Advances in Burn Management

An estimated 486,000 burns are treated annually by medical professionals in the United States, about 40,000 in hospitals.¹ Epidermal and deeper partial-thickness burns involving dermal blood vessels, hair follicles, and nerves are typically managed without surgical intervention. Full-thickness burns extending into subdermal structures respond best to early excision and grafting, which is now considered the standard of care. As with chronic venous or pressure ulcers,² full-thickness burns take longer to heal than partial-thickness ones. In this month’s Evidence Corner, we review recent randomized clinical trials exploring burn management interventions. The first study explores an intervention that may improve the standard of care for full-thickness burns.³ The second casts light on the controversy surrounding safety and efficacy of topical silver interventions on deep partial-thickness burns.⁴

Laura Bolton, PhD
Adjunct Associate Professor
Department of Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ

Reference: Gardien KL, Marck RE, Bloemen MC, et al. Outcome of burns treated with autologous cultured proliferating epidermal cells: a prospective randomized multicenter intra-patient comparative trial. Cell Transplant. [Epub ahead of print September 28, 2015].

Rationale: Split-thickness skin grafts (SSG) are standard treatment for full-thickness burns, but their use often results in scar formation. Would scar formation be limited by adding topical cultured autologous epidermal keratinocytes and melanocytes (epidermal cells [EC]) to standard SSG?

Objective: Conduct a randomized controlled trial (RCT) to explore healing and scar quality effects of adding topical EC to standard SSG for treatment of full-thickness clinical burns.

Methods: A prospective multicenter intrapatient comparison RCT assigned 2 comparable acute full-thickness burn areas on each of 40 adult patients to standardized SSG treatment with or without EC seeded onto a collagen carrier. The primary outcome was percent wound reduction in the area 5-7 days after grafting. Secondary outcomes were safety, graft take at 5-7 days, and scar quality as measured after 3 months (n = 33) or 12 months (n = 28) by the Patient and Observer Scar Assessment Scale (POSAS) score, skin color,  and elasticity. Primary differences were tested using a nonblinded-evaluated Wilcoxon comparison.

Results: There was consistently more epithelization in the EC-treated portion of each burn healed at 5-7 days for the site receiving EC (71%) compared to 67% for the non-EC site (P = 0.03). The POSAS scores for redness, pigmentation, thickness, relief, and pliability improved in the EC-treated sites along with elasticity at 3 months; melanin index at 3 months and 12 months, and erythema index at 12 months (P < 0.05).

Authors’ Conclusions: Though limited by its nonblinded evaluation, this study reported that adding EC to standard SSG treatment improved burn wound healing and scar quality.

Reference: Tang H, Lv G, Fu J, et al. An open, parallel, randomized, comparative, multicenter investigation evaluating the efficacy and tolerability of Mepilex Ag versus silver sulfadiazine in the treatment of deep partial-thickness burn injuries. J Trauma Acute Care Surg. 2015;78(5):1000-1007.

Rationale: Silver sulfadiazine (SSD) gauze is commonly used as a topical dressing for deep partial–thickness burns. Newer dressing materials for partial-thickness burns should be compared to this standard of care.

Objective: Compare the efficacy and tolerability of SSD gauze to that of an absorbent foam silver (AFS) dressing on patients with deep partial-thickness burn injuries covering 2.5% -25% of body surface area.

Methods: Patients between 5 years and 65 years of age, with deep partial-thickness burn injuries covering 2.5%-25% of body surface area in 9 Chinese hospital departments of burn surgery were randomly assigned to have their burns dressed with either SSD with gauze applied daily (n = 82) or AFS applied every 5-7 days (n = 71) for up to 4 weeks. The primary outcome, evaluated by observers who were aware of the treatment received, was median time to healing. Patient-reported dressing tolerability and percent of burn area healed by the study’s end were secondary outcomes.

Results: The 2 groups experienced similar healing time, with 79% of each group healing in a median of 15 days with the AFS dressing or 16 days with the SSD dressing (P = 0.74). All secondary outcomes were also comparable. The only significant difference was that more dressings were used in the daily changed SSD group: 14 compared to 3 in the AFS group (P < 0.0001).

Authors’ Conclusions: There was no difference in healing rates or dressing tolerability for the 2 groups. The longer dressing wear for the AFS promoted longer undisturbed healing and made it easier for patients to continue with their normal lives sooner.

Topical cultured autologous epidermal keratinocytes and melanocytes subtly improved epithelization and subsequent scar elasticity and erythema for 3-12 months.³ This research highlights the potential for some aspect of this topical treatment to advance the standard of care for full-thickness burn grafting. The authors correctly note that blinding at least the outcome evaluation of this RCT would result in more compelling results. These results suggest the merit of further double-blind research exploring effects of vehicle, cell types, and cover dressings to define optimal parameters for cell harvesting, preparation, and application when treating graft sites with EC.

The partial-thickness burn findings of 15-day healing times⁴ are consistent with healing times reported previously^5,6 for similar burns dressed with gauze dressings impregnated with SSD. This research⁴ allays fears that SSD-based dressings may delay healing; however, use of moisture-retentive hydrocolloid dressings has permitted significantly faster healing and reduced pain^5-7 of partial-thickness burns compared to SSD gauze in prior studies.

Ideally, future clinical trials will use as standard of care moisture-retentive dressings to limit patient-reported pain and healing time of deep or shallow partial-thickness burns. Both these studies^3,4 underscore the need to improve management for full-thickness or partial-thickness burns.