Improved Short-Term Prognosis of Pediatric Partial-Thickness Burns: Emergency Conservative Debridement Under Topical Anesthesia

OBJECTIVES

Early wound management for pediatric patients with partial-thickness burns in the emergency department remains debatable. This study aims to evaluate the value of emergency conservative debridement under topical anesthesia in improving short-term prognosis of pediatric partial-thickness burns.

METHODS

This retrospective cohort study enrolled children with partial-thickness thermal burns presenting to the emergency department within 6 hours postburn. All the enrolled patients were divided into 2 groups: the debridement group and the dressing group. The associations between emergency conservative debridement and time to reepithelialization was analyzed by using Kaplan-Meier curves with log rank test and multivariate Cox regression analysis. Moreover, the associations between emergency conservative debridement and in-hospital cost and length of stay were also evaluated.

RESULTS

All baseline characteristics between groups were comparable (all P > 0.05). Emergency conservative debridement under topical anesthesia significantly decreased the median value of time to reepithelialization (13 vs 14 days, P = 0.02). Cox regression analysis showed that emergency conservative debridement significantly improved wound reepithelialization after adjusting for burn size (odds ratio, 4.07; 95% confidence interval, 1.64-10.11; P < 0.01). The mean length of stay of patients receiving conservative wound debridement was lower than that of patients in the wound dressing group (14.3 ± 7.3 vs 18.8 ± 10.4 days, P < 0.01), but not in terms of mean in-hospital cost per 1% total body surface area (2.8 ± 1.9 vs 3.0 ± 2.1 × 103 RMB per 1% total body surface area, P = 0.58).

CONCLUSIONS

Emergency conservative debridement of pediatric partial-thickness burns under topical anesthesia significantly improves the wound healing outcomes without increasing health care burden.

Microneedle Patch for Transdermal Sequential Delivery of KGF-2 and aFGF to Enhance Burn Wound Therapy

Severe burn wounds usually destroy key cells' functions of the skin resulting in delayed re-epithelization and wound regeneration. Promoting key cells' activities is crucial for burn wound repair. It is well known that keratinocyte growth factor-2 (KGF-2) participates in the proliferation and morphogenesis of epithelial cells while acidic fibroblast growth factor (aFGF) is a key mediator for fibroblast and endothelial cell growth and differentiation. However, thick eschar and the harsh environment of a burn wound often decrease the delivery efficiency of fibroblast growth factor (FGF) to the wound site. Therefore, herein a novel microneedle patch for sequential transdermal delivery of KGF-2 and aFGF is fabricated to enhance burn wound therapy. aFGF is first loaded in the nanoparticle (NPaFGF) and then encapsulated NPaFGF with KGF-2 in the microneedle patch (KGF-2/NPaFGF@MN). The result shows that KGF-2/NPaFGF@MN can successfully get across the eschar and sequentially release KGF-2 and aFGF. Additional data demonstrated that KGF-2/NPaFGF@MN achieved a quicker wound closure rate with reduced necrotic tissues, faster re-epithelialization, enhanced collagen deposition, and increased neo-vascularization. Further evidence suggests that improved wound healing is regulated by significantly elevated expressions of hypoxia-inducible factor-1 alpha (HIF-1ɑ) and heat shock protein 90 (Hsp90) in burn wounds. All these data proved that KGF-2/NPaFGF@MN is an effective treatment for wound healing of burns.

Enzymatic debridement with bromelain and development of bacteremia in burn injuries: A retrospective cohort study

BACKGROUND

Debridement is crucial for effective wound management in patients with severe burn injuries, and bromelain, a proteolytic enzyme from pineapple stems, has emerged as a promising alternative for surgery. However, potential links of bromelain use to fever and sepsis have raised some concerns. Given the uncertainty as to whether this was caused by infection or other inflammatory sources, we aimed to investigate if the use of topical bromelain was associated with bacteremia.

METHODS

This single-centre retrospective cohort study included critically ill adult patients with severe burn injuries hospitalised at the Burn Center of the University Hospital Zurich between January 2017 and December 2021. Data were collected from two in-hospital electronic medical records databases. Our primary outcome, the association between topical bromelain treatment and the development of bacteremia, was investigated using a competing risk regression model, taking into account the competing risk of death. As a secondary outcome, the relationship between bromelain treatment and overall ICU mortality was examined using a Cox proportional hazards model.

RESULTS

The study included 269 patients with a median age of 50 years and median burnt total body surface area of 19%. A first bacteremia occurred in 61 patients (23%) after a median time of 6 days. Bromelain treatment was given to 83 (31%) of patients, with 22 (27%) of these developing bacteremia. In the fully adjusted competing risk regression model, no evidence for an association between bromelain treatment and bacteremia was found (SHR 0.79, 95%CI 0.42-1.48, p = 0.47). During hospital stay, 40 (15%) of patients died. There was no significant difference in mortality between patients treated with bromelain and those who were not (HR 0.55, 95%CI 0.26-1.20, p = 0.14). Among the five multidrug-resistant (MDR) pathogens identified, three were found in patients with bromelain treatment.

CONCLUSION

Our study did not confirm an association between topical bromelain and bacteremia in patients with severe burn injuries. This finding can inform evidence-based practices by addressing concerns about potential risks of bromelain use, contributing to the development of more effective and safe burn wound management strategies.

Feasibility of intra-operative image guidance in burn excision surgery with multispectral imaging and deep learning

BACKGROUND

Exposing a healthy wound bed for skin grafting is an important step during burn surgery to ensure graft take and maintain good functional outcomes. Currently, the removal of non-viable tissue in the burn wound bed during excision is determined by expert clinician judgment. Using a porcine model of tangential burn excision, we investigated the effectiveness of an intraoperative multispectral imaging device combined with artificial intelligence to aid clinician judgment for the excision of non-viable tissue.

METHODS

Multispectral imaging data was obtained from serial tangential excisions of thermal burn injuries and used to train a deep learning algorithm to identify the presence and location of non-viable tissue in the wound bed. Following algorithm development, we studied the ability of two surgeons to estimate wound bed viability, both unaided and aided by the imaging device.

RESULTS

The deep learning algorithm was 87% accurate in identifying the viability of a burn wound bed. When paired with the surgeons, this device significantly improved their abilities to determine the viability of the wound bed by 25% (p = 0.03). Each time a surgeon changed their decision after seeing the AI model output, it was always a change from an incorrect decision to excise more tissue to a correct decision to stop excision.

CONCLUSION

This study provides insight into the feasibility of image-guided burn excision, its effect on surgeon decision making, and suggests further investigation of a real-time imaging system for burn surgery could reduce over-excision of burn wounds.

Safety and efficacy of waterjet debridement vs. conventional debridement in the treatment of extremely severe burns: A retrospective analysis

INTRODUCTION

Patients with extremely severe burns often require rapid wound closure with a tangential excision or escharectomy combined with a skin graft to reduce life-threatening complications such as infection. Traditional tangential excision surgery using the Watson or Humby knife does not allow accurate excision of necrotic tissue and often removes too much active tissue, which is detrimental to the rapid healing of the wound. Importantly, the Versajet hydrosurgical system, with its smaller handle, allows for more precise excision of necrotic burn tissue and preserves more active dermal tissue, positively affecting wound healing and scarring. This study compared the safety and efficacy of hydrosurgical combined with autologous skin grafting to conventional excision combined with autologous skin grafting in patients with extremely severe burn.

METHODS

Information of sixty burn patients with total body surface area (TBSA) > 50 % treated at the first affiliated hospital of Anhui Medical University from January 2019 to August 2022 were analyzed. The patients were divided into a conventional debridement group (n = 37) and a hydrosurgical debridement group (n = 23) according to the approach used. The hydrosurgical debridement group and the conventional debridement group were compared from the difference between the duration of the first debridement surgery, wound healing time, the changes of red blood cells and hemoglobin concentration postoperative, total blood transfusion, hospitalization cost, skin grafting frequency, procalcitonin, wound bacterial culture, albumin and prealbumin.

RESULTS

Information on age, gender, weight, inhalation injury, hypovolemic shock, preoperative procalcitonin, preoperative albumin, preoperative prealbumin, the operation frequency (n ≥ 3), preoperative trauma culture and postoperative trauma culture were compared between both groups (P > 0.05). Operative time and wound healing time were significantly shorter in patients with hydrosurgical debridement combined with autologous skin grafting than those in the control group (P < 0.05), while hospitalization costs were not significantly different between the two groups (P > 0.05). The changes of red blood cells and hemoglobin concentration during the postoperative period in the hydrosurgical debridement group were less significantly than those in the conventional debridement group (P < 0.05). The total amount of red blood cells transfused during hospitalization was significantly lower in the hydrosurgical debridement group than that in the conventional debridement group (P < 0.05), but the total amount of fresh frozen plasma transfused during hospitalization was not statistically significant between the two groups (P > 0.05). Albumin on the third day after surgery and prealbumin on the first, third and fifth day after surgery improved more significantly than those in the control group(P < 0.05), however, there were no significant differences between the two groups in albumin on the first and fifth postoperative days (P > 0.05). The PCT level in the conventional debridement group was significantly higher than that in the hydrosurgical debridement group on the first, third and fifth days after surgery(P < 0.05).

CONCLUSION

The hydrosurgical debridement group presented with shorter operative time, less blood loss during surgery, faster postoperative nutritional recovery, less postoperative inflammatory response and faster wounds healing, and did not increase the hospitalization cost, postoperative bacterial culture of the wounds and the number of skin grafting surgeries. In patients with extremely severe burn, hydrosurgical debridement combined with autologous skin grafting group is safer and more effective than those in the conventional debridement combined with autologous skin grafting group.

ICG-mediated fluorescence-assisted debridement to promote wound healing

The purpose of this study was to examine the efficacy of ICG-mediated fluorescence molecular imaging (FMI) in debridement of necrotic tissue. 96 wound-infected rats were randomly divided into control group, ICG group, excitation light (EL)group and FMI group for debridement of necrotic tissue (n = 24). (I) Control group: only debridement; (II) ICG group: ICG injection before debridement; (III) EL group: Debridement under EL; (IV) FMI group: Debridement guided by ICG-mediated FMI. On the 3rd, 6th, and 9th days, the wound tissues of the rats in each group were collected for histological examination, and the levels of serum interleukin-4 (IL-4) and interferon-γ (INF-γ) were analyzed. The wound healing rate, wound score and body weight of the rats in each group were followed up until the wound healed. The results showed that the infected wounds of the rats in the FMI group had significant fluorescence development. The level of serum IL-4 in the FMI group was higher than that in the other three groups on the 6th day (p<0.01), while the level of INF-γ was lower than that in the other three groups on the 6th and 9th day (p<0.05). The results of dynamic wound tissue H&E staining indicated that the wound healing in the FMI group was better than the other three groups. The in vivo follow-up results showed that the wound healing rate and wound score of the FMI group were better than the other three groups, and the growth of rats had no difference with the other groups. ICG-mediated FMI can achieve accurate imaging of necrotic tissue for debridement, and so can accelerate wound healing, which has good clinical application prospects.

Anacaulase-bcdb for the treatment of severe thermal burns

INTRODUCTION

Accurate burn depth assessment and early excision of burn eschar with maximal dermal preservation are key concepts in the optimal care of burn injury. Although excision with knife has long since been standard of care, a newer technique for wound bed preparation utilizing a bromelain-based enzyme has gained popularity worldwide and may offer several advantages.

AREAS COVERED

Here we report the pharmacologic properties, evidence for clinical efficacy, safety, and tolerability of anacaulase-bcdb for the treatment of deep partial thickness and full thickness burns.

EXPERT OPINION

Anacaulase-bcdb is a safe, non-surgical, selective eschar removal agent. It offers advantages over surgical excision of burn with knife and fulfills two unmet needs: burn depth assessment and dermal preservation during excision. Evidence supports a faster time to complete eschar removal; reduced number of operations; reduction in the amount of autografting, length of stay, and blood loss; prevention of burn induced compartment syndrome; and improved cosmetic outcome.

To bleed or not to bleed? Case series and discussion of haemorrhage risk with enzymatic debridement in burn injuries

Introduction

Surgical burn excision (along with skin grafting) carries the risk of blood loss. The use of enzymatic debridement agents such as Nexobrid® has gained increased popularity as an alternative to surgical debridement in the management of burns with its reported benefits of selective burn debridement, minimising blood loss and potentially reducing the need for skin grafting. However, there is limited evidence regarding its effects on bleeding. Currently, the manufacturer declares there is no evidence for increased risk of localised bleeding and its systemic effects upon coagulation are less clear.

Methods

We present two clinical cases demonstrating the possible effects of Nexobrid® on coagulation and bleeding at the debridement site. Comparisons are drawn with the manufacturers' guidance as well as evaluating the current recommendations of its use.

Discussion

Nexobrid® is a novel therapy and there are few adverse effects reported in the literature. The basis of its appeal is the reduced blood loss at the debridement site and the selectivity it possesses in preserving healthy dermis. However, our cases have demonstrated that haemorrhage can occur and that those using Nexobrid® should be mindful of the potential bleeding risk from varicosities within the burn wound. We have also illustrated that Nexobrid® can be used in patients with pre-existing clotting disorders without requiring the use of blood products. However, we emphasise the importance of haematological support for its safe administration.

Lay Summary

Nexobrid®, a debriding agent that contains enzymes, has been developed as an alternative to surgery which for most surgeons is the traditional method of removing dead tissue following a burn injury. The active agent is bromelain and this is derived from the stems of pineapples. This novel treatment is increasingly being used in the management of middle to deep skin thickness burns and it seems to have a number of benefits such as reducing blood loss, reducing the need for skin grafting as well as being able to treat burns in certain areas of the body that would be technically challenging to remove in the standard fashion. It simply targets the dead tissue leaving viable remnants of the skin that would hopefully allow healing to occur without the need for surgical intervention. Being a relatively new concept, current evidence regarding the safety and value of Nexobrid® continues to develop. In 2020, an agreement guideline outlining best practice with the use of Nexobrid® was published. In this statement, it was advised that caution should be taken when using Nexobrid® in patients who have blood clotting disturbances as this could increase the likelihood of bleeding. However, they did not mention that excessive bleeding can potentially occur with this treatment.We present two clinical cases demonstrating the possible effects of Nexobrid® on the clotting system and bleeding at the application site. Comparisons are drawn with the manufacturers' guidance as well as assessing the current recommendations of its use. We illustrate that Nexobrid® can be safely used in patients with pre-existing clotting disturbances if the correct procedures are performed. We also highlight the potential complication of excessive bleeding if Nexobrid® is used in patients who have co-existing enlarged surface veins along with their burn injury. We feel the guidance should be updated to reflect these findings.

Chitosan degradation products promote healing of burn wounds of rat skin

Burns can impair the barrier function of the skin, and small burns can also cause high mortality. The WHO has described that over 180,000 people die of burns worldwide each year. Thus, the treatment of burn wounds is a major clinical challenge. Chitooligosaccharides (COS) are alkaline amino oligosaccharides with small molecular weights obtained by enzyme or chemical degradation of chitosan. With the characteristics of biocompatibility, water solubility and degradability, it has attracted increasing attention in the fields of biomedicine. In the present study, we used COS to treat deep second-degree burn wounds of rat skin and found that COS was able to promote wound healing. We also revealed that COS could promote fibroblast proliferation. Transcriptome sequencing analysis was performed on COS-treated fibroblasts to identify the underlying mechanisms. The results showed that COS was able to promote wound healing through regulation of the mitogen-activated protein kinase (MAPK) pathway and growth factor Hepatocyte Growth Factor (HGF). Our results provide a potential drug for burn wound therapy and the related molecular mechanism.

Indocyanine Green Angiography Precise Marking for Indeterminate Burn Excision: A Prospective, Multi-centered, Double-blinded Study

BACKGROUND

During burn excision, the clinical judgment whether to excise or not excise the area with indeterminate burn depth is difficult. Indocyanine green angiography (ICGA) has been reported to provide high accuracy in diagnosing indeterminate burns. This study aims to evaluate the complete wound closures in both short-term and long-term outcomes after using ICGA precise marking to guide indeterminate burn excision.

METHODS

This was a prospective, multi-centered, double-blinded, experimental study. The participants were admitted to the hospital with indeterminate burn wounds. ICGA precise marking was performed. The deep second-degree burn was painted, excised, and subsequently covered with skin grafts and measured on day 5. The superficial burns were measured on day 21. All wounds were followed-up at two months.

RESULTS

Thirty indeterminate burn sites were included in this study. Using ICGA precise marking, the overall rate of short-term complete wound closure, which combined superficial and deep burns, was found to be as high as 96.7% (29/30). The long-term complete wound closures at two months confirmed the short-term result and yielded 100.0% of complete wound closure. The complete wound closures between the short-term and long-term measurements were not significantly different (P > 0.999).

CONCLUSIONS

Using ICGA precise marking to guide indeterminate burn excision resulted in an excellent rate of complete wound closure and an insignificant difference between short-term and long-term wound outcomes. ICGA is a competent method to aid decision-making in burn surgery of the indeterminate area.

Historical Perspectives on the Development of Current Standards of Care for Enzymatic Debridement

Background and Objective: The use of plant-based products for burn treatment dates back to 1600 BC. Enzymatic debridement, which can be achieved as non-surgical or conservative debridement, has recently gained increasing attention. Several reviews have been published thus far. However, there has been no historical article including the achievements of the last 20 years, and this is the first review to present the achievements made in the field of enzymatic debridement in the last 20 years. This study aimed to present a historical overview of the development of enzymatic debridement until the present day. Methods: Enzymes from bacteria and plants were initially used for full-thickness burn treatment; however, they did not gain attention. Papain-derived products were the first plant-based products used for enzymatic debridement. Sutilains gained broad use in the 70s and 80s but came off market in the 1990s. Bromelain has been used for burn treatment owing to its strong debriding properties. NexoBrid^™ is used as a minimally invasive approach for enzymatic debridement of deep dermal burns. However, its use has been limited due to commercially available bromelain and the presence of four distinct cysteine proteinases. NexoBrid^™ involves faster eschar removal together with reduced blood loss, leading to improved long-term outcomes. However, research on nonoperative enzymatic debridement of burns has taken decades and is still ongoing. Results: Overall, the results of our study indicate that necrectomy, which has been used for a long time, remains the standard of care for burns. However, enzymatic debridement has several advantages, such as faster eschar removal, reduced blood loss, and reduced need for skin grafting, especially in cases of facial and hand burns. Enzymatic debridement cannot replace surgical intervention, as the enzyme only works on the surface of the eschar. Enzymatic debridement is not recommended in the early phase of scald burns. Conclusions: Enzymatic debridement has become an integral part of burn therapy and the standard of care in specific burn centers.

Hydrosurgical debridement versus conventional surgical debridement for acute partial-thickness burns

BACKGROUND

Burn injuries are the fourth most common traumatic injury, causing an estimated 180,000 deaths annually worldwide. Superficial burns can be managed with dressings alone, but deeper burns or those that fail to heal promptly are usually treated surgically. Acute burns surgery aims to debride burnt skin until healthy tissue is reached, at which point skin grafts or temporising dressings are applied. Conventional debridement is performed with an angled blade, tangentially shaving burned tissue until healthy tissue is encountered. Hydrosurgery, an alternative to conventional blade debridement, simultaneously debrides, irrigates, and removes tissue with the aim of minimising damage to uninjured tissue. Despite the increasing use of hydrosurgery, its efficacy and the risk of adverse events following surgery for burns is unclear.

OBJECTIVES

To assess the effects of hydrosurgical debridement and skin grafting versus conventional surgical debridement and skin grafting for the treatment of acute partial-thickness burns.

SEARCH METHODS

In December 2019 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled people of any age with acute partial-thickness burn injury and assessed the use of hydrosurgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, data extraction, 'Risk of bias' assessment, and GRADE assessment of the certainty of the evidence.

MAIN RESULTS

One RCT met the inclusion criteria of this review. The study sample size was 61 paediatric participants with acute partial-thickness burns of 3% to 4% total burn surface area. Participants were randomised to hydrosurgery or conventional debridement. There may be little or no difference in mean time to complete healing (mean difference (MD) 0.00 days, 95% confidence interval (CI) -6.25 to 6.25) or postoperative infection risk (risk ratio 1.33, 95% CI 0.57 to 3.11). These results are based on very low-certainty evidence, which was downgraded twice for risk of bias, once for indirectness, and once for imprecision. There may be little or no difference in operative time between hydrosurgery and conventional debridement (MD 0.2 minutes, 95% CI -12.2 to 12.6); again, the certainty of the evidence is very low, downgraded once for risk of bias, once for indirectness, and once for imprecision. There may be little or no difference in scar outcomes at six months. Health-related quality of life, resource use, and other adverse outcomes were not reported.

AUTHORS' CONCLUSIONS

This review contains one randomised trial of hydrosurgery versus conventional debridement in a paediatric population with low percentage of total body surface area burn injuries. Based on the available trial data, there may be little or no difference between hydrosurgery and conventional debridement in terms of time to complete healing, postoperative infection, operative time, and scar outcomes at six months. These results are based on very low-certainty evidence. Further research evaluating these outcomes as well as health-related quality of life, resource use, and other adverse event outcomes is required.

Enzymatic debridement of hands with deep burns: a single center experience in the treatment of 52 hands

Background: Bromelain-based enzymatic debridement has been introduced as an alternative to surgical excision in deep partial thickness and full thickness burns. We aimed to analyze effectiveness and predictors of spontaneous epithelialization after enzymatic debridement of deep hand burns.Methods: All patients who received enzymatic debridement for deep partial thickness or full thickness burns of the hands at our institution in the last 5 years were identified. Demographic, clinical and outcome data were collected and analyzed. For patients with deep partial thickness burns, Kaplan-Meier log-rank and subsequent multivariate Cox-regression analysis were performed to identify predictors of spontaneous epithelialization.Results: 44 patients and 52 hands were treated in the observation period. Among these, 14 had full thickness burns and received split thickness skin grafts. In the 38 hands with deep partial thickness burns, predictors of 28-day epithelialization were total burn extent and mechanism of burn injury. During the first 3 years, 8 out of 13 treated deep partial thickness burns received split thickness skin grafts after a median of 3 days. The following 3 years, 5 out of 25 deep partial thickness burns received surgery after a median of 14 days.Conclusions: Enzymatic debridement is a useful tool in the treatment of burned hands but the decision-making and correct timing of operative intervention in deep partial thickness burns after debridement requires experience. In our cohort, spontaneous healing of deep partial thickness burns was best in patients with contact burns and less than 15% burn TBSA.

Selective debridement of burn wounds using hydrosurgery system

In recent years, hydrosurgery is a technology that has been applied more and more in debridement procedures. However, the selectivity of hydrosurgery to cutaneous necrotic tissues has not been proved. This study was designed to investigate the possible tissue selectivity of hydrosurgery in the debridement in burn wounds. Deep partial-thickness burns were produced on the back of porcine, and 48 hours later, both burn wounds and normal skin were debrided using the hydrosurgery system. Then tissue samples were taken, and histological staining was performed and observed under microscope. Burn wound resection rates and the normal skin damaged rates were measured. Our result indicated that the burn wounds were significantly more sensitive than the normal skin when the water pressure produced by the hydrosurgery system was set between 3000 and 5000 psi (pounds per square inch), that is, the necrotic tissue portions were debrided more easily than the normal skin tissue. Based on these data, we suggest that 3000 to 5000 psi of water pressure in the hydrosurgery system has a skin tissue selectivity in burn wounds.

Effect of Bromelain-Based Enzymatic Debridement on Skin Cells

Several reports have concluded that enzymatic debridement based on Bromelain (NX) is selective and efficient. Although clinical trials showed that viable tissue is not damaged at the macroscopic level, the effect on the cellular level is largely unknown. The current study is meant to close this gap by evaluating whether NX has an effect on vital cells of the human dermis on a cellular level. In an experimental in vitro study design, the effect of NX on human keratinocytes, fibroblasts, and macrophages was analyzed. Enzymatic treatment was performed for 4 hours by using either cell culture medium or phosphate-buffered saline as diluting agent for NX. Cell viability and relative cell number in relation to untreated control cells were determined using a resazurin-based assay. In addition, the development of enzyme activity during clinical treatment was analyzed: wound fluid collected from a burn wound at different points of debridement was applied on collagen-elastin disks to prove enzymatic digestion activity. Both keratinocytes and fibroblasts were damaged by NX even at low concentrations. Both cell types showed improved survival when a medium was used for dissolving NX. Macrophages appeared to resist NX treatment more efficiently than the other cell types. In the clinical trial, NX activity in the wound fluid decreased clearly following 4 hours of enzymatic debridement. NX induces toxicity of vital skin cells in vitro. However, macrophages appear to be more resistant against NX treatment in vitro. The inflammatory responses of vital cells in the burn wound itself are likely to inhibit NX activity. The effect of this inflammatory process on NX activity will have to be investigated in future studies.

Long-term scar quality after hydrosurgical versus conventional debridement of deep dermal burns (HyCon trial): study protocol for a randomized controlled trial

Background

Deep dermal burns require tangential excision of non-viable tissue and skin grafting to improve wound healing and burn-scar quality. Tangential excision is conventionally performed with a knife, but during the last decade hydrosurgery has become popular as a new tool for tangential excision. Hydrosurgery is generally thought to be a more precise and controlled manner of burn debridement leading to preservation of viable tissue and, therefore, better scar quality. Although scar quality is considered to be one of the most important outcomes in burn surgery today, no randomized controlled study has compared the effect of these two common treatment modalities with scar quality as a primary outcome. The aim of this study is, therefore, to compare long-term scar quality after hydrosurgical versus conventional tangential excision in deep dermal burns.

Methods/design

A multicenter, randomized, intra-patient, controlled trial will be conducted in the Dutch burn centers of Rotterdam, Beverwijk, and Groningen. All patients with deep dermal burns that require excision and grafting are eligible. Exclusion criteria are: a burn wound < 50 cm², total body surface area (TBSA) burned > 30%, full-thickness burns, chemical or electrical burns, infected wounds (clinical symptoms in combination with positive wound swabs), insufficient knowledge of the Dutch or English language, patients that are unlikely to comply with requirements of the study protocol and follow-up, and patients who are (temporarily) incompetent because of sedation and/or intubation. A total of 137 patients will be included. Comparable wound areas A and B will be appointed, randomized and either excised conventionally with a knife or with the hydrosurgery system. The primary outcome is scar quality measured by the observer score of the Patient and Observer Scar Assessment Scale (POSAS); a subjective scar-assessment instrument, consisting of two separate six-item scales (observer and patient) that are both scored on a 10-point rating scale.

Discussion

This study will contribute to the optimal surgical treatment of patients with deep dermal burn wounds.

Trial registration

Dutch Trial Register, NTR6232. Registered on 23 January 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2599-2) contains supplementary material, which is available to authorized users.

Burn-injured tissue detection for debridement surgery through the combination of non-invasive optical imaging techniques

The process of burn debridement is a challenging technique requiring significant skills to identify the regions that need excision and their appropriate excision depths. In order to assist surgeons, a machine learning tool is being developed to provide a quantitative assessment of burn-injured tissue. This paper presents three non-invasive optical imaging techniques capable of distinguishing four kinds of tissue-healthy skin, viable wound bed, shallow burn, and deep burn-during serial burn debridement in a porcine model. All combinations of these three techniques have been studied through a k-fold cross-validation method. In terms of global performance, the combination of all three techniques significantly improves the classification accuracy with respect to just one technique, from 0.42 up to more than 0.76. Furthermore, a non-linear spatial filtering based on the mode of a small neighborhood has been applied as a post-processing technique, in order to improve the performance of the classification. Using this technique, the global accuracy reaches a value close to 0.78 and, for some particular tissues and combination of techniques, the accuracy improves by 13%.

Burn Wound Healing and Tissue Engineering

In 2016 the American Burn Association held a State of the Science conference to help identify burn research priorities for the next decade. The current paper summarizes the work of the sub-committee on Burn Wound Healing and Tissue Engineering. We first present the priorities in wound healing research over the next 10 years. We then summarize the current state of the science related to burn wound healing and tissue engineering including determination of burn depth, limiting burn injury progression, eschar removal, management of microbial contamination and wound infection, measuring wound closure, accelerating wound healing and durable wound closure, and skin substitutes and tissue engineering. Finally, a summary of the round table discussion is presented.

Steel Wool-Aided Dermabrasion of Deep Partial-Thickness Burns

Early tangential excision of the burn wound is essential for removal of necrotic tissue and promotion of burn wound healing process. However, the depth of the burn wound is not easily assessed during the tangential excision performed by hand-held dermatomes, and it may be possible to excise unburned vital dermis unnecessarily, which aids in primary epithelization of the burn wound by adnexal structures. We herein present early clinical results of steel wool-aided dermabrasion in patients with deep partial-thickness burns. This is a retrospective case study of 23 consecutive hospitalized patients with deep partial-thickness burns. All of the steel wool-aided dermabrasions were performed under general anesthesia within 48 hours after injury. Patients were excluded from the study if the admission was not within 24 hours after injury, and if the burn wound was entirely superficial partial- or full-thickness. Thirteen male and 10 female patients with a mean age of 26.2 ± 17.1 years were enrolled in the study. During the follow-up period, all of the patients had burn wounds primary epithelized on postburn day 15.1 ± 1.8, without any complications. None of the patients exhibited a mortal course, and redebridement or skin grafting of the previously dermabraded deep partial-thickness burn wounds were not required in any of the patients. Steel wool-aided dermabrasion is an easy, cost-effective, and reliable technique for the treatment of deep partial-thickness burns, which provides complete removal of necrotic tissue, preserves the vital dermis, reduces the requirement for skin grafting, and decreases length of hospital stay.

An optimized staining technique for the detection of Gram positive and Gram negative bacteria within tissue

BACKGROUND

Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue.

FINDINGS

A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue.

CONCLUSIONS

We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host tissue. The samples used in this study demonstrate that this staining technique has laboratory and clinical applicability. This modification only adds minutes to traditional Gram stain with reusable reagents, and results in a cost- and time-efficient technique for identifying bacteria in any clinical biopsy containing connective tissue.

Use of porcine acellular dermal matrix following early dermabrasion reduces length of stay in extensive deep dermal burns

OBJECTIVE

Extensive deep partial-thickness burns still seriously challenge the surgeon's abilities. This study aimed to assess the impact of early dermabrasion combined with porcine acellular dermal matrix (ADM) in extensive deep dermal burns.

METHODS

From September 2009 to September 2013, a total of 60 adult patients sustained greater than 50% total body surface area (TBSA) burn by hot water or gas explosion were divided into three groups based on dermabrasion: group A (early dermabrasion and porcine ADM), group B (early dermabrasion and nano-silver dressings), and group C (conservative group). The wound healing time and length of hospital stay were analyzed. Scar assessment was performed at 3 and 12 months after the injury with a modified Vancouver Scar Scale linked with TBSA (mVSS-TBSA).

RESULTS

No significant difference was found in mean burn size, burn depth, age, male-to-female ratio, or incidence of inhalation injury between the patients in the three groups (p>0.05). Compared with groups B and C, the patients that received early dermabrasion combined with porcine ADM had a shorter wound healing time (p<0.01). The burn patients treated with early dermabrasion and porcine ADM coverage had a mean length of hospital stay of 28.3 days (±7.2), which was significantly shorter than that of groups B and C (p<0.05-0.01). The mVSS-TBSA of patients in group A was significantly improved in comparison with groups B and C at 3 and 12 months after the injury. There was no significant difference in the mortality rate between the three groups (p>0.05).

CONCLUSION

Early dermabrasion combined with porcine ADM coverage facilitates wound healing, reduces the length of hospital stay, and improves esthetic and functional results in extensive deep dermal burns with burn size over 50% TBSA.

The estimation of tissue loss during tangential hydrosurgical debridement

The preservation of healthy tissue during surgical debridement is desirable as this may improve clinical outcomes. This study has estimated for the first time the amount of tissue lost during debridement using the VERSAJET system of tangential hydrosurgery. A multicenter, prospective case series was carried out on 47 patients with mixed wound types: 21 (45%) burns, 13 (28%) chronic wounds, and 13 (28%) acute wounds. Overall, 44 (94%) of 47 patients achieved appropriate debridement after a single debridement procedure as verified by an independent photographic assessment. The percentage of necrotic tissue reduced from a median of 50% to 0% (P < 0.001). Median wound area and depth increased by only 0.3 cm (6.8%) and 0.5 mm (25%), respectively. Notably, 43 (91%) of 47 wounds did not progress into a deeper compartment, indicating a high degree of tissue preservation.

Selectivity of a bromelain based enzymatic debridement agent: a porcine study

BACKGROUND

Debridement of the burn eschar is a cornerstone of burn wound care. Rapid enzymatic debridement with a bromelain-based agent (Debriding Gel Dressing-DGD) has recently been investigated. The current study was designed to further investigate the selectivity of DGD to burned eschar in a larger number and more varied types of wounds.

METHODS

A systematic animal experiment was conducted to determine the effects of DGD on normal, non-injured skin, burns, exposed dermis of donor sites, and skin punch biopsy wells. Partial thickness dermal burns and partial thickness skin graft donor sites were created on a pig and treated with a 4-h application of DGD or its control hydrating vehicle that does not have any activity except hydration. Punch biopsy samples were taken before and after treatment and microscopically assessed for evidence of tissue viability and its respective components thickness.

RESULTS

Rapid dissolution of the burn eschar was noted in all DGD but not vehicle treated burns. There was no apparent damage to the underlying sub eschar dermis, donor sites, normal skin or punch biopsy wells after exposure to DGD. While the thickness of the treated tissues slightly increased due to edema, the increase in dermal thickness was similar after treatment with DGD or its vehicle. The increase in the cross section surface area of the treated punch biopsy wells was similar after treatment with DGD and its control vehicle.

CONCLUSIONS

Exposure of the burn eschar to DGD results in its rapid dissolution. Exposure of normal skin or non-burned dermis to DGD has no effects demonstrating its selectivity to eschar.