 2 0 Anticoagulant therapy 8 5 5