Burn Debridement: Are We Optimizing Outcomes?

Early surgical debridement of nonviable tissue within 48 hours of burn injury is the standard of care (SOC) for burns extending into and beyond the deep dermis. Early debridement has been reported to reduce infection and complication rates, shorten hospital stays, and improve burn wound healing compared with delayed debridement of these burns.¹ However, surgical debridement challenges patients with considerable pain, blood and heat loss, and poor differentiation between viable and dead tissue resulting in unnecessary excision of healthy tissue.² Alternative debridement interventions, such as larval, enzymatic, hydrosurgical, or autolytic, have improved outcomes of chronic necrotic wounds^3,4 and may offer ways to spare healthy tissue and minimize the recognized challenges of surgical debridement in patients with deep dermal or full-thickness burns. This installment of Evidence Corner reviews recent research exploring hydrosurgical⁵ or bromelain-based enzyme⁶ interventions reported to improve burn debridement or repair beyond the current SOC.

Reference: Hyland EJ, D’Cruz R, Menon S, Chan Q, Harvey JG, Lawrence T, La Hei E, Holland AJ. Prospective, randomised controlled trial comparing Versajet™ hydrosurgery and conventional debridement of partial thickness paediatric burns [published online February 25, 2015]. Burns. 2015;41(4):700–707.

Rationale: Conventional standard of care (SOC) surgical debridement of burn wounds involves tangential excision or dermabrasion of the burn eschar to the plane of punctate bleeding, the indicator of viable dermis. Hydrosurgery has been used to accomplish the same goal, while sparing more dermal tissue, and may reduce scarring.

Objective: A prospective, randomized clinical trial (RCT) compared debridement efficacy and 3- and 6-month scarring of pediatric non-facial burn wounds debrided using surgical SOC or hydrosurgery.

Methods: Children 16 years of age or younger undergoing debridement and skin grafting for non-facial partial-thickness burns were randomly assigned to receive debridement using hydrosurgery (n = 30) or SOC (n = 31). Before and after debridement, 2-mm punch biopsies assessed debridement adequacy and dermal sparing. Other outcomes measured were duration of surgery, percentage of graft take 10 days postoperatively, healing time, postoperative infection, and scarring 3 and 6 months following surgery. Appropriate statistics for continuous or discrete variables were used to test for differences between groups, with statistical significance set at P < .05.

Results: More viable dermis was spared in those receiving hydrosurgery (P < .02). Graft take 10 days after debridement was similar for both groups (P = .90), with no significant difference in the duration of surgery, healing time, incidence of postoperative infection, or scarring 3 or 6 months after debridement.

Authors’ Conclusions: Although more viable dermal tissue was spared in those debrided using hydrosurgery, this did not affect graft take, infection incidence, or scarring 3 or 6 months after debridement.

Reference: Loo YL, Goh BKL, Jeffery S. An overview of the use of bromelain-based enzymatic debridement (Nexobrid^®) in deep partial and full thickness burns: appraising the evidence. J Burn Care Res. 2018;39(6):932–938.

Rationale: Increasing research has explored benefits and drawbacks of surgical SOC compared with enzymatic debridement using a debriding gel (BDG) containing the enzyme bromelain derived from pineapple stems. The BDG is CE-marked, indicated for deep partial- or full-thickness burns on up to 17% of total body surface area (TBSA), but parameters of use and efficacy compared with surgical SOC remain to be explored.

Objective: Review controlled and uncontrolled clinical studies appraising methods and outcomes of BDG use to debride deep dermal and full-thickness burns. 

Methods: Authors searched PubMed, Ovid, MEDLINE, Web of Science, and EMBASE electronic databases from 1986 to 2017 for clinical studies using BDG to debride deep partial- and full-thickness burns. Non-English studies, case reports, preclinical studies, and studies that did not use the CE-marked BDG were excluded. Patients in both groups received analgesia 10 to 15 minutes before debridement to reduce related pain. The SOC for deep partial- or full-thickness wounds consisted of tangential excision of necrotic tissue using a scalpel, hydrosurgery, or dermabrasion followed by autografting or, if appropriate, wound dressings. The BDG treatment consisted of a 1-mm to 3-mm thick layer of BDG (2 g of enzyme powder in 20 mL of a buffered aqueous polyacrylic acid gel) spread over each percent of TBSA to be debrided. A polyurethane occlusive sheet covered the BDG and sealed to the surrounding intact skin with a layer of sterile petrolatum ointment to protect intact skin from bromelain contact. After 4 hours, the film and BDG were removed, and the burn wound was scrubbed with gauze soaked in normal saline until a clean, bleeding wound bed was exposed. The wounds then were dressed for 2 hours with an antibacterial-soaked dressing to remove residual BDG and dissolve eschar before efficacy of eschar removal was assessed. For both groups, large, full-thickness defects exposed by debridement then were dressed with wet-to-dry dressings before being autografted as early as possible or covered with skin substitutes as needed until autografting was possible. Studies were tabulated and categorized as RCTs, non-controlled clinical trials, or anecdotal, either supporting or refuting reported clinical outcomes of reduced time to complete debridement or wound closure, need for surgery or for autograft, area of burns excised, and improved scar quality measured using validated scar scales. Individual study statistics were reported using intent-to-treat paired t tests or analyses of variance with significance set at P < .05 for the RCTs reported. Incidence or frequency data were compared using appropriate chi-squared or Fisher’s exact tests. Due to heterogeneity and lack of objective consistency in assessing baseline burn depths, a meta-analysis of early diagnosis-based treatment effects was not performed.

Results: Seven prospective studies on 327 patients treated with BDG reported its safety or efficacy parameters. Four RCTs on 127 patients (burns > 10%–16% TBSA) treated with BDG reported 1 or more outcomes tabulated compared with 134 comparable SOC control patients. Studies were small and generally of low quality with potential bias. Three of the RCTs had less likely bias as outcome assessors were blinded to treatment. Among the RCTs, 3 reported earlier debridement in 1 to 2 days after admission using BDG as compared with 8 to 11 days using SOC (all P values < .001). One RCT reported fewer surgical operations to complete debridement and burn healing with BDG as compared with SOC (P < .001). One RCT reported 24% of burn wounds were excised after BDG debridement, compared with 70% of SOC-treated burns, with a smaller average of burn wound area excised with BDG (P < .001), reflecting more efficient debridement using BDG. Reduced need for autografting (P < .01) was supported by 3 RCTs. Scarring results were the only outcomes with inconsistent results across studies. Pain of the BDG procedure was reportedly comparable to that experienced using SOC.

Authors’ conclusions: Limited evidence suggests BDG use may improve debridement and reduce needs for repeated surgeries and autografting. More and larger studies are needed to confirm these findings.

The 2 studies^5,6 summarized highlighted opportunities to reduce the extent of surgical excision and autografting of deep partial- and full-thickness burns while improving their healing outcomes. This confirms findings of a systematic review⁷ suggesting hydrosurgery or BDG may be an effective alternative to surgical debridement. However, readers should be aware that surgical debridement SOC varies across burn centers so it is not clear if BDG outcomes would exceed those using SOC in any given burn center. For example, some burn centers use full-thickness excision of necrotic tissue and autografting when clearly needed, while using more conservative surgical debridement for necrotic zones of questionable depth, followed immediately by autolytic debridement with a hydrocolloid⁸ or honey⁹ dressing to spare healthy dermal tissue, optimize pain and healing, and minimize microbial burdens or hypergranulation. Unlike BDG, collagenase, an enzymatic debriding agent, has reported slow-acting or limited debridement,¹⁰ so it is not correct to assume all enzymes have similar debriding efficacy. Comparative analyses of registries and RCTs reporting clinical outcomes while using different evidence-based interventions within SOC technique may increase the understanding of what works best for burn wounds. It may not be a question of using either BDG or hydrosurgery, surgical, larval, or autolytic debridement on patients with deep dermal or full-thickness burns. It may be more fruitful to ask which of these alternative interventions can help improve the severe pain associated with debridement, healing outcomes, debridement speed, and effectiveness or subsequent scarring when used within current surgical SOC protocols. It is important to recognize, as did the authors of both studies,^5,6 that lack of objective differential diagnosis of necrotic versus viable burned tissue at baseline has generated wide variability in subsequent treatment and outcomes throughout the clinical burn literature. Until consistent, objective baseline burn depth measurements are used, related variability between treatment groups will continue to cloud interpretations of burn debridement clinical efficacy. Meanwhile, the research summarized here suggests important opportunities to improve the SOC and outcomes for patients with deep partial- and full-thickness skin burns.