Skin irritation and sensitization of swine acellular dermal matrix treated with hyaluronic acid / 中华烧伤杂志

<p><b>OBJECTIVE</b>To evaluate the skin irritation and sensitization potential of the swine acellular dermal matrix treated with hyaluronic acid (SADM-HA).</p><p><b>METHODS</b>(1) Skin irritation test. Twelve New Zealand rabbits were divided into SADM-HA group, allogeneic skin group, and (human) xeno-skin group according to the random number table, with 4 rabbits in each group. Four test sites were designed on the back of each rabbit. Two test sites of each rabbit in the three groups were covered with SADM-HA, allogeneic skin, and xeno-skin, respectively. Another test site was covered with gauze containing 200 g/L sodium dodecyl sulfate solution as positive control. The last test site was covered with gauze containing normal saline as negative control. The primary irritation index and cumulative irritation index of each material were calculated. (2) Skin closed-patch test. Sixty guinea pigs were used. Fifty-four guinea pigs were divided into SADM-HA group, allogeneic skin group, and (human) xeno-skin group according to the random number table, with 18 guinea pigs in each group. Twelve guinea pigs in each of the three groups were correspondingly induced and stimulated by SADM-HA, allogeneic skin, and xeno-skin, with 6 guinea pigs in each group treated with ethanol-soaked gauze to serve as negative control. The remaining 6 guinea pigs were treated with gauze containing 25% α-hexylcinnamaldehyde ethanol solution as positive control. The rating scales of Magnusson and Kligman were used to grade the condition of skin after being treated with above-mentioned materials to evaluate skin sensitivity to them at post stimulation hour 24 and 48. Data were processed with the non-parametric test of independent samples.</p><p><b>RESULTS</b>(1) In the skin irritation test, the primary irritation indexes of the three dressings in SADM-HA group, allogeneic skin group, and xeno-skin group were respectively -0.04, 0.13, and 0.08. The cumulative irritation indexes of the three dressings in SADM-HA group, allogeneic skin group, and xeno-skin group were respectively 0.27, 0.10, and 0.25, which were close to those of negative control within the three groups. The skin irritation of each of the three materials was negligible. (2) In the skin closed-patch test, all scores of the three dressings in SADM-HA group, allogeneic skin group, and xeno-skin group were between 0 and 1. The scores of SADM-HA group and allogeneic skin group were close to those of negative control within the two groups (with U values respectively 188.00 and 90.00, P values both above 0.05). The differences were statistically significant between each material of the three groups and positive control (with U values respectively 19.00, 59.00, 21.50, P values all below 0.01).</p><p><b>CONCLUSIONS</b>The SADM-HA is safe and reliable without skin irritation and sensitization, and it has encouraging prospect in clinical application.</p>

Large-area burns with pandrug-resistant Pseudomonas aeruginosa infection and respiratory failure / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Infection due to pandrug-resistant Pseudomonas aeruginosa (PDRPA) has become a challenge in clinical practice. The aim of this research was to summarize the treatment of large-area burns (60% - 80%) with PDRPA infection and respiratory failure in our hospital over the last two years, and to explore a feasible treatment protocol for such patients.</p><p><b>METHODS</b>We retrospectively analyzed the treatment of five patients with large-area burns accompanied by PDRPA infection and respiratory failure transferred to our hospital from burn units in hospitals in other Chinese cities from January 2008 to February 2010. Before PDRPA infection occurred, all five patients had open wounds with large areas of granulation because of the failure of surgery and dissolving of scar tissue; they had also undergone long-term administration of carbapenems. This therapy included ventilatory support, rigorous repair of wounds, and combined antibiotic therapy targeted at drug-resistance mechanisms, including carbapenems, ciprofloxacin, macrolide antibiotics and β-lactamase inhibitors.</p><p><b>RESULTS</b>Four patients recovered from burns and one died after therapy.</p><p><b>CONCLUSIONS</b>First, compromised immunity caused by delayed healing of burn wounds in patients with large-area burns and long-term administration of carbapenems may be the important factors in the initiation and progression of PDRPA infection. Second, if targeted at drug-resistance mechanisms, combined antibiotic therapy using carbapenems, ciprofloxacin, macrolide antibiotics and β-lactamase inhibitors could effectively control PDRPA infection. Third, although patients with large-area burns suffered respiratory failure and had high risks from anesthesia and surgery, only aggressive skin grafting with ventilatory support could control the infection and save lives. Patients may not be able to tolerate a long surgical procedure, so the duration of surgery should be minimized, and the frequency of surgery increased.</p>