Effectiveness of four topical treatment methods in a rat model of superficial partial-thickness burn injury: the advantages of combining zinc-hyaluronan gel with silver foam dressing.

BACKGROUND: There are several options available for conservative treatment of partial-thickness burns, however, reliable, affordable, and easily obtainable animal testing models are hard to find for the comparison of the different treatment methods. We aimed at developing a preclinical testing model and at comparing four treatment methods for superficial partial-thickness burns. METHODS: Burn injury was induced in 90 adult male Wistar rats by placing the 130°C hot tip of a commercially obtainable soldering device for 30 s on the clipped skin of the interscapular region at a steady pressure. Skin histology was studied on days 5, 10, and 22 after the induction of the burn injury, on which days, respectively, the ratio of the not epithelialized wound (%), the extent of re-epithelialization (score), and the scar thickness (µm) were assessed. We compared 4 groups: silver-sulfadiazine cream, zinc-hyaluronan gel, silver foam dressing, and the combination of zinc-hyaluronan gel with a silver foam dressing. RESULTS: On day 5, the induction of superficial partial-thickness burn injury was confirmed histologically in the rats. The zinc-hyaluronan gel and the combination treatment resulted in a markedly smaller ratio of the non-epithelialized area (29 ± 10% and 28 ± 13%, respectively) than silver-sulfadiazine cream (69 ± 4%; p < 0.01). On day 10, the extent of re-epithelialization was the lowest (∼0.2) in the silver-sulfadiazine cream group, while the other 3 treatments performed significantly better. The combination treatment lead to the maximal score of 2 in all rats, which was higher than in the other 3 treatment groups. On day 22, the scar thickness was the smallest in the combination treatment group (560 ± 42 µm), which was significantly less than in the silver-sulfadiazine cream group (712 ± 38 µm; p < 0.05). CONCLUSIONS: We designed and histologically confirmed a reproducible method for induction of superficial partial-thickness burns in rats for preclinical testing. In our model, the combination of zinc-hyaluronan gel with silver foam dressing was more effective than either of its components alone or than silver-sulfadiazine cream.

Noninvasive ventilation improves the outcome in patients with pneumonia-associated respiratory failure: Systematic review and meta-analysis.

BACKGROUND: Noninvasive ventilation (NIV) is beneficial in exacerbations of chronic obstructive pulmonary disease (COPD), but its effectiveness in pneumonia-associated respiratory failure is still controversial. In the current meta-analysis, we aimed to investigate whether the use of NIV before intubation in pneumonia improves the mortality and intubation rates of respiratory failure as compared to no use of NIV in adults. METHODS: We searched three databases from inception to December 2019. We included studies, in which pneumonia patients were randomized initially into either NIV-treated or non-NIV-treated groups. Five full-text publications, including 121 patients, reported eligible data for statistical analysis. RESULTS: With NIV the overall hospital mortality rate seemed lower in patients with pneumonia-associated respiratory failure, but this was not significant [odds ratio (OR) = 0.39; 95% confidence interval (CI): 0.13-1.14; P = 0.085]. In the intensive care unit, the mortality was significantly lower when NIV was applied compared to no NIV treatment (OR = 0.22; 95% CI: 0.07-0.75; P = 0.015). NIV also decreased mortality compared to no NIV in patient groups, which did not exclude patients with COPD (OR = 0.25; 95% CI: 0.08-0.74; P = 0.013). The need for intubation was significantly reduced in NIV-treated patients (OR = 0.22; 95% CI: 0.09-0.53; P = 0.001), which effect was more prominent in pneumonia patient groups not excluding patients with pre-existing COPD (OR = 0.13; 95% CI: 0.03-0.46; P = 0.002). CONCLUSION: NIV markedly decreases the death rate in the intensive care unit and reduces the need for intubation in patients with pneumonia-associated respiratory failure. The beneficial effects of NIV seem more pronounced in populations that include patients with COPD. Our findings suggest that NIV should be considered in the therapeutic guidelines of pneumonia, given that future clinical trials confirm the results of our meta-analysis. AVAILABILITY OF DATA AND MATERIALS: All data and materials generated during the current study are available from the corresponding author on reasonable request.

Hyperthermia induced by transient receptor potential vanilloid-1 (TRPV1) antagonists in human clinical trials: Insights from mathematical modeling and meta-analysis.

Antagonists of the transient receptor potential vanilloid-1 (TRPV1) channel alter body temperature (Tb) in laboratory animals and humans: most cause hyperthermia; some produce hypothermia; and yet others have no effect. TRPV1 can be activated by capsaicin (CAP), protons (low pH), and heat. First-generation (polymodal) TRPV1 antagonists potently block all three TRPV1 activation modes. Second-generation (mode-selective) TRPV1 antagonists potently block channel activation by CAP, but exert different effects (e.g., potentiation, no effect, or low-potency inhibition) in the proton mode, heat mode, or both. Based on our earlier studies in rats, only one mode of TRPV1 activation - by protons - is involved in thermoregulatory responses to TRPV1 antagonists. In rats, compounds that potently block, potentiate, or have no effect on proton activation cause hyperthermia, hypothermia, or no effect on Tb, respectively. A Tb response occurs when a TRPV1 antagonist blocks (in case of hyperthermia) or potentiates (hypothermia) the tonic TRPV1 activation by protons somewhere in the trunk, perhaps in muscles, and - via the acido-antithermogenic and acido-antivasoconstrictor reflexes - modulates thermogenesis and skin vasoconstriction. In this work, we used a mathematical model to analyze Tb data from human clinical trials of TRPV1 antagonists. The analysis suggests that, in humans, the hyperthermic effect depends on the antagonist's potency to block TRPV1 activation not only by protons, but also by heat, while the CAP activation mode is uninvolved. Whereas in rats TRPV1 drives thermoeffectors by mediating pH signals from the trunk, but not Tb signals, our analysis suggests that TRPV1 mediates both pH and thermal signals driving thermoregulation in humans. Hence, in humans (but not in rats), TRPV1 is likely to serve as a thermosensor of the thermoregulation system. We also conducted a meta-analysis of Tb data from human trials and found that polymodal TRPV1 antagonists (ABT-102, AZD1386, and V116517) increase Tb, whereas the mode-selective blocker NEO6860 does not. Several strategies of harnessing the thermoregulatory effects of TRPV1 antagonists in humans are discussed.

Systemic antibiotic prophylaxis does not affect infectious complications in pediatric burn injury: A meta-analysis.

In pediatric burns the use of systemic antibiotic prophylaxis is a standard procedure in some burn centers, though its beneficial effect on the infectious complications is debated. The present meta-analysis aimed at determining whether systemic antibiotic prophylaxis prevents infectious complications in pediatric patients with burn injuries. We searched the PubMed, EMBASE, and Cochrane Library databases from inception to August 2019. We included 6 studies, in which event rates of infectious complications were reported in children with burn injuries receiving or not receiving systemic antibiotic prophylaxis. We found that the overall odds ratio (OR) of developing an infection (including local and systemic) was not different between the groups (OR = 1.35; 95% CI, 0.44, 4.18). The chances for systemic infectious complications alone were also not different between antibiotic-treated and non-treated patients (OR = 0.74; 95% CI, 0.38, 1.45). Based on the age, affected total body surface area, and country income level, we did not find any subgroup that benefited from the prophylaxis. Our findings provide quantitative evidence for the inefficacy of systemic antibiotic prophylaxis in preventing infections in pediatric burns. To validate our conclusion, multinational, randomized trials in a diverse population of children with burn injuries are warranted.

Treatment of partial thickness hand burn injuries in children with combination of silver foam dressing and zinc-hyaluronic gel: Case reports.

RATIONALE: Burns is a common type of traumatic injury in childhood. Nowadays, several wound dressings are available to treat the second-degree hand burns conservatively. PATIENT CONCERNS, DIAGNOSES: At the authors' institute, 37 children were treated conservatively with a special dressing at first intervention containing Aquacel Ag foam and Zn-hyaluronic gel to determine their effectiveness on partial thickness hand burns. INTERVENTIONS: The dressing was checked on the second day, and removed on the sixth or seventh day (unless it had spontaneously separated). OUTCOMES: None of the 37 children treated with this dressing were diagnosed with wound infection. The authors observed the epithelialization of the burned areas on the 6-7th day after primary conservative treatment. The dressing efficiently promotes epithelialization in all cases. Further advantage of Zn-hyaluronic gel is to enhance cell regeneration and inhibits dressing fixation into the wound. LESSONS: Based on the authors' experience, with this special combination of wound dressing, a gentle, child-friendly, cost-effective treatment and excellent wound healing observed with favourable cosmetic results.